Molybdenum(0), ruthenium(II), palladium(II), platinum(II), copper(I) and gold(I) complexes of a new methoxy functionalised his(phosphino)amine: synthesis and structure

The synthesis, and characterisation, of a new functionalised bis(phosphino)amine Ph2PN(o-C6H4OMe)PPh2 1 from o-H2NC6H4OMe and 2 equiv. of Ph2PCl in diethyl ether at 0 degrees C is reported. Oxidation of 1 with either aqueous H2O2, elemental S-8 or grey Se affords the phosphorus(V) compounds Ph2P(E)N(o-C6H4OMe)P(E)Ph-2 (E = O 2; S 3 or Se 4). Partial oxidation of 1 with 1 equiv. of S-8 in n-hexane affords the mixed P(III)/P(V) species Ph2P(S)N(o-C6H4OMe)PPh2 5 in addition to small amounts of 3. Reaction of 1 (or 5) with [MX2(cod)] (M = Pd, Pt; X = Cl or CH3; cod = cycloocta-1,5-diene) affords either cis-[MX2{Ph2PN(o-C6H4OMe)PPh2}] (M = Pd, X = Cl 6; M = Pt, X = Cl 7; M = Pt, X = CH3 8) or the neutral five-membered chelate complexes [MCl2{Ph2P(S)N(o-C6H4OMe)PPh2}] (M = Pd 9, M = Pt 10) in which P,P- or P,S-chelation respectively was observed. Likewise reaction of [Mo(CO)(4)(nbd)] (nbd = norbornadiene) or [Cu(MeCN)(4)]PF6 with 1 gave cis-[Mo(CO)(4){Ph2PN(o-C6H4OMe)PPh2}] 11 or [Cu{Ph2PN(o-C6H4OMe)PPh2}(2)]PF6 12. Chloro-bridge cleavage and arene elimination of [{RuCl2(p-cym)}(2)] (p-cym = p-cymene) with 1 (1 : 2 metal : ligand ratio) affords, in good yield, the octahedral bis chelate ruthenium(II) complex trans-[RuCl2{Ph2PN(o-C6H4OMe)PPh2}(2)] 13. In contrast, reaction of 1 with two equiv. of [AuCl(tht)] (tht = tetrahydrothiophene) gave the dinuclear complex [(ClAu)Ph2PN(o-C6H4OMe)PPh2(AuCl)] 14 in which the bis(phosphino)amine P,P-bridges two {AuCl} metal fragments. All new compounds have been characterised by a combination of multinuclear NMR [H-1, P-31{H-1} and Pt-195{H-1}], IR spectroscopy and elemental analyses. The molecular structures of six representative examples have been determined by single-crystal X-ray crystallography.