Amine-functionalised aminophosphines: synthesis, reversible co-ordination to platinum and use in heteronuclear dimer formation

Amine functionalised aminophosphines Ph2PN(R)CH2CH2NMe2 (R = H L-1 or Me L- 2) were prepared from the reaction of PPh2Cl with NHRCH2CH2NMe2 in the pres ence of the base n-butyllithium (L-1) or triethylamine (L-2). Reaction of t wo equivalents of L-1,L-2 with [PtCl2(cod)] gave the complexes cis-[PtCl2L2 ] (L = L-1 1 or L-2 2), which were shown to be fluxional with one of the am ine groups reversibly co-ordinating to displace a chloride. Removal of a ch loride in 1 by metathesis gave cis-[PtCl(L-1-P)(L-1-P,N)]PF6 3 which was no t fluxional on the NMR timescale. Reaction of one equivalent of L-2 with [P tCl2(cod)] gave the complex cis-[PtCl2(L-2-P,N)] 4 in which L-2 is acting a s a bidentate ligand. The reaction of L-2 with [{Pt(dmba)(mu-Cl)}(2)] (Hdmb a = N,N-dimethylbenzylamine) gave [Pt(dmba)Cl(L-2)] 5, which exists as a mi xture of the two geometric isomers. Reaction of 5 with TlPF6 gave [Pt(dmba) (L-2-P,N)]-PF6 6 as a single isomer in which the phosphorus atom is co-ordi nated trans to the N,N-dimethylbenzylamine nitrogen atom. Complex 2 reacts with CoCl2. 6H(2)O and ZnCl2 to give cis-[(L-2-P,N)ClPt(mu-L-2)MCl3] (M = C o 7 or Zn 8). The zwitterionic structure of 7 was confirmed by a single-cry stal X-ray analysis, which showed no metal-metal interaction between the pl atinum and cobalt centres.