Phosphorus-31 and carbon-13 nuclear magnetic resonance studies of unsymmetrical tetra-alkyldiphosphanes R1R2PPMe2 and R1R2PPEt2
作者:Ahmed A. M. Ali、Robin K. Harris
DOI:10.1039/dt9880002775
日期:——
A series of unsymmetrical tetra-alkyldiphosphanes of general formulae R1R2PPMe2 and R1R2PPEt2(with R1, R2= Me, Et, Pri, But) have been obtained by scrambling reactions between the corresponding symmetrical diphosphanes in CH2Cl2 solution and have been studied by n.m.r. spectroscopy in situ. Values of 31P and 13C chemical shifts, together with (P,P) and (P,C) coupling constants, are reported and discussed
一系列通式不对称四- alkyldiphosphanes的[R 1 - [R 2 PPME 2和R 1 - [R 2 PPET 2(其中R 1,R 2 =甲基,乙基,镨我,卜吨)已经由相应之间加扰反应得到在CH 2 Cl 2溶液中对称的二膦,并进行了核磁共振光谱的原位研究。的值31 P和13关于取代基效应和构象,报道并讨论了C化学位移以及(P,P)和(P,C)偶合常数。参数1 J PC + 2 J PC被证明是首选旋转异构体的良好预测指标,并且得出结论,1 J PC和2 J PC的符号必须相反。