New stable colored complex of Al
<sup>3+</sup>
with 1',3',3'‐trimethylspiro[2
<i>H</i>
‐1‐benzopyran‐2,2'‐indoline] (BIPS)
作者:Peter P. Levin、Nikolay E. Belikov、Irina I. Levina、Alexander S. Tatikolov、Andrey A. Khodonov、Igor V. Khudyakov
DOI:10.1002/poc.4012
日期:2019.12
Ultraviolet‐visible (UV‐vis) absorption, flash photolysis, and 1H and 13C NMR spectroscopy were used to investigate the mechanism of formation and structure of complexes in the 1',3',3'‐trimethylspiro[2H‐1‐benzopyran‐2,2'‐indoline] (SP, also well known as BIPS) with Al3+ (inorganic salts) in ethanol (EtOH), methanol (MeOH), and in aqueous MeOH solutions. A labile (equilibrium constants ≤ 5000 M−1)
使用紫外可见(UV-vis)吸收,快速光解以及1 H和13 C NMR光谱研究了1',3',3'-三甲基螺[2 H -1]中复合物的形成和结构机理。[苯并吡喃-2,2'-二氢吲哚](SP,也称为BIPS)与Al 3+(无机盐)在乙醇(EtOH),甲醇(MeOH)和MeOH水溶液中的混合。在存在过量的Al 3+的情况下,迅速出现了SP和Al 3+的不稳定(平衡常数≤5000 M -1)复合物,在紫外可见光谱中具有宽吸收带,λmax = 380 nm 。Al 3+之间缓慢形成稳定的络合物(SC)在保持这两种化合物的溶液在恒定浓度比[Al 3+ ]≥[SP] / 2的条件下,观察到两种在吸收峰处λmax = 430 nm具有强烈吸收带的SP的花青(MC)形式在黑暗中。这种SC形成的速率常数接近于在黑暗中SP转化为MC的相应速率常数(取决于溶剂,为5.0×10 -5 -1×10 -3 s -1)。SC在可见光(λ>