Synthesis and coordination chemistry of the new unsymmetrical ligand Ph2PCH2NHC6H4PPh2

Article abstract of DOI:10.1002/1099-0682(200207)2002:7<1635::AID-EJIC1635>3.0.CO;2-B

Condensation of Ph₂PCH₂OH with 2-(diphenylphosphanyl)-aniline in toluene gave the new unsymmetrical ligand Ph₂PCH₂NHC₆H₄PPh₂ (1) in good yield. Oxidation of 1 with H₂O₂ or elemental sulfur led to the oxidised products Ph₂P(O)CH₂NHC₆H₄P(O) Ph₂ (2) and Ph₂P(S)CH₂NHC₆H₄P(S) Ph₂ (3). The new ligand 1 demonstrates three distinct modes of coordination. Reaction of compound 1 with [MX₂(cod)] (M = Pd, Pt; X = Cl, Br, Me) or [Mo(CO)₄(pip)₂] gave the chelate complexes [PdCl₂(Ph₂PCH₂NHC₆ H₄PPh₂-P_X,P_A)] (4), [PdBr₂(Ph₂PCH₂NHC₆ H₄PPh₂-P_X,P_A)] (5), [PtCl₂(Ph₂PCH₂NHC₆ H₄PPh₂-P_X,P_A)] (6), [PtMe₂(Ph₂PCH₂NHC₆ H₄PPh₂-P_X,P_A)] (7) and [Mo(CO)₄(Ph₂PCH₂NHC₆ H₄PPh₂-P_X,P_A)] (8). Coordination of 1 with [{RuCl(μCl)(η³:η³-C₁₀ H₁₆)}2] or [{RhCl(μ-Cl)(η⁵-C₅Me₅)}₂] gave the monodentate complexes [RuCl₂(η³:η³-C₁₀ H₁₆)(Ph₂PCH₂NHC₆ H₄PPh₂-P_X)] (9) and [RhCl₂(η⁵-C₅Me₅) (Ph₂PCH₂NHC₆H₄ PPh₂-P_X)] (10). Reaction of 1 with [{IrCl(μ-Cl)(η⁵C₅Me₅)}2] led to a mixture from which the monodentate complex [IrCl₂(η⁵-C₅Me₅) (Ph₂PCH₂NHC₆H₄ PPh₂-P_X)] (11) and the chelate cationic complex [IrCl(η⁵-C₅Me₅) (Ph₂PCH₂NHC₆H₄ PPh₂-P_X,P_A)][Cl] (12) were separated. Abstraction of the chloride ligands from complexes 9 and 10 with AgClO₄ gave the cationic chelate complexes [RuCl(η³:η³-C₁₀H₁₆) (Ph₂PCH₂NHC₆H₄ PPh₂-P_X,P_A)][ClO₄] (13) and [RhCl(η⁵-C₅Me₅)(Ph₂ PCH₂NHC₆H₄PPh₂-P_X, P_A][ClO₄] (14). Compound 1 also functions as a bridging ligand when reacted with two molar equivalents of [AuCl(tht)] or one molar equivalent of [{RhCl(μ-Cl)(η⁵-C₅Me₅)}₂] to give the bimetallic complexes [Ph₂P{AuCl}CH₂NHC₆H₄ PPh₂{AuCl}] (15) and [{RhCl₂(η⁵-C₅ Me₅)}₂(Ph₂PCH₂NHC₆ H₄PPh₂)] (16). The dioxidised compounds 2 and 3 and several typical complexes 8, 9, 11 and 14 were structurally characterised by X-ray diffraction. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.