Influence of the crystallization solvent on molecular and supramolecular structures of silver(I) tris(3-phenylpyrazolyl)methane complexes

The compound [{HC(3-Phpz)(3)}Ag](BF4) (pz = pyrazolyl ring) has been prepared and shown to crystallize in four different forms depending on the solvent. Vapor-phase diffusion of diethyl ether into nitromethane solutions of the complex produces two polymorphs, an orthorhombic form (1) and triclinic form (2). Both polymorphs are coordination polymers constructed by a kappa(2)-kappa(1) coordination of the tris(3-Phpz)methane units and have similar, but different, supramolecular structures. In I there are two independent chains linked by C-H(...)pi interactions. In 2 only one type of chain is present, with a different internal structure than in 1. Non-covalent forces, mainly C-H(...)pi interactions, organize the chains into sheets and the sheets into a final 3-D supramolecular structure in the case of 1, while in the case of 2 only a 2-D supramolecular structure forms. In contrast, vapor-phase diffusion of diethyl ether into acetonitrile or acetone solutions produces [{HC(3-Ph-pz)(3)}Ag{(CH3)(2)CO}](BF4) (3) and [{HC(3-Phpz)(3)}-Ag(CH3CN)](BF4) (4). In these compounds, the ligand shows tripodal coordination to a single silver center and coordination of one solvent molecule to the metallic center. Both compounds form 3-D supramolecular structures organized by both C-H(...)pi interactions and weak C-(HF)-F-... hydrogen bonds and in the case of 4 pi-pi stacking. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).