Synthesis and enantiomeric recognition studies of triazine-based chiral fluorescent compounds

Abstract

In this study novel fluorescence active, two triazine based thiazole derivatives,  (2R,2'R)-2,4,6-triamine-N²-[2-(4-benzothiazolyl)phenyl]-N⁴,N⁶-[di(butan-1-ol)]-1,3,5-triazine and (1S,1'S,2R,2'R)-2,4,6-triamine-N²-[2-(4-benzothiazolyl)phenyl]-N⁴,N⁶-[di(1,2-diphenylethanol)]-1,3,5-triazine with chiral aminoalcohol groups were synthesized conveniently. Their enantiomeric recognition abilities toward the enantiomers of carboxylic acids such as mandelic acid and 2-chloromandelic acid were examined in DMSO/H₂O (30:70) system using fluorescence spectroscopy. It was observed that DMSO solutions of chiral selectors showed no fluorescence emission while the emission increased 38 and 43 fold in 95% H₂O for butan-1-ol and diphenylethanol derivatives, respectively similar with the aggregation-induced emission (AIE) characterized compounds. In the light of the experiment results, it was determined that the R-isomers of carboxylic acids formed more favourable complexes with the chiral selectors when compared to S-isomers.

Keywords

• Chiral recognition,fluorescence,triazine,thiazole,hydrogen bonding,carboxylic acid,aggregation-induced emission

Triazin bazlı kiral floresans bileşiklerin sentezi ve enantiyomerik tanınma çalışmaları

Abstract

Bu çalışmada yeni floresans aktif, iki adet triazin bazlı tiyazol türevleri, (2R,2'R)-2,4,6-triamin-N²-[2-(4-benzotiyazolil)fenil]-N⁴,N⁶-[di(bütan-1-ol)]-1,3,5-triazin ve (1S,1'S, 2R,2'R)-2,4,6-triamin-N²-[2-(4-benzotiyazolil)fenil]-N⁴,N⁶-[di(1,2-difenil etanol)]-1,3,5-triazin uygun şekilde sentezlendi. İlgili bileşiklerin, mandelik asit ve 2-kloromandelik asit gibi karboksilik asit enantiyomerlerine karşı enantiyomerik tanıma yetenekleri, DMSO/H₂O (30:70) sisteminde floresans spektroskopisi aracılığıyla incelendi. Kiral seçicilerin DMSO çözeltileri floresans emisyonu göstermez iken, %95 su yüzdesine çıkıldığında, agregasyona bağlı emisyon karakterli bileşiklere benzer olarak emisyonun sırasıyla bütan-1-ol ve difeniletanol türevleri için 38 ve 43 kat arttığı gözlemlendi. Deney sonuçları ışığında, karboksilik asitlerin R-izomerlerinin, S-izomerleri ile karşılaştırıldığında kiral seçiciler ile daha uygun kompleksler oluşturduğu saptandı. 

Keywords

• Kiral tanınma,floresans,triazin,tiyazol,hidrojen bağı,karboksilik asit,kümelenmeye dayalı emisyon

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