Sterics level the rates of proton transfer to [Ni(XPh){PhP(CH2CH2PPh2)2}]+ (X = O, S or Se)

Abstract

Rates of proton transfers between lutH⁺ (lut = 2,6-dimethylpyridine) and [Ni(XPh)(PhP{CH₂CH₂PPh₂}₂)]⁺ (X = O, S or Se) are slow and show little variation (k^O : k^S : k^Se = 1 : 12 : 9). This unusual behaviour is a consequence of sterics affecting the optimal interaction between the reactants prior to proton transfer.