Thi Hong Hai Le, T. Nguyen, T. Ngo
Nov 16, 2020
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0
Influential Citations
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Citations
Journal
Journal of Fluorescence
Abstract
Starting from eugenol (4-allyl-2-methoxyphenol) three new quinoline derivatives, namely 5-bromo-7-(carboxymethoxy)-6-hydroxy-1-methylquinolin-1-ium-3-sulfonate ( Q2 , C 12 H 10 BrNO 7 S), 5-amino-7-(carboxymethoxy)-6-hydroxyquinolin-1-ium-3-sulfonate ( Q4 , C 11 H 10 N 2 O 7 S) and 7-(carboxymethoxy)-5,6-dihydroxylquinolin-1-ium-3-sulfonate ( Q6 , C 11 H 9 NO 8 ), have been synthesized and crystallised as dihydrate. The best planes through the quinoline ring and the carboxymethoxy substituent is 6.60 (14), 7.28 (6) and 4.73 (7)° for Q2 , Q4 and Q6 , respectively. The crystal packing of Q2 is characterised by O-H…O, π …π and Br …pyridine interactions. The two water molecules bridge three sulphate groups. Infinite chains of Q4 running in the direction [021] are formed by O/N-H …O hydrogen bonds at both ends of the molecule. Parallel chains interact by O/N-H…O hydrogen bonds and π…π and C=O…phenyl stacking. The -NH 2 substituent bridges two sulphate groups, while the two water molecules bridge the other functional groups. The packing of Q6 consists of sheets of molecules interaction through O/N-H…O hydrogen bonds while the two water molecules bridge all function groups present. Parallel sheets interact through π…π and C=O…pyridine stacking. An aqueous solution of Q2 and its precursor 7-(carboxymethoxy)-6-hydroxyquinolin-1-ium-3-sulfonate ( Q ) exhibits fluorescence which is pH dependent. The fluorescence intensity of a 10 μM solution of Q containing Zn 2+ reaches its maximum for a [Zn 2+ ]:[ Q ] ratio of 1:1. The fluorescence properties of Q , Q2, Q4 and Q6 were further investigated by DFT calculation methods.