The addition reaction of hydroxide or ethoxide ion with benzindolium heptamethine cyanine dyes
The addition reaction of hydroxide or ethoxide ion with benzindolium heptamethine cyanine dyes
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DOI：
10.1016/s0143-7208(00)00046-2
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发表时间：
2000-09-01
影响因子：
4.5
通讯作者：
Patonay, G
中科院分区：
文献类型：
--
作者：
Strekowski, L;Mason, JC;Patonay, G
本文研究了苯并[c]吲哚鎓或3，3-二甲基-1H-苯并[e]吲哚鎓亚基与相应的近红外七甲川花青的C2原子之间的亲核加成反应。一个重要的发现是，在这些染料中的氯取代基的有效的S（RN）1替换在（i）氢氧根和乙氧基离子的反应中被完全抑制，这两者都是差的单电子供体，以及（ii）在含水醇中进行，含水醇是一种不促进单电子转移的介质。通过元素分析、H-1 NMR和C-13 NMR对所产生的加合物进行分离和表征。在用弱酸（包括硅胶）处理相应的加合物后，NIR吸收母体染料定量再生。(C)2000爱思唯尔科技有限公司版权所有。
This paper pertains to a nucleophilic addition reaction at the C2 atom of a benz[c]indolium or 3,3-dimethyl-1H-benz[e]indolium subunit of the corresponding near-infrared heptamethine cyanine that contains a chlorine atom at the central meso position of the chromophore. An important finding is that the efficient S(RN)1 replacement of the chloro substituent in such dyes is completely suppressed in the reactions (i) of hydroxide and ethoxide ions, both of which are poor single electron donors and (ii) conducted in aqueous alcohol, a medium that does not promote single electron transfer. The adducts produced were isolated and characterized by elemental analysis, H-1 NMR, and C-13 NMR. The NIR-absorbing parent dye is regenerated quantitatively upon treatment of the corresponding adduct with a weak acid, including silica gel. (C) 2000 Elsevier Science Ltd. All rights reserved.