An experimental and DFT analysis of coupling constants in [31P(CH3)nH(4−n)]+ systems where n = 0–4 with a note on [14N(C2H5)4]+ and [31P(C2H5)4]+
The experimentally determined coupling constants of phosphonium cations of general formula [P(CH3)nH(4−n)]+ where n = 0–4 have been gathered and those corresponding to measured again. They have been compared with the coupling constants computed at the B3LYP/6-311++G(d,p)//B3LYP//6-311++G(d,p) level. The agreement is highly satisfactory save for 1JPC and for 1JPH. The last problem is probably related to specific solvation through hydrogen bonds. The cases of and were also examined to provide a basis for the fact that β protons show a large coupling constant with 14N than α protons.