A Highly Delocalized Triplet Carbene, 5-Methylhexa-1,2,4-triene-1,3-diyl: Matrix IR Identification, Structure, and Reactions
作者:Sergey E. Boganov、Valery I. Faustov、Konstantin N. Shavrin、Valentin D. Gvozdev、Vladimir M. Promyslov、Mikhail P. Egorov、Oleg M. Nefedov
DOI:10.1021/ja901508c
日期:2009.10.21
as the HC(4m+1)H-type polyacetylenic carbenes. The carbene readily reacts with molecular oxygen, producing carbonyl oxides, which undergo further transformations typical of this type of compound upon irradiation in the UV-visible region. Two major photolytic rearrangements of 5-methylhexa-1,2,4-triene-1,3-diyl represent reactions characteristic of vinyl carbenes and resulting in the formation of 1-ethynyl-3
在正式卡宾中心同时带有乙烯基和乙炔基的高度离域三线态卡宾的第一个代表 5-methylhexa-1,2,4-triene-1,3-diyl,已在低温 Ar 基质中在紫外线下产生5-乙炔基-3,3-二甲基-3H-吡唑的光解并通过FTIR光谱检测。3H-吡唑向卡宾的转化通过中间体 3-diazo-5-methylhex-4-en-1-yne 分两个阶段进行。根据 DFT PBE/TZ2P 计算,5-methylhexa-1,2,4-triene-1,3-diyl 具有沿五碳链的有效共轭,并显示出与 HC(4m +1)H-型聚炔卡宾。卡宾很容易与分子氧反应,产生羰基氧化物,在紫外-可见光区域照射时,它们会发生这种类型化合物的典型转化。5-methylhexa-1,2,4-triene-1,3-diyl 的两个主要光解重排代表了乙烯基卡宾的反应特征,导致形成 1-ethynyl-3,3-二甲基环丙烯和