DOI: 10.1016/j.molstruc.2006.10.015

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 ¹J_PC and for ¹J_PH. 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.