Synthesis, Structure, and Photoluminescence of Zinc(II) and Silver(I) Complexes with 2-(3,5-Dimethyl-1H-pyrazol-1-yl)-4,6-Diphenylpyrimidine

The complexes [AgL2]PF6 (I) and [ZnLCl2] (II) (L = 2-(3,5-dimethyl-1H-pyrazol-1-yl)-4,6-diphenylpyrimidine) were prepared by the reaction of zinc(II) chloride or silver(I) hexafluorophosphate with L (M : L molar ratio of 1 : 1 or 1 : 2) in organic solvents. The structure of the complexes was determined by X-ray diffraction (CIF file CCDC no. 2118498). In both complexes, L is coordinated in the bidentate chelating manner; the coordination unit is a distorted tetrahedron. The coordination unit of II is formed by one coordinated molecule L and two chloride ions (ZnN2Cl2); in the case of silver(I), there are two molecules L (AgN4). The photoluminescent properties of compounds I and II in the solid state were studied. The compound II shows fluorescence (1.3, 11 ns) in the blue spectral range (λmax = 378 nm; quantum yield of 7.8%). The maximum at 530 nm in the photoluminescence spectrum of I is red-shifted by ~140–160 nm relative to the emission maxima of L and II. The complex I shows white light emission (1.6, 11 ns, quantum yield of 5.5%), which is due to intraligand transitions perturbed by the coordination of L to the silver atom. The photostability of I was studied at 300 and 80 K.