Coupling of platinated triguanides with platinum-activated nitriles as a novel strategy for generation of dimetallic systemsElectronic supplementary information (ESI) available: Detailed crystallographic data (Tables S1-S5), IR spectra of 2a,b, 3a,b, and 6a,b (Fig. S1-S7), as well as tables with calculated total energies, enthalpies, Gibbs free energies, and entropies in the gas phase and CHCl3 solution (E, H, G, S), Gibbs free energies of solvation ΔGsolv for all studied species (Table S6); tot

One of two Pt IV -activated propanenitriles in trans -[PtCl 4 (EtCN) 2 ] is involved in platinum( iv )-mediated nitrile-imine coupling with the platinum( ii )-based metallacycles [PtCl 2 { N H&z.dbd;C(NR 2 )N(Ph)C(&z.dbd;NH)N(Ph)C(NR 2 )&z.dbd; N H}] [R 2 = Me 2 ( 1a ), C 5 H 10 ( 1b )] yielding diplatinum products, whose structures depend on molar ratios between the reactants. At a 1 : 1 ratio, the mixed-valence platinum( ii )/platinum( iv ) species [PtCl 4 { N H&z.dbd;C(NR 2 )N(Ph)C{&z.dbd;[(N(Et)C&z.dbd; N H)PtCl 2 (EtCN)]}N(Ph)C(NR 2 )&z.dbd; N H}] [R 2 = Me 2 ( 2a ), (CH 2 ) 5 ( 2b )] were generated, whereas at a 1 : 2 ratio the dinuclear platinum( ii )/platinum( ii ) complexes [PtCl 2 { N H&z.dbd;C(NR 2 )N(Ph)C{&z.dbd;[(N(Et)C&z.dbd; N H)PtCl 2 (EtCN)]}N(Ph)C(NR 2 )&z.dbd; N H}] [R 2 = Me 2 ( 3a ), (CH 2 ) 5 ( 3b )] were obtained. In contrast to the nitrile-imine coupling observed for the platinum( iv ) dinitrile complex, the reaction between the platinum( ii ) congener trans -[PtCl 2 (EtCN) 2 ] and any one of 1a,b gives exclusively the substituted dimetallic platinum( ii )/platinum( ii ) products [PtCl 2 { N H&z.dbd;C(NR 2 )N(Ph)C{&z.dbd;[( N H)PtCl 2 (EtCN)]}N(Ph)C(NR 2 )&z.dbd; N H}] [R 2 = Me 2 ( 6a ), (CH 2 ) 5 ( 6b )] featuring platinum-containing guanidine 1 as one of the ligands. Complexes 2a,b , 3a,b , and 6a,b were characterized by elemental analyses (C, H, N), HRESI-MS, IR, 1 H NMR spectroscopy, and DTA/TG. The molecular and crystal structure of 2a ·2CDCl 3 was additionally studied by single-crystal X-ray diffraction. Complexes 2a,b undergo further redox transformation in solutions, and single crystals of [PtCl 2 { N H&z.dbd;C(NMe 2 )N(Ph)C{&z.dbd;[(N(Et)C&z.dbd; N H)PtCl 2 (MeCN)]}N(Ph)C(NMe 2 )&z.dbd; N H}]·2CH 2 Cl 2 ( 3′a ·2CH 2 Cl 2 ) were obtained from 2a in a CH 2 Cl 2 -MeCN-C 2 H 4 Cl 2 mixture and studied by X-ray crystallography. The driving forces for the generation of diplatinum products 2 and 3 were elucidated based on a quantum-chemical study. Intermolecular ligand-ligand coupling as a novel approach to the construction of dimetallic systems.