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)
Abstract
Reaction of the dinuclear complexes [{Pd(µ-Cl)(L–L)}2] (L–L = C9H12N or C12H12N), [{Pt(µ-OMe)(C8H12OMe)}2], [{RuCl(µ-Cl)(η6-p-MeC6H4Pri)}2] or [{RhCl(µ-Cl)(η5-C5Me5)}2] with K[Ph2P(E)NP(E)Ph2] (E = S or Se) in thf gave the corresponding bridge cleaved, mononuclear compounds [Pd(L–L){Ph2P(E)NP(E)Ph2-E,E′}], [Pt(C8H12OMe){Ph2P(E)NP(E)Ph2-E,E′}], [RuCl{Ph2P(E)NP(E)Ph2-E,E′}(η6-p-MeC6H4Pri)] or [Rh(η5-C5Me5)Cl{Ph2P(E)NP(E)Ph2-E,E′}] in high yields (64–97%). Transmetallation of K[Ph2P(E)NP(E)Ph2] (E = S or Se) with [{Pd(µ-Cl)(η3-C3H5)}2] in a 1∶1 ratio gave [Pd(η3-C3H5){Ph2P(E)NP(E)Ph2-E,E′}]. In contrast, reaction of the potassium salt K[Ph2P(O)NP(E)Ph2] (E = S or Se) with [{Pd(µ-Cl)(η3-C3H5)}2] under analogous conditions gave instead the dimeric species [{Pd(η3-C3H5)[Ph2P(O)NP(E)Ph2-E]}2]. All new compounds have been characterised by a combination of multinuclear NMR [1H, 31P-{1H}, 195Pt-{1H}] 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)Ph2-Se,Se′}], [Pt(C8H12OMe){Ph2P(S)NP(S)Ph2-S,S′}] and [Pd(η3-C3H5){Ph2P(S)NP(S)Ph2-S,S′}] all adopt pseudo-boat conformations. In contrast [{Pd(η3-C3H5)[Ph2P(O)NP(Se)Ph2-Se]}2] is binuclear with a central four-membered Pd2Se2 core and two pendant P(O)Ph2 moieties. The synthesis, characterisation and preliminary complexation studies of a new potassium salt, K[Ph2P(S)NP(Se)Ph2], prepared by deprotonation of Ph2P(S)NHP(Se)Ph2 with KOBut are also described.