Luminescent heterotrinuclear complexes with Pt(diimine)(dithiolate) and metal diphosphine as components

Reactions of Pt(diimine)(tdt) (tdt =3,4-toluenedithiolate) with [M-2(dppm)(2)(MeCN)(2)](2+) (M = Cu-I or Ag-I, dppm = bis(diphenylphosphino)methane) gave heterotrinuclear complexes [PtCu2(tdt)(mu-SH)(dppm)(3)](ClO4) (1) and [PtCu2-(diimine)(2)(tdt)(dppm)(2)](ClO4)(2) (diimine = 2,2'-bpyridine (bpy) 2; 4,4'-dimethyl-2,2'-bipyridine (dmbpy) 3; phenanthroline (phen) 4, 5-bromophenanthroline (Brphen) 5) for M = Cu-I, but [PtAg2(tdt)(mu-SH)(dppm)(3)](SbF6) (6) and [PtAg2-(diimine)(tdt)(dppm)(2)](SbF6)(2) (diimine = bpy 7; dmbpy 8; phen 9; Brphen 10) for M = Ag-I. While the complexes [PtAg2(diimine)(tdt)(dPPM)21(SbF6)2 (7-10) result from linkage of Pt(diimine)(tdt) and [M2(dPPM)2(MeCN)2]2+ by tdt sulfur donors, formation of [PtCu2(diimine)(2)(tdt)(dPPM)(2)](ClO4)(2) (2-5) is related to rupture of metal-ligand bonds in the metal components and recombination between the ligands and the metal atoms by self-assembly. The formation of 1 and 6 is involved not only in dissociation and recombination of the metal components, but also in disruption of C-S bonds in the dithiolate (tdt). The dithiolate tdt adopts a chelating and bridging coordination mode in anti conformation for [PtCu2(diimine)(2)(tdt)(dppm)(2)](ClO4)(2) (2-5), whereas there is the syn conformation for other complexes. Compounds 1 and 6 represent sparse examples of mu-SH-bridged heterotrinuclear Pt(II)m(2)(I) complexes, in which Pt-II-M-I centers are bridged by dppm and sulfur donors of tdt, whereas M-I-M-I (M = Cu for 1; Ag for 6) centers are linked by dppm and the mu-SH donor. The P-31 NMR spectra show typical platinum satellites (J(Pt-P) = 1450-1570 Hz) for 1-6 and Ag-P coupling for Pt-II-Ag-I (J(Ag-P) = 350-450 Hz) complexes 6-10. All of the complexes show intense emission in the solid state and in frozen glasses at 77 K. The complexes [PtAg2(diimine)(tdt)(dppm)(2)]-(SbF6)(2) (7-10) also afford emission in fluid acetonitrile solutions at room temperature. Solid-state emission lifetimes at room temperature are in the microsecond range. It is revealed that emission energies of the trinuclear heterometallic complexes [PtAg2(diimine)(tdt)(dPPM)(2)](SbF6)(2) (7-10) exhibit a remarkable blue shift (0.10-0.35 eV) relative to those of the precursor compounds Pt(diimine)(tdt). The crystal structures of 1, 2, 4, 6, 8, and 9 were determined by X-ray crystallography.