Influence of the Steric/Electronic Properties of N -Aryl Substituents in Cycloplatinated Guanidinate(1-) Complexes on the Formation of Discrete Pt → Ag Complexes and One-Dimensional Coordination Polymer.

The reactions of cycloplatinated guanidinate(1-) complexes 1 - 6 with AgTFA (TFA = OC(O)CF 3 ) in 1:1 and 1:2 Pt II /Ag I molar ratios afforded complexes containing three types of Pt 2 Ag 2 skeletons ( 7 - 10 , 11 , and 13 ), one 1D CP containing Pt 2 Ag 3 skeleton ( 16 ), and a Pt 2 Ag 4 complex ( 17 ) in 91-95% (method 1), 73-82% (method 2) ( 7 - 10 ), and 54-79% ( 11 , 13 , 16 , and 17 ) yields. The reactions of 11 with 2,6-XylNC (2,6-Xyl = 2,6-Me 2 C 6 H 3 ) and 4-DMAP (4-dimethylaminopyridine) gave a neutral complex 18 and an ionic complex 19 , respectively. Molecular structures of 12 complexes were unambiguously determined by single-crystal X-ray diffraction. Ten complexes contain unprecedented PtAg skeletons and are shown to contain multiple number of dative Pt → Ag bonds supported by the TFA ligand, platinated carbon of the TAG ligand, or both these ligands in conjunction with the Ag-Ag contacts stabilized by argentophilic interaction. Further, the new complexes were characterized by analytical, IR, and multinuclear NMR ( 19 F, 1 H, 13 C{ 1 H}, and 195 Pt) spectroscopies, powder X-ray diffraction, and TGA/DTA. In solution, 9 and 19 exist in more than one form as identified by multinuclear NMR, and this behavior is ascribed to the restricted (N 2 )C-N(H)Ar single-bond rotation of the TAG ligand. The photophysical properties of 9 and 11 are reported.