Addition of 1 equiv of KSCPh3 to [LRNiCl] (LR = {(2,6-iPr2C6H3)NC(R)}2CH, R = Me, tBu) in C6H6 results in the formation of [LRNi(SCPh3)] (1, R = Me; 2, R = tBu) in good yields. Subsequent reduction of 1 and 2 with 2 equiv of KC8, in cold (-25 °C) Et2O, in the presence of 2 equiv of 18-crown-6, results in the formation of “masked” terminal NiII sulfides, [K(18-crown-6)][LRNi(S)] (3, R = Me; 4, R = tBu), also in good yields. An X-ray crystallographic analysis of these complexes suggests that they feature partial multiple bond character in their Ni-S linkages. Addition of N2O to a toluene solution of 4 provides [K(18-crown-6)][LtBuNi(SN=NO)] (6), which features the first example of a thiohyponitrite ([κ2-SN=NO]2-) ligand.

ABSTRACT:The reactivity of the "masked" terminal nickel sulfide complex, [K(18-crown-

The “masked” terminal nickel sulfide [K(18-crown-6)][LtBuNiII(S)] mediates the reduction of N2O by CO, via the thioperoxide complex [K(18-crown-6)][LtBuNiII(η2-SO)].

The "masked" terminal nickel sulfide complexes [K(L)][(L(tBu))Ni(II)(S)] (L(tBu) = {(2,6-(i)Pr2C6H3)NC((t)Bu)}2CH, L = 18-crown-6, 2,2,2-cryptand) activate CS2 to give the trithiocarbonate products [(L(tBu))Ni(II)(S,S:κ2-CS3)](-) or [(S,S:κ2-CS3)Ni(II){S,S:κ2-CS2(L(tBu))}](-), further confirming the nucleophilicity of the sulfide (S(2-)) ligand in these complexes.