Bridge cleavage reactions of late transition-metal dimers with [Ph2P(E)NP(E′)Ph2]- (E = E′ = S or Se; E = O or S, E′ = S or Se)

Reaction of the dinuclear complexes [{Pd(mu-Cl)(L-L)}(2)] (L-L = C9M12N or C12H12N), [{Pt(mu-OMe)-(C8H12OMe)}(2)], [{RuCl(mu-Cl)(eta(6)-p-MeC6H4Pri)}(2)] or [{RhCl(mu-Cl)(eta(5)-C5Me5)}(2)] with K[Ph2P(E)NP(E)Ph-2] (E = S or Se) in thf gave the corresponding bridge cleaved, mononuclear compounds [Pd(L-L){Ph2P(E)NP(E)Ph-2-E,E'}] , [Pt(C8H12OMe){Ph2P(E)NP(E)Ph-2-E,E'}], [RuCl{Ph2P(E)NP(E)Ph-2-E,E'}(eta(6)-p-MeC6H4Pri)] or [Rh(eta(5)-C5Me5)Cl{Ph2P(E)NP(E)Ph-2-E,E'}] in high yields (64-97%). Transmetallation of K[Ph2P(E)NP(E)Ph-2] (E = S or Se) with [{Pd(mu-Cl)(eta(3)-C3H5)}(2)] in a 1 : 1 ratio gave [Pd(eta(3)-C3H5){Ph2P(E)NP(E)Ph-2-E,E'}]. In contrast, reaction of the potassium salt K[Ph2P(O)NP(E)Ph-2] (E = S or Se) with [{Pd(mu-Cl)(eta(3)-C3H5)}(2)] under analogous conditions gave instead the dimeric species [{Pd(eta(3)-C3H5)[Ph2P(O)NP(E)Ph-2-E]}(2)]. All new compounds have been characterised by a combination of multinuclear NMR [H-1, P-31-{H-1}, Pt-195-{H-1}] and IR spectroscopy, elemental analyses and in four cases by single crystal X-ray crystallography. The six-membered ME2P2N metallacycles [Pd(C9H12N){Ph2P(Se)NP(Se)Ph-2-Se,Se'}], [Pt(C8H12OMe){Ph2P(S)NP(S)Ph-2-S,S')] and [Pd(eta(3)-C3H5){Ph2P-(S)NP(S)Ph-2-S,S'}] all adopt pseudo-boat conformations. In contrast [{Pd(eta(3)-C3H5)[Ph2P(O)NP(Se)Ph-2-Se]}(2)] is binuclear with a central four-membered Pd2Se2 core and two pendant P(O)Ph-2 moieties. The synthesis, characterisation and preliminary complexation studies of a new potassium salt, K[Ph2P(S)NP(Se)Ph-2], prepared by deprotonation of Ph2P(S)NHP(Se)Ph-2 with KOBut are also described.