Lavoro nel laboratorio di Bunz presso il Georgia Institute of Technology è stato sostenuto in parte dalla National Science Foundation (NSF-CHE 07.502.753) e il lavoro a Ruprecht-Karls-Universität di Heidelberg è stato finanziato dalla &quot;Struktur und Innovationsfond des Landes Baden-Württemberg&quot;. Lavoro nel laboratorio di Miljanić presso l&#39;Università di Houston è stato finanziato dal programma National Science Foundation CARRIERA (CHE-1.151.292), la Welch Foundation (concessione n. E-1768), l&#39;Università di Houston (UH) e il suo programma Piccolo Grant, e il Centro Texas per la superconduttività a UH.

1. Rilevazione degli acidi carbossilici utilizzando Distyrylbis (arylethynyl) benzene crucimorfi <ol><li> Preparare una soluzione madre fresca di crucimorfi 1-3 con una concentrazione di 1,0 x 10 -3 mol / L in DCM. Non è necessario usare solventi qualità spettroscopica; ACS purezza per reagenti è sufficiente. </li><li> Utilizzando le soluzioni stock di 1,1 preparare 100 ml ciascuna di 2,0 x 10 -6 M di soluzione 1-3 in diclorometano (DCM), acetato di etile (EtOAc), acetonitrile (AN), N, N-dimetilformammide (DMF), alcool isopropilico (i PrOH) e metanolo (MeOH). Non è necessario usare solventi qualità spettroscopica; ACS purezza per reagenti è sufficiente. </li><li> Pesare 0,65 mmol (88,2-124,2 mg) dell&#39;analita carbossilico A1 - A10 in 5 ml dram fiale, aggiungere 5 ml delle soluzioni preparate in 2.1 e agitare il flaconcino. Se eterogeneo, la soluzione corrispondente deve essere lasciata riposare (filtraggio non è necessario). Ciò porta ad un totale concentrazione di 0,13 M (31 g / L) dell&#39;acido carbossilico. </li><li> Catturare fotografie digitali della fluorescenza in una stanza buia in assenza di luce. Il setup fotografico (Figura 2) include una fotocamera digitale (Canon EOS 30D) dotata di un obiettivo (EFS 18-55 mm zoom) e due lampade UV (lunghezza d&#39;onda di eccitazione di 365 nm). Le fiale non ridotte devono essere posizionati sotto le due lampade UV per l&#39;esposizione massima con una distanza di 60 cm tra fotocamera e fiale campione. I tempi di esposizione sono state variate per ogni soluzione per produrre immagini che riflettono il colore di emissione (0,25-15 sec). </li></ol> 2. Ricerca di acidi boronico Uso Benzobisoxazole crucimorfi <ol><li> Preparare una soluzione M 10 x 1,0 -4 di cruciforme 4 in DCM. Non è necessario usare qualità spettroscopica solvente; ACS purezza per reagenti è sufficiente. </li><li> Preparare cinque soluzioni individuali per ciascun analita acido boronico, sciogliendo 50 mg (0,24-0,41 mmol)dell&#39;analita in 3 ml ciascuna di acetonitrile (AN), 1,2,4-triclorobenzene (TCB), diclorometano (DCM), cicloesano (CH), e clorobenzene (CB). Questo dovrebbe portare a ca. 16.7 g / L soluzioni rispetto a ciascun analita. Non è necessario usare solventi qualità spettroscopica; ACS purezza per reagenti è sufficiente. </li><li> Trasferire 1,8 ml di ciascuna delle soluzioni di analita preparate in 2.2 in cinque 10 x 10 mm cuvette di quarzo separati (comunemente usato per spettroscopia UV / Vis). Quindi, aggiungere 20 ml della soluzione di cruciforme preparata in 2.1 in ciascuna delle cinque provette e mescolare le due soluzioni per omogeneizzare. Se si osserva qualsiasi precipitazione, la soluzione corrispondente dovrebbe semplicemente essere lasciata riposare (filtraggio non è necessario). </li><li> Posizionare tutti i cinque cuvette su una lastra di vetro e irradiare loro da una lampada UV palmare (365 nm) dall&#39;alto. La lampada UV deve essere posizionata in modo da assicurare un irraggiamento a tutti e cinque fiale. </li><li> Assicurarsi che la stanza è dark (spegnere le luci, finestre di blocco e di altre fonti di luce naturale e artificiale) e di prendere immediatamente una fotografia digitale dei colori di emissione delle soluzioni. Miljanić et al. hanno utilizzato due modelli di fotocamere digitali: Fujifilm FinePix S9000 e Canon EOS Rebel T3i, con una distanza di 45 centimetri tra l&#39;obiettivo della fotocamera e le cuvette del campione. Velocità otturatore era di 0,5 sec. </li></ol> 3. Rilevazione di analiti Amine Uso Cruciform Benzobisoxazole / boronico Acidi Sensing System Hybrid <ol><li> Preparare (almeno) 80 ml ​​ciascuna di 1,0 x 10 -6 M di soluzioni cruciforme 4 in acetonitrile (AN), 1,2,4-triclorobenzene (TCB), cicloesano (CH), diclorometano (DCM) e cloroformio (CF ). </li><li> Sciogliere B1 (152,6 mg, 0,80 mmol) in 40 ml di ciascuna delle soluzioni preparate in 3.1. </li><li> Sciogliere B5 (97.6 mg, 0.80 mmol) in 40 ml di ciascuna delle soluzioni preparate in 3.1. </li><li> Subito dopo le soluzioni descritte in 3.2 e 3.3 sono preparati, utilizzare ilm (2 ml ciascuna) per sciogliere l&#39;analita ammina desiderata (40 mg, 0,19-0,47 mmol). Per ogni analita ammina, dieci soluzioni devono essere preparate: cinque con B1 e cinque con B5 come additivi. Non è necessario usare solventi qualità spettroscopica; ACS purezza per reagenti è sufficiente. </li><li> Per ogni analita, trasferire aliquote dei dieci preparati analiti / boronic acid / cruciforme 4 soluzioni in dieci cuvette di quarzo separati. Posizionare questi due set di cinque Cuvetta (uno per 4/B1, uno per 4/B5) su una lastra di vetro, irradiano a 365 nm di una lampada UV tenuto in mano, e subito fotografare usando le impostazioni descritte in 2.5. </li></ol> 4. Image Processing e numerico Analita discriminazione <ol><li> Utilizzo di Adobe Photoshop o un programma di elaborazione delle immagini simili, tagliare un segmento quadrato rappresentante di fotografie digitali dei colori di emissione di ciascun flacone fotografato. Organizzare questi ritagli in pannelli simili a quelli nelle figure 3B, 4, e 5 </strong&gt;. Questi pannelli, in molti casi consentono una rapida discriminazione ad occhio nudo tra analiti. </li><li> Se si desidera una quantificazione delle differenze di colore di emissione, i valori di R / G / B possono essere estratti da pannelli in 4.1 e poi trattati statisticamente. Liberamente scaricabile Colour Contrast Analyzer 14 può essere utilizzato per questo scopo. Avere deviazioni standard relative colori di emissione di un analita relativo ad un altro (ad esempio composti B1 e B2, figura 4), ​​la seguente equazione è utilizzato: <img alt="Equazione 1" src="/files/ftp_upload/50858/50858eq1.jpg" /></li><li> L&#39;equazione da 4.2 viene inoltre utilizzato per identificare sconosciuti analiti acido carbossilico. Quindi ogni scostamento è determinato tra l&#39;analita sconosciuto a tutte le sostanze del set di dati di calibrazione. La più piccola deviazione indica la sostanza corrispondente. </li></ol>

<ol>
	<li>Zucchero, A. J., McGrier, P. J., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cross-conjugated+cruciform+fluorophores.">Cross-conjugated cruciform fluorophores.</a> Acc. Chem. Res. 43 (3), 397-408 (2010).</li><li>Feldman, A. K., Steigerwald, M. L., Guo, X., Nuckolls, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+electronic+devices+based+on+single-walled+carbon+nanotube+electrodes.">Molecular electronic devices based on single-walled carbon nanotube electrodes.</a> Acc. Chem. Res. 41 (12), 1731-1741 (2008).</li><li>Galbrecht, F., B&#252;nnagel, T., Bilge, A., Scherf, T. J. J., M&#252;ller, U. H. F., Bunz, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Functional Organic Materials. , 83 (2007).</li><li>Marsden, J. A., Miller, J. J., Shirtcliff, L. D., Haley, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure-property+relationships+of+donor/acceptor-functionalized+tetrakis(phenylethynyl)benzenes+and+bis(dehydrobenzoannuleno)+benzenes.">Structure-property relationships of donor/acceptor-functionalized tetrakis(phenylethynyl)benzenes and bis(dehydrobenzoannuleno) benzenes.</a> J. Am. Chem. Soc. 127 (8), 2464-2476 (2005).</li><li>Lim, J., Albright, T. A., Martin, B. R., Miljani&#263;, O. &. #. 3. 5. 2. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzobisoxazole+cruciforms:+heterocyclic+fluorophores+with+spatially+separated+frontier+molecular+orbitals.">Benzobisoxazole cruciforms: heterocyclic fluorophores with spatially separated frontier molecular orbitals.</a> J. Org. Chem. 76 (24), 10207-10219 (2011).</li><li>Lirag, R. C., Le, H. T. M., Miljani&#263;, O. &. #. 3. 5. 2. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=L-shaped+benzimidazole+fluorophores:+synthesis,+characterization+and+optical+response+to+bases,+acids+and+anions.">L-shaped benzimidazole fluorophores: synthesis, characterization and optical response to bases, acids and anions.</a> Chem. Commun. , (2013).</li><li>Hauck, M., Schoenhaber, J., Zucchero, A. J., Hardcastle, K. I., Mueller, T. J. J., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenothiazine+cruciforms:+synthesis+and+metallochromic+properties.">Phenothiazine cruciforms: synthesis and metallochromic properties.</a> J. Org. Chem. 72 (18), 6714-6725 (2007).</li><li>Zucchero, A. J., Wilson, J. N., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cruciforms+as+functional+fluorophores:+response+to+protons+and+selected+metal+ions.">Cruciforms as functional fluorophores: response to protons and selected metal ions.</a> J. Am. Chem. Soc. 128 (36), 11872-11881 (2006).</li><li>Wilson, J. N., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switching+of+intramolecular+charge+transfer+in+cruciforms:+metal+ion+sensing.">Switching of intramolecular charge transfer in cruciforms: metal ion sensing.</a> J. Am. Chem. Soc. 127 (12), 4124-4125 (2005).</li><li>Davey, E. A., Zucchero, A. J., Trapp, O., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discrimination+of+organic+acids+using+a+three+molecule+array+based+upon+cruciform+fluorophores.">Discrimination of organic acids using a three molecule array based upon cruciform fluorophores.</a> J. Am. Chem. Soc. 133 (20), 7716-7718 (2011).</li><li>Lim, J., Nam, D., Miljani&#263;, O. &. #. 3. 5. 2. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+carboxylic+and+organoboronic+acids+and+phenols+with+a+single+benzobisoxazole+fluorophore.">Identification of carboxylic and organoboronic acids and phenols with a single benzobisoxazole fluorophore.</a> Chem. Sci. 3 (2), 559-563 (2012).</li><li>Lim, J., Miljani&#263;, O. &. #. 3. 5. 2. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzobisoxazole+fluorophore+vicariously+senses+amines,+ureas,+anions.">Benzobisoxazole fluorophore vicariously senses amines, ureas, anions.</a> Chem. Commun. 48 (83), 10301-10303 (2012).</li><li>Braga, D., Polito, M., Bracaccini, M., D'Addario, D., Tagliavini, E., Sturba, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+organometallic+building+blocks+for+molecular+crystal+engineering.+2.+Synthesis+and+characterization+of+pyridyl+and+pyrimidyl+derivatives+of+diboronic+acid,+Fe(&#951;5-C5H4+-+B(OH)2)2],+and+of+pyridyl+boronic+acid,+[Fe(&#951;5-C5H4-4-C5H4N)(&#951;5-C5H4+-+B(OH)2)].">Novel organometallic building blocks for molecular crystal engineering. 2. Synthesis and characterization of pyridyl and pyrimidyl derivatives of diboronic acid, Fe(&#951;5-C5H4 - B(OH)2)2], and of pyridyl boronic acid, [Fe(&#951;5-C5H4-4-C5H4N)(&#951;5-C5H4 - B(OH)2)].</a> Organometallics. 22 (10), 2142-2150 (2003).</li><li>Schwaebel, T., Trapp, O., Bunz, U. H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Digital+photography+for+the+analysis+of+fluorescence+responses.">Digital photography for the analysis of fluorescence responses.</a> Chem. Sci. 4 (3), 273-281 (2013).</li></ol>

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I protocolli per la discriminazione qualitativa descritta in questo documento e video detengono un potenziale significativo in analisi di qualità di routine, dove anche un operatore minimamente addestrato poteva scorgere le differenze di composizione, o deviazioni da una formula ben definita. La praticità di questa tecnica potrebbe essere ulteriormente migliorata utilizzando semplici telecamere cellulare, che, in combinazione con il software di disegno e immagine riconoscimento come Google Goggles, potrebbero corrispo...

Crucimorfi molecolari sono definite come X-shaped cross-molecole coniugate in cui due circuiti di coniugazione si intersecano in un nucleo centrale. 1,2,3 Con un appropriato sostituzione donatore-accettore, queste molecole possono spazialmente localizzare i loro orbitali molecolari di frontiera (QOR), in modo che il più alto orbitale molecolare occupato (HOMO) risiede prevalentemente lungo l&#39;asse ricco di elettroni della molecola, mentre il più basso orbitale molecolare non occupato (LUMO) presenta il grosso della sua densità posizionata lungo il braccio elettron-poveri della molecola. Tale isolamento spaziale di FMO è essenziale nelle applicazioni di questi crucimorfi come sensori per le piccole molecole, poiché legame al cruciforme analita invariabilmente cambia il proprio gap HOMO-LUMO e le proprietà ottiche associate. Questo comportamento è stato dimostrato in crucimorfi basati su 1,4-distyryl-2 ,5-bis (arylethynyl) benzene, 1 1,2,4,5-tetrakisethynylbenzene, 4 e 5,6 benzobisoxazole strutturalemotivi. Dal momento che tutte e tre le classi di molecole sono intrinsecamente fluorescente, questa metodologia ha permesso il loro uso come sensori di piccole molecole. In tutti e tre gli esempi, crucimorfi sono stati sostituiti con Lewis base piridina e gruppi dialkylaniline ed erano così sensibili alle Lewis acide analiti, come i protoni e ioni metallici. 1,4,5,7,8,9 Nel 2011, Bunz e collaboratori hanno dimostrato che le risposte 10 fluorescenza di 1,4-distyryl-2 ,5-bis (arylethynyl) benzene crucimorfi: 1 - 3 (Figura 1) varia notevolmente a seconda della struttura dell&#39;acido carbossilico utilizzato per indurre protonazione della croce. Successivamente, Miljanić et al. Hanno dimostrato che benzobisoxazole crucimorfi come 4 (Figura 1) mostrano anche molto specifiche risposte di emissione di fluorescenza di acidi carbossilici strutturalmente correlate, e che simile distinzione può essere visto tra gli acidi organoboronici molto simili, anche. Undici origini di questaaltamente selettivi cambiamenti di colore di emissione sono al momento poco chiare, e sono probabilmente complesse - come quenching di fluorescenza da parte di elettroni analiti poveri, residuo analita fluorescenza e protonazione indotta spostamento di crucimorfi &#39;emissione maxima tutti presumibilmente giocare un ruolo. Ciononostante, la capacità di discriminare tra analiti strutturalmente correlate è significativo, soprattutto perché statisticamente rilevante distinzione può essere ottenuta senza la necessità di eseguire esaustivo UV / Vis assorbimento o fluorescenza caratterizzazione della risposta ottica di crucimorfi verso analiti. Invece, fotografie semplici di colore emissione sono sufficientemente distinte da consentire la discriminazione tra analiti strutturalmente strettamente legate, soprattutto se le fotografie sono prese in differenti solvente o con più di un sensore cruciforme. Usando questa metodologia pratica, decine di analiti possono essere rapidamente analizzati in un pomeriggio (vedi pannelli in figure 3-5), mentre la stessa analisi richiederebbesettimane se è stata impiegata la spettroscopia rigoroso. Inoltre, poiché acidi boronico sono specie dinamici che possono coordinare nucleofili attraverso boro del vuoto p-orbitale, Miljanić usato questa caratteristica per sviluppare sensori ibridi composti benzobisoxazole cruciforme 4 e semplice non fluorescente boronico acido additivi B1 e B5 (Figura 4). 11, 12 Questa metodologia funziona come segue: 4 cruciforme e acidi boronico complessi in un complesso transiente 4 · n B1 (o 4 · n B5), la struttura precisa di questo complesso è attualmente sconosciuto, ma sua fluorescenza differisce da quella della cruciforme puro . Se questa soluzione è esposta a Lewis analiti di base, possono sostituire uno o entrambi i gruppi-OH sulla boronico, 13 alterando significativamente le proprietà elettroniche di boro e, a sua volta, la fluorescenza del complesso. L&#39;utilizzo di questo &quot;vicaria sensing&quot; metodologia di rilevamento dei fenoli, ammine organiche e uree, cosìcome di piccoli anioni organici e inorganici, potrebbe essere raggiunto. In questo articolo presentiamo un tutorial sull&#39;uso della diretta e vicaria metodologia di rilevamento in modo rapido qualitativamente distinguere strutturalmente correlate (a) acidi carbossilici (figura 3), (b) acidi bo (Figura 4), ​​e, indirettamente, ( c) ammine organiche (Figura 5). Per illustrare la vasta applicabilità dei protocolli riportati, crucimorfi di Bunz stati usati per rilevare acidi carbossilici, mentre i composti di Miljanić stati impiegati per rivelare acidi boronico, e, tramite un sensore ibrido, piccole ammine organiche. Si presume che questi sensori potrebbero essere facilmente scambiati senza grandi conseguenze per la qualità della discriminazione analita.

<table border="1">
		<tbody>
		 <tr>
			<td>Name of Material/ Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments/Description</td>
		 </tr>
		 <tr>
			<td>Cyclohexane (CH)</td>
			<td>Mallinckrodt</td>
			<td>4878-02</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Chlorobenzene (CB)</td>
			<td>JT Baker</td>
			<td>9179-1</td>
			<td></td>
		 </tr>
		 <tr>
			<td>1,2,4-Trichlorobenzene (TCB)</td>
			<td>Alfa Aesar</td>
			<td>19390</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dichloromethane (DCM) - Miljani&#263;</td>
			<td>Mallinckrodt</td>
			<td>4879-06</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Acetonitrile (AN)</td>
			<td>Mallinckrodt</td>
			<td>2856-10</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Chloroform (CF)</td>
			<td>Mallinckrodt</td>
			<td>4440-19</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dichloromethane (DCM) - Bunz</td>
			<td>Sigma Aldrich</td>
			<td>24233</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Ethyl Acetate (EtOAc)</td>
			<td>Brenntag</td>
			<td>10010447</td>
			<td>Additional distillation</td>
		 </tr>
		 <tr>
			<td>Acetonitrile (AN)</td>
			<td>Sigma Aldrich</td>
			<td>34851</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dimethylformamide (DMF)</td>
			<td>Sigma Aldrich</td>
			<td>38840</td>
			<td></td>
		 </tr>
		 <tr>
			<td>2-Propanol (iPrOH)</td>
			<td>Ruprecht-Karls Universit&auml;t Heidelberg, Zentralbereich Neuenheimer Feld</td>
			<td>69595</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Methanol (MeOH)</td>
			<td>VWR</td>
			<td>20847.295</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Hydroxybenzoic Acid (A1)</td>
			<td>Fluka</td>
			<td>54630</td>
			<td></td>
		 </tr>
		 <tr>
			<td>(4-Hydroxyphenyl)acetic Acid (A2)</td>
			<td>Sigma Aldrich</td>
			<td>H50004</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Ibuprofen (A3)</td>
			<td>ABCR</td>
			<td>AB125950</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Aspirine (A4)</td>
			<td>Sigma Aldrich</td>
			<td>A5376</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Phenylacetic Acid (A5)</td>
			<td>Sigma Aldrich</td>
			<td>P16621</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Chlorophenylacetic Acid (A6)</td>
			<td>Sigma Aldrich</td>
			<td>139262</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Benzoic Acid (A7)</td>
			<td>Merck</td>
			<td>8222571000</td>
			<td></td>
		 </tr>
		 <tr>
			<td>3,5-Dihydroxybenzoic Acid (A8)</td>
			<td>Sigma Aldrich</td>
			<td>D110000</td>
			<td></td>
		 </tr>
		 <tr>
			<td>2,4-Dichlorobenzoic Acid (A9)</td>
			<td>Sigma Aldrich</td>
			<td>139572</td>
			<td></td>
		 </tr>
		 <tr>
			<td>2-Hydroxy-5-iodobenzoic Acid (A10)</td>
			<td>Sigma Aldrich</td>
			<td>I10600</td>
			<td></td>
		 </tr>
		 <tr>
			<td>2,6-Dichlorophenylboronic Acid (B1)</td>
			<td>TCI</td>
			<td>D3357</td>
			<td></td>
		 </tr>
		 <tr>
			<td>3,5-Bis(trifluoromethyl)phenylboronic Acid (B2)</td>
			<td>Sigma Aldrich</td>
			<td>471070</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Mercaptophenylboronic Acid (B3)</td>
			<td>Sigma Aldrich</td>
			<td>524018</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Methoxyphenylboronic Acid (B4)</td>
			<td>TCI</td>
			<td>M1126</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Benzeneboronic Acid (B5)</td>
			<td>Alfa Aesar</td>
			<td>A14257</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Cyclohexylboronic Acid (B6)</td>
			<td>Sigma Aldrich</td>
			<td>556580</td>
			<td></td>
		 </tr>
		 <tr>
			<td>3-Pyridylboronic Acid (B7)</td>
			<td>Sigma Aldrich</td>
			<td>512125</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Nitrophenylboronic Acid (B8)</td>
			<td>Sigma Aldrich</td>
			<td>673854</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Pentafluorophenylboronic Acid (B9)</td>
			<td>Sigma Aldrich</td>
			<td>465097</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Triethylamine (N1)</td>
			<td>Alfa Aesar</td>
			<td>A12646</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Piperidine (N2)</td>
			<td>JT Baker</td>
			<td>2895-05</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Piperazine (N3)</td>
			<td>Aldrich</td>
			<td>P45907</td>
			<td></td>
		 </tr>
		 <tr>
			<td>1,4-Diaminobenzene (N4)</td>
			<td>Alfa Aesar</td>
			<td>A15680</td>
			<td></td>
		 </tr>
		 <tr>
			<td>1,3-Diaminobenzene (N5)</td>
			<td>Eastman</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>1,2-Diaminobenzene (N6)</td>
			<td>TCI</td>
			<td>P0168</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Methoxyaniline (N7)</td>
			<td>Alfa Aesar</td>
			<td>A10946</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Aniline (N8)</td>
			<td>Acros</td>
			<td>22173-2500</td>
			<td></td>
		 </tr>
		 <tr>
			<td>4-Nitroaniline (N9)</td>
			<td>Alfa Aesar</td>
			<td>A10369</td>
			<td></td>
		 </tr>
		 <tr>
			<td>N,N-Diphenylurea (N10)</td>
			<td>Alfa Aesar</td>
			<td>A18720</td>
			<td></td>
		 </tr>
		 <tr>
			<td>N,N-Dimethylurea (N11)</td>
			<td>Alfa Aesar</td>
			<td>B21329</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Urea (N12)</td>
			<td>Mallinckrodt</td>
			<td>8648-04</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Canon EOS 30D (objective EFS 18-55 mm zoom lens)</td>
			<td>Canon</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Canon EOS Rebel T3i (objective EFS 18-55 mm zoom lens)</td>
			<td>Canon</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>FujiFilm FinePix S9000</td>
			<td>Fuji</td>
			<td></td>
			<td></td>
		 </tr>
		</tbody>
 </table>

qualitative identification of carboxylic acids, boronic acids, and amines using cruciform fluorophores

Crucimorfi molecolari sono sistemi a forma di X in cui due assi coniugazione intersecano in un nucleo centrale. Se un asse di queste molecole è sostituito con elettron-donatori, e l&#39;altra con accettori di elettroni, HOMO crucimorfi &#39;localizzerà lungo il ricco di elettroni e LUMO lungo l&#39;asse elettron-poveri. Questo isolamento spaziale della frontiera orbitali molecolari crucimorfi &#39;(FMO) è essenziale per il loro uso come sensori, in quanto vincolanti per l&#39;cruciforme analita invariabilmente cambia il suo gap HOMO-LUMO e le proprietà ottiche associate. Utilizzando questo principio, Bunz e gruppi Miljanić sviluppati 1,4-distyryl-2 ,5-bis (arylethynyl) benzene e benzobisoxazole crucimorfi, rispettivamente, che fungono da sensori fluorescenti per ioni metallici, acidi carbossilici, acidi boronico, fenoli, ammine, e anioni. I colori delle emissioni osservate quando questi cruciforme sono mescolati con gli analiti sono molto sensibili ai dettagli della struttura di analiti e - a causa di crucimorfi &#39;carica-settembrestati eccitati divisero - al solvente in cui viene osservata emissione. Specie strutturalmente strettamente connesse possono essere qualitativamente distinti in più classi di analiti: (a) acidi carbossilici, (b) acidi bo e (c) metalli. Utilizzando un sistema di rilevamento ibrido composto da benzobisoxazole crucimorfi e additivi acidi boronici, siamo stati anche in grado di discernere tra strutturalmente simile: (d) piccoli anioni organici e inorganici, (E), ammine, e (f) fenoli. Il metodo usato per questa distinzione qualitativa è estremamente semplice. Soluzioni diluite (tipicamente 10 -6 M) di crucimorfi in diversi solventi off-the-shelf sono collocati in fiale UV / Vis. Poi, vengono aggiunti analiti di interesse, sia direttamente come solidi o in soluzione concentrata. Cambiamenti di fluorescenza si verificano praticamente istantaneo e possono essere registrati attraverso la fotografia digitale standard utilizzando una fotocamera digitale semi-professionale in una stanza buia. Con minima manipolazione grafica,ritagli di fotografie a colori di emissione rappresentativi possono essere organizzati in pannelli che consentono rapido distinguere ad occhio nudo tra analiti. A fini di quantificazione, i valori Rosso / Verde / Blu possono essere estratti da queste fotografie ed i dati numerici ottenuti possono essere elaborati statisticamente.

Per illustrare le potenzialità di fluorofori cruciformi in rilevamento e discriminare analiti strettamente correlati, tre classi di risultati sono presentati. Prima, 1,4-distyryl-2 ,5-bis (arylethynyl) benzene crucimorfi 1-3 (Figura 1) sono usati per discriminare tra acidi carbossilici strutturalmente correlate A1-A10 mostrati in Figura 3. Poi, benzobisoxazole basata cruciforme 4 (figura 1) è stato utilizzato per analizzare acidi boronico B1-B9 (Figura 4).</st...

Watch this Scientific Journal Video about Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores at JoVE.com

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Fluorofori cruciformi cross-coniugati a base di 1,4-distyryl-2 ,5-bis (arylethynyl) benzene e nuclei benzobisoxazole possono essere usati per identificare qualitativamente diversa Lewis acido e Lewis analiti basici. Questo metodo si basa sulle differenze di colori di emissione degli crucimorfi che si osservano su di analita aggiunta. Specie strutturalmente strettamente connesse possono essere distinti l&#39;uno dall&#39;altro.

Identificazione qualitativa di acidi carbossilici, acidi bo e ammine Utilizzando Fluorofori Cruciform

Molecular cruciforms are X-shaped systems in which two conjugation axes intersect at a central core. If one axis of these molecules is substituted with ...

qualitative-identification-carboxylic-acids-boronic-acids-amines

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Organic Chemistry

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Unit 1

Carboxylic Acids

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15.4K Views.  Ruprecht-Karls-Universität Heidelberg. Fluorofori cruciformi cross-coniugati a base di 1,4-distyryl-2 ,5-bis (arylethynyl) benzene e nuclei benzobisoxazole possono essere usati per identificare qualitativamente diversa Lewis acido e Lewis analiti basici. Questo metodo si basa sulle differenze di colori di emissione degli crucimorfi che si osservano su di analita aggiunta. Specie strutturalmente strettamente connesse possono essere distinti l'uno dall'altro.

Video: Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

The Use of Gas Chromatography to Analyze Compositional Changes of Fatty Acids in Rat Liver Tissue during Pregnancy

Gas chromatography (GC) is a highly sensitive method used to identify and quantify the fatty acid content of lipids from tissues, cells, and plasma/serum, yielding results with high accuracy and high reproducibility. In metabolic and nutrition studies GC allows assessment of changes in fatty acid concentrations following interventions or during changes in physiological state such as pregnancy. Solid phase extraction (SPE) using aminopropyl silica cartridges allows separation of the major lipid classes including triacylglycerols, different phospholipids, and cholesteryl esters (CE). GC combined with SPE was used to analyze the changes in fatty acid composition of the CE fraction in the livers of virgin and pregnant rats that had been fed various high and low fat diets. There are significant diet/pregnancy interaction effects upon the omega-3 and omega-6 fatty acid content of liver CE, indicating that pregnant females have a different response to dietary manipulation than is seen among virgin females.

Pregnancy leads to significant changes to the fatty acid composition of maternal tissues. Lipid profiles can be obtained via gas chromatography to allow identification and quantification of fatty acids in individual lipid classes among rats fed various high and low fat diets during pregnancy.

L&#39;uso di gas cromatografia per analizzare compositivo Variazioni degli acidi grassi nel fegato di ratto tessuto durante la gravidanza

Gas chromatography (GC) is a highly sensitive method used to identify and quantify the fatty acid content of lipids from tissues, cells, and plasma/serum, ...

Ricerca

Chimica

Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy

Colloidal Probe Nanoscopy (CPN), the study of the nano-scale interactive forces between a specifically prepared colloidal probe and any chosen substrate using the Atomic Force Microscope (AFM), can provide key insights into physical interactions present within colloidal systems. Colloidal systems are widely existent in several applications including, pharmaceuticals, foods, paints, paper, soil and minerals, detergents, printing and much more.1-3 Furthermore, colloids can exist in many states such as emulsions, foams and suspensions. Using colloidal probe nanoscopy one can obtain key information on the adhesive properties, binding energies and even gain insight into the physical stability and coagulation kinetics of the colloids present within. Additionally, colloidal probe nanoscopy can be used with biological cells to aid in drug discovery and formulation development. In this paper we describe a method for conducting colloidal probe nanoscopy, discuss key factors that are important to consider during the measurement, and show that both quantitative and qualitative data that can be obtained from such measurements.

Colloidal probe nanoscopy can be used within a variety of fields to gain insight into the physical stability and coagulation kinetics of colloidal systems and aid in drug discovery and formulation sciences using biological systems. The method described within provides a quantitative and qualitative means to study such systems.

Esame quantitativa e qualitativa delle interazioni particella-particella colloidale Uso Probe Nanoscopia

Colloidal Probe Nanoscopy (CPN), the study of the nano-scale interactive forces between a specifically prepared colloidal probe and any chosen substrate ...

Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA)

Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of fossil fuel. PyC is also increasingly produced from the industrial pyrolysis of organic wastes, which yields charred soil amendments (biochar). Moreover, the emergence of nanotechnology may also result in the release of PyC-like compounds to the environment. It is thus a high priority to reliably detect, characterize and quantify these charred materials in order to investigate their environmental properties and to understand their role in the carbon cycle.
Here, we present the benzene polycarboxylic acid (BPCA) method, which allows the simultaneous assessment of PyC&#39;s characteristics, quantity and isotopic composition (13C and 14C) on a molecular level. The method is applicable to a very wide range of environmental sample materials and detects PyC over a broad range of the combustion continuum, i.e., it is sensitive to slightly charred biomass as well as high temperature chars and soot. The BPCA protocol presented here is simple to employ, highly reproducible, as well as easily extendable and modifiable to specific requirements. It thus provides a versatile tool for the investigation of PyC in various disciplines, ranging from archeology and environmental forensics to biochar and carbon cycling research.

Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids BPCA

We present the benzene polycarboxylic acid (BPCA) method for assessing pyrogenic carbon (PyC) in the environment. The compound-specific approach uniquely provides simultaneous information about the characteristics, quantity and isotopic composition (13C and 14C) of PyC.

Caratterizzazione, quantificazione e specifici Compound isotopica analisi di Pirogenica di carbonio utilizzando Benzene Polycarboxylic Acidi (BPCA)

Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as ...

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic acids containing three to six carbons), such as malate and citrate, are critical to the proper functioning of many biological systems, where they function in cellular respiration and can serve as indicators of cell health. In foods, organic acid content can have significant impact on taste, with increased SCCA levels resulting in a sour or &#34;acid&#34; taste. Because of this, methods for the rapid analysis of organic acid levels are of particular interest to the food and beverage industries. Unfortunately, however, most methods used for SCCA quantification are dependent on time-consuming protocols requiring the derivatization of samples with hazardous reagents, followed by costly chromatographic and/or mass spectrometric analyses. This method details an alternate method for the detection and quantification of organic acids from plant material and food samples using free zonal capillary electrophoresis (CZE), sometimes simply referred to as capillary electrophoresis (CE). CZE provides a cost-effective method for measuring SCCAs with a low limit of detection (0.005 mg/ml). This article details the extraction and quantification of SCCAs from plant samples. While the method provided focuses on measurement of SCCAs from coffee beans, the method provided can be applied to multiple plant-based food materials.

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

This article presents a method for the detection and quantification of organic acids from plant material using free zonal capillary electrophoresis. An example of the potential application of this method, determining the effects of a secondary fermentation on organic acid levels in coffee seeds, is provided.

Usando elettroforesi capillare per quantificare Acidi organici da tessuti vegetali: un banco di prova d&#39;esame<em&gt; Coffea arabica</em&gt; Semi

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic ...

Insights into the Interactions of Amino Acids and Peptides with Inorganic Materials Using Single-Molecule Force Spectroscopy

The interactions between proteins or peptides and inorganic materials lead to several interesting processes. For example, combining proteins with minerals leads to the formation of composite materials with unique properties. In addition, the undesirable process of biofouling is initiated by the adsorption of biomolecules, mainly proteins, on surfaces. This organic layer is an adhesion layer for bacteria and allows them to interact with the surface. Understanding the fundamental forces that govern the interactions at the organic-inorganic interface is therefore important for many areas of research and could lead to the design of new materials for optical, mechanical and biomedical applications. This paper demonstrates a single-molecule force spectroscopy technique that utilizes an AFM to measure the adhesion force between either peptides or amino acids and well-defined inorganic surfaces. This technique involves a protocol for attaching the biomolecule to the AFM tip through a covalent flexible linker and single-molecule force spectroscopy measurements by atomic force microscope. In addition, an analysis of these measurements is included.

Here we present a protocol to measure the force of interactions between a well-defined inorganic surface and either peptides or amino acids by single-molecule force spectroscopy measurements using an atomic force microscope (AFM). The information obtained from the measurement is important to better understand the peptide-inorganic material interphase.

Intuizioni le interazioni di aminoacidi e peptidi con materiali inorganici Uso singola molecola Forza Spettroscopia

The interactions between proteins or peptides and inorganic materials lead to several interesting processes. For example, combining proteins with minerals ...

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

Here we demonstrate potentially low cost and green productions of high thermally stable and carboxylated cellulose nanocrystals (CNCs) and nanofibrils (CNF) from bleached eucalyptus pulp (BEP) and unbleached mixed hardwood kraft pulp (UMHP) fibers using highly recyclable dicarboxylic solid acids. Typical operating conditions were acid concentrations of 50 - 70 wt% at 100 &#176;C for 60 min and 120 &#176;C (no boiling at atmospheric pressure) for 120 min, for BEP and UMHP, respectively. The resultant CNCs have a higher thermal degradation temperature than their corresponding feed fibers and carboxylic acid group content from 0.2 - 0.4 mmol/g. The low strength (high pKa of 1.0 - 3.0) of organic acids also resulted in CNCs with both longer lengths of approximately 239 - 336 nm and higher crystallinity than CNCs produced using mineral acids. Cellulose loss to sugar was minimal. Fibrous cellulosic solid residue (FCSR) from the dicarboxylic acid hydrolysis was used to produce carboxylated CNFs through subsequent mechanical fibrillation with low energy input.

Here we demonstrate a novel method for green and sustainable productions of highly thermally stable and carboxylated cellulose nanocrystals (CNC) and nanofibrils (CNF) using highly recyclable solid dicarboxylic acids.

Produzione Verde e basso costo di termicamente stabile e carbossilati cellulosa nanocristalli e Nanofibrils Utilizzando altamente riciclabile bicarbossilici Acidi

Here we demonstrate potentially low cost and green productions of high thermally stable and carboxylated cellulose nanocrystals (CNCs) and nanofibrils ...

Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

Disaccharide nucleosides, which consist of disaccharide and nucleobase moieties, have been known as a valuable group of natural products having multifarious bioactivities. Although chemical O-glycosylation is a commonly beneficial strategy to synthesize disaccharide nucleosides, the preparation of substrates such as glycosyl donors and acceptors requires&#160;tedious protecting&#160;group manipulations and a purification at each synthetic step. Meanwhile, several research groups have reported that boronic and borinic esters serve as a protecting or activating group of carbohydrate derivatives to achieve the regio- and/or stereoselective acylation, alkylation, silylation, and glycosylation. In this article, we demonstrate the procedure for the regioselective O-glycosylation of unprotected ribonucleosides utilizing boronic acid. The esterification of 2&#39;,3&#39;-diol of ribonucleosides with boronic acid makes the temporary protection of diol, and, following O-glycosylation with a glycosyl donor in the presence of p-toluenesulfenyl chloride and silver triflate, permits the regioselective reaction of the 5&#39;-hydroxyl group to afford the disaccharide nucleosides. This method could be applied to various nucleosides, such as guanosine, adenosine, cytidine, uridine, 5-metyluridine, and 5-fluorouridine. This article and the accompanying video represent&#160;useful (visual) information for the O-glycosylation of unprotected nucleosides and their analogs for the synthesis of not only disaccharide nucleosides, but also a variety of biologically relevant derivatives.

Regioselective O-Glycosylation of Nucleosides via the Temporary 2&#039;,3&#039;-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

Here, we present protocols for the synthesis of disaccharide nucleosides by the regioselective O-glycosylation of ribonucleosides via a temporary protection of their 2&#39;,3&#39;-diol moieties utilizing a cyclic boronic ester. This method applies to several unprotected nucleosides such as adenosine, guanosine, cytidine, uridine, 5-methyluridine, and 5-fluorouridine to give corresponding disaccharide nucleosides.

Regioselettiva O- glicosilazione dei nucleosidi tramite il temporaneo 2', 3'-diolo protezione da boronico per la sintesi di disaccaride nucleosidi

Disaccharide nucleosides, which consist of disaccharide and nucleobase moieties, have been known as a valuable group of natural products having ...

Enzymatic Synthesis of Epoxidized Metabolites of Docosahexaenoic, Eicosapentaenoic, and Arachidonic Acids

The epoxidized metabolites of various polyunsaturated fatty acids (PUFAs), termed epoxy fatty acids, have a wide range of roles in human physiology. These metabolites are produced endogenously by the cytochrome P450 class of enzymes. Because of their diverse and potent biological effects, there is considerable interest in studying these metabolites. Determining the unique roles of these metabolites in the body is a difficult task, as the epoxy fatty acids must first be obtained in significant amounts and with high purity. Obtaining compounds from natural sources is often labor intensive, and soluble epoxide hydrolases (sEH) rapidly hydrolyze the metabolites. On the other hand, obtaining these metabolites via chemical reactions is very inefficient, due to the difficulty of obtaining pure regioisomers and enantiomers, low yields, and extensive (and expensive) purification. Here, we present an efficient enzymatic synthesis of 19(S),20(R)- and 16(S),17(R)-epoxydocosapentaenoic acids (EDPs) from DHA via epoxidation with BM3, a bacterial CYP450 enzyme isolated originally from Bacillus megaterium (that is readily expressed in Escherichia coli). Characterization and determination of purity is performed with nuclear magnetic resonance spectroscopy (NMR), high-performance liquid chromatography (HPLC), and mass spectrometry (MS). This procedure illustrates the benefits of enzymatic synthesis of PUFA epoxy metabolites, and is applicable to the epoxidation of other fatty acids, including arachidonic acid (AA) and eicosapentaenoic acid (EPA) to produce the analogous epoxyeicosatrienoic acids (EETs) and epoxyeicosatetraenoic acids (EEQs), respectively.

We present a method useful for large-scale enzymatic synthesis and purification of specific enantiomers and regioisomers of epoxides of arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) with the use of a bacterial cytochrome P450 enzyme (BM3).

Sintesi ezimatica dei metaboliti epossidici degli acidi docosahexaenoici, eicosapentaenoici e aracidonici

The epoxidized metabolites of various polyunsaturated fatty acids (PUFAs), termed epoxy fatty acids, have a wide range of roles in human physiology. These ...

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it efficient in both time and resources and utilizes water as the solvent. 3-Aminocrotononitrile or an appropriate &#945;-cyanoketone is combined with an aryl hydrazine and dissolved in 1 M HCl. The mixture is then heated in a microwave reactor at 150 &#176;C, typically for 10-15 min. The product can be readily obtained by basifying the solution with 10% NaOH and isolating the desired compound with a simple vacuum filtration. The use of water as a solvent in this reaction lends to its ease and utility in production, and this method is easily reproducible with a variety of functional groups. Typical isolated yields range from 70-90%, and reactions can be performed on the milligram to gram scale with little to no change in observed yields. Some of the applications of these molecules and their derivatives include pesticides, anti-malarials, and chemotherapeutics, among many others.

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

1-Aryl-1H-pyrazole-5-amines are prepared from aryl hydrazines combined with either 3-aminocrotononitrile or an &#945;-cyanoketone in a 1 M HCl solution using a microwave reactor. Most reactions are done in 10-15 minutes and pure product can be obtained via vacuum filtration with typical isolated yields of 70-90%.

Preparazione a microonde di 1-Aryl-1H-pyrazole-5-ammine

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it ...

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Methine-bridged conjugated bicyclic aromatic compounds are common constituents of a range of biologically relevant molecules such as porphyrins, dipyrrinones, and pharmaceuticals. Additionally, restricted rotation of these systems often results in highly to moderately fluorescent systems as observed in 3H,5H-dipyrrolo[1,2-c:2',1'-f]pyrimidin-3-ones, xanthoglows, pyrroloindolizinedione analogs, BODIPY analogs, and the phenolic and imidazolinone ring systems of Green Fluorescent Protein (GFP). This manuscript describes an inexpensive and operationally simple method of performing a Claisen-Schmidt condensation to generate a series of fluorescent pH dependent pyrazole/imidazole/isoindolone dipyrrinone analogs. While the methodology illustrates the synthesis of dipyrrinone analogs, it can be translated to produce a wide range of conjugated bicyclic aromatic compounds. The Claisen-Schmidt condensation reaction utilized in this method is limited in scope to nucleophiles and electrophiles that are enolizable under basic conditions (nucleophile component) and non-enolizable aldehydes (electrophile component). Additionally, both the nucleophilic and electrophilic reactants must contain functional groups that will not inadvertently react with hydroxide. Despite these limitations, this methodology offers access to completely novel systems that can be employed as biological or molecular probes.

The Claisen-Schmidt condensation reaction is an important methodology for the generation of methine-bridged conjugated bicyclic aromatic compounds. Through utilizing a base-mediated variant of the aldol reaction, a range of fluorescent and/or biologically relevant molecules can be accessed through a generally inexpensive and operationally simple synthetic approach.