Photophysical, dynamic and redox behavior of tris(2,6-diisopropylphenyl)phosphine
作者:René T. Boeré、Alan M. Bond、Steve Cronin、Noel W. Duffy、Paul Hazendonk、Jason D. Masuda、Kyle Pollard、Tracey L. Roemmele、Peter Tran、Yuankui Zhang
DOI:10.1039/b709602j
日期:——
5 in the solid (CP-MAS). Room temperature 1H and 13C spectra reflect D3 symmetry, changing below −30 °C to C3. A variable temperature NMR study provided an activation enthalpy of 49(±1) kJ mol−1 and entropy of 24–27(±5) J mol−1K−1. An energy surface calculation using HF/3-21G theory discovered a single low-energy path describing pyramidal inversion through a transition state that is close to D3 geometry
标题膦(Dipp 3 P)的合成采用芳基 铜试剂及其结构决定 X射线晶体学(R = 2.94%):d(P–C)= 1.852(1)Å,C–P–C = 111.88(5)°。在己烷溶液中,电子光谱显示3个谱带[326(9.3),254(8.7),205(11.4)nm(log | ε |)],并且荧光光谱的斯托克斯位移为129 kJ mol -1。核磁共振:(δ)31 P =溶液中-49.7 ppm,固体中-49.5(CP-MAS)。室温1 H和13 C光谱反映D 3对称性,在−30°C以下变为C 3。一种变温NMR研究提供了49(±1)kJ mol -1的活化焓和24-27(±5)J mol -1 K -1的熵。使用HF / 3-21G理论进行的能表面计算发现了一条低能路径,该路径描述了通过接近D 3几何形状的过渡态进行金字塔反演的过程。计算出的B3LYP / 6-31G(d)平坦化势垒为37