Breza Martin
Department of Physical Chemistry, Slovak Technical University, Radlinskeho 9, SK-81237 Bratislava, Slovakia.
Molecules. 2023 Oct 10;28(20):7019. doi: 10.3390/molecules28207019.
The structures of Ag complexes with dimethyl amino phenyl substituted phthalocyanine [dmaphPcAg] of various charges q and in the two lowest spin states m were optimized using the B3LYP method within the D symmetry group and its subgroups. The most stable reaction intermediate in the supposed photoinitiation reaction is [dmaphPcAg]. Group-theoretical analysis of the optimized structures and of their electron states reveals two symmetry-descent mechanisms. The stable structures of maximal symmetry of complexes [dmaphPcAg], [dmaphPcAg], [dmaphPcAg], and [dmaphPcAg] correspond to the D group as a consequence of the pseudo-Jahn-Teller effect within unstable D structure. Complexes [dmaphPcAg], [dmaphPcAg], [dmaphPcAg], and [dmaphPcAg] with double degenerate electron ground states in D symmetry structures undergo a symmetry descent to stable structures corresponding to maximal D symmetry, not because of a simple Jahn-Teller effect but due to a hidden pseudo-Jahn-Teller effect (strong vibronic interaction between excited electron states). The reduction of the neutral photoinitiator causes symmetry descent to its anionic intermediate because of vibronic interactions that must significantly affect the polymerization reactions.
采用B3LYP方法在D对称群及其子群内，对具有不同电荷q且处于两个最低自旋态m的二甲基氨基苯基取代酞菁银配合物[dmaphPcAg]的结构进行了优化。假定的光引发反应中最稳定的反应中间体是[dmaphPcAg]。对优化结构及其电子态进行群论分析，揭示了两种对称降阶机制。配合物[dmaphPcAg]、[dmaphPcAg]、[dmaphPcAg]和[dmaphPcAg]的最大对称稳定结构由于不稳定的D结构内的赝 Jahn-Teller 效应而对应于D群。在D对称结构中具有双重简并电子基态的配合物[dmaphPcAg]、[dmaphPcAg]、[dmaphPcAg]和[dmaphPcAg]发生对称降阶至对应最大D对称的稳定结构，这不是因为简单的 Jahn-Teller 效应，而是由于隐藏的赝 Jahn-Teller 效应（激发电子态之间的强振动电子相互作用）。中性光引发剂的还原由于振动电子相互作用导致其对称降阶至阴离子中间体，这必然会显著影响聚合反应。
