Coordination chemistry of [CH2(PPh2) (P(Y)R2)] and [CH(PPh2)(P(Y)R2)]−, Y = S or Se, R = Ph or tBu: rhodium, iridium and ruthenium complexes; 13C 31P, and 77 Se NMR studies; and the crystal and molecular structures of [Ir(cod)CH2(PPh2)(P(S)tBu2)-P,S]BF4 · CHCl3, [Rh(cod)CH2(PPh2)(P(S)tBu2)-P,SClO4 · CH2Cl2 [Rh(cod)CH(PPh2) (P(S)Ph2)-P,S] and [RuCl2(p-cymene)CH2(PPh2)(P(S) Ph2) -P] · CH2Cl2

Abstract

Reactions of the chloro-bridged complexes, [M2Cl2(cod)2], M  Ir or Rh, COD  cyclooctadiene, with CH2(PPh2)(P(Y)R2), Y  S or Se, R  Ph or tBu, provide a synthetic route to the cations, [M(cod)(CH2(PPh2)(P(Y)R2)-P,S]+, which are isolated as fluoroborate or perchlorate salts. Treatment of these products with sodium hydride results in facile deprotonation to the neutral complexes, [M(cod)CH(PPh2)(P(Y)Ph2)-P,S)], and when Y  S, the neutral complexes are also accessible via reactions of [M2Cl2(cod)2] with Li[CH(PPh2)(P(S)R2)]. Reactions of the cations, [M(cod)CH2(PPh2)(P(S)tBu2)-P,S)]+ with other ligands, Lg  (CO)2, (CNtBu)2, or bis(diphenylphosphino)methane (dppm), result in displacement of cod to form [M(Lg)(CH2(PPh2)(P(S)tBu2)-P,S]+. Ruthenium complexes of CH2(PPh2)(P(S)Ph2) are accessiblevia similar bridge cleavage reactions using [Ru2Cl4L2], L  benzene or p-cymene. These complexes are characterized by complete 13C, 31P, and 77Se nuclear magnetic resonance (NMR) studies and by four crystal structure determinations. The complexes [Ir(cod)(CH2(PPh2)(P(S)tBu2)-P,S]BF4·CHCl3 (1), [Rh(cod)(CH2(PPh2)(P(S)tBu2)-P,S]ClO4·CH2Cl2 (2), [Rh(cod)(CH(PPh2)(P(S)Ph2-P,S] (3) and [RuCl2(p-cymene)(CH2(PPh2)(P(S)Ph2)-P]· CH2Cl2 (4) crystallize in the P (No. 2) space group (Z  2) with respective unit cells: a = 12.307(7) Å, b = 14.743(8) Å, c = 10.877(6) Å, α =74.42(5)°, β = 107.65(6)°, γ = 105.47(5)°; a = 12.163(1) Å, b = 14.56(1) Å, c = 10.560(1) Å, α = 77.69(1)°, β = 74.54(1)°, γ = 77.01(1)°; a = 10.650(4) Å, b = 13.327(4) Å, c = 10.419(3) Å, α = 90.60(3)°, β = 102.64(3)°, γ = 83.15(3)°; a = 11.217(2) Å, b 17.124(3) Å, c = 10.412(2) Å, α = 90.58(1)°, β = 112.29(2)°, γ = 97.53(2)°. Complexes 1–3 all contain bidentate P,S-bonded ligands occupying two coordination positions of an approximately square planar metal centre. In each case, the coordination is completed by two double bonds of a cod ligand. In contrast, complex 4 contains a monodentate P-bonded ligand.