- 作者: 羅世鈞 ; 龔美雲 ; 張元騰 等
- 作者服務機構: 中興大學化學系
- 中文摘要: We used extended Huckel calculations, variable- temperature, homonuclear long-range shift-correlated 2-D/sup 1/H NMR and dynamic NOE measurements to investigate rotational phenomena of substituent phenyl rings on(.eta./sup 5/-cyclopentadienyl)(.eta./ sup 4/- tetraphenylcyclobutadiene)cobalt (1). Two closely related compounds, (.eta./sup 5/-cyclopentadienyl)(.eta./sup 4/-1,3- diphenylcyclobutadiene)cobalt (A) and (.eta./sup 5/- cyclopentadienyl)(.eta./sup 4/-1,2-diphenylcyclobutadiene) cobalt, were prepared. Energy minima appeared at conformations of which the dihedral angles between phenyl and cyclobutadiene rings are about 30.degree. for (1) and 0.degree. for (A) according to extended Huckel calculations. In (1), ortho protons of phenyl rings belong to one set of multiplet in /sup 1/H NMR; meta and para protons belong to the other. It was supported by a long-range coupling 2-D/sup 1/H NMR and NOE experiments. A sharp line due to phenyl rings was observed in the low-temperature /sup 1/H NMR spectrum of (A), which indicates that the five protons are magnetically equivalent at that temperature.
- 英文摘要: --
- 中文關鍵字: Huckel Calculation; Rotational Phenomena; Cyclopentadienyl Complex; Nuclear Magnetic Resonance Spectrometry
- 英文關鍵字: Huckel計算;旋轉現象;環戊二烯基錯合物;核磁共振光譜術