Department of Theoretical Chemistry, School of Biotechnology, Royal Institute of Technology, SE-10691 Stockholm, Sweden.
Phys Chem Chem Phys. 2011 Jan 28;13(4):1290-2. doi: 10.1039/c0cp01014f. Epub 2010 Dec 3.
Based on hybrid QM/MM simulation techniques, we rationalize the spectacular solvatochromic reversal behavior observed for a stilbazolium merocyanine (SM) called Brooker's merocyanine dye. This solvatochromic reversal is attributed to a change in the solute π-electron distribution from zwitterionic to neutral following the change in solvents from polar to non polar. Based on our calculations, we suggest that a polar solvent, like water, with larger relative permittivity is influential enough to bring the change in molecular structure from neutral to zwitterionic. Our results clearly indicate that SM exists in a neutral molecular structure in non polar solvents like trichloromethane and thereby we suggest that self-aggregation of SM may not occur in this solvent.
基于混合量子力学/分子力学模拟技术，我们对布罗克的变色菁染料（一种称为 Brooker's merocyanine dye 的 stilbazolium 甲川菁）观察到的显著溶剂变色反转行为进行了合理化解释。这种溶剂变色反转归因于溶剂从极性变为非极性时，溶质π电子分布从两性离子变为中性。根据我们的计算，我们认为像水这样具有较大介电常数的极性溶剂足以使分子结构从中性变为两性离子。我们的结果清楚地表明，SM 在三氯甲烷等非极性溶剂中以中性分子结构存在，因此我们建议 SM 可能不会在该溶剂中发生自聚集。
