Syntheses and Structures of Mononuclear, Dinuclear and Polynuclear Silver(I) Complexes of 2-Pyrazole-Substituted 1,10-Phenanthroline Ligands

A series of mononuclear, dinuclear and polynuclear silver(I) complexes (1-6) bearing 2-pyrazole-substituted 1,10-phenanthroline derivatives (L-1, L-F(1), L-2) have been synthesized and characterized by H-1 and C-13 NMR, IR spectroscopy, elemental analysis, and single crystal X-ray diffraction. Reaction of L-1 (L-1 = 2-(3,5-dimethylpyrazol-1-yl)-1,10-phenanthroline) with AgClO4 or AgBF4 afforded two dinuclear silver(I) complexes [Ag-2(O-2(CH3CN)(2)] (ClO4)(2) (1) and [Ag-2(L-1)(2)(CH3CN)(2)](BF4)(2) (2), in which two [AgL1(CH3CN)](+) units are linked by Ag center dot center dot center dot Ag interaction (Ag center dot center dot center dot Ag separation: 3.208(2) and 3.248(1) angstrom, respectively). A one-dimensional polymer {[AgL1]BF4)}(infinity) (3) consisting of an infinite center dot center dot center dot Ag center dot center dot center dot Ag center dot center dot center dot Ag center dot center dot center dot chain (Ag center dot center dot center dot Ag separation: 3.059(1) angstrom), as well as a dinuclear complex [Ag-2(ClO4)(2)(L-1)(2)] (4) in which the perchlorate anions instead of solvents are involved in the metal coordination, have also been obtained. The mononuclear complex [Ag(L-F(1))(2)](BF4) (5) was synthesized from L-F(1) (L-F(1) = 2-(3,5-bis(trifluoromethyl)pyrazol-1-yl)-1,10-phenanthroline) and AgBF4, while the dinuclear [Ag-2(BF4)(2)(L-2)(2)] (6) was isolated from L-2 (L-2 = 24N-(3-methyl-5-phenylpyrazole)]-1,10-phenanthroline). The photoluminescence properties of the ligands and complexes 1-6 have been studied both in the solid state and in solution.