Synthesis and multinuclear NMR characterizations of some [3.3]diselena- and [4.4]tetraselenacyclophanes.
作者:Massoud Hojjatie、Subramaniam Muralidharan、Henry Freiser
DOI:10.1016/s0040-4020(01)80024-7
日期:1989.1
and unsymmetrical bis-selenacyclophanes were prepared and characterized by multinuclear (1H, 13C1H} and 77Se1H}) NMR. The symmetrical cyclophanes of phenyl, furyl, pyridyl and thiophenyl appear to exist in predominantly syn conformation in solution at room temperature. VT-1H NMR of some cyclophanes indicate that the equilibrium between the syn conformers which differ in the disposition of the bridge
制备了几个对称和不对称的双硒代硒环,并通过多核(1 H,13 C 1 H}和77 Se 1 H})NMR进行了表征。苯基,呋喃基,吡啶基和噻吩基的对称环烷似乎在室温下主要以顺式构象存在。一些环烷的VT- 1 H NMR表明,在低温下,桥硒分布不同的顺式构象异构体之间的平衡(相对于镜面对称,不对称于反转中心)是可以减慢的。有趣的13 C 1在含有2,2′-联苯,吡啶和呋喃的不对称环烷中观察到H}位移。的77硒 1 H}化学位移似乎与对环芳的腔的尺寸。