One-dimensional coordination polymers with phenyl-carbaborane anions: Ag(I)/4,4'-bipyridine and 2,3-Bis-(2-pyridyl)pyrazine complexes

A series of new silver/4,4'-bipyridine [Ag(I)/bpy] and silver/2,3-bis-(2-pyridyl)pyrazine [Ag(I)/bppz] crystalline complexes with the C-phenyl-carbaborane anion [PhCB 9 H 9 ]- and the halogenated C-phenyl-carbaborane (HPC) anions [PhCB 9 H 8 Br] - , [BrC 6 H 4 CB 11 H 11 ]-, [PhCB 9 H 4 I 5 ] - , and [PhCB 11 H 5 I 6 ] - has been prepared and characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. While {Ag(bppz)[PhCB 9 H 8 Br]} (6) has been isolated as a discrete dimeric complex, all the remaining complexes feature 1D polymeric coordination chains. Among these 1D coordination chains, only [Ag-(bpy)][PhCB9H9](CH3CN) (1) and [Ag2(bppz)3][BrC 6 H 4 CB 11 H 11 ] 2 (CH3CN) (5) exhibit structures where the carbaborane anions act as simple counteranions and thus are not involved directly in the coordination network. In all the other species, significant framework-construction interaction of the silver center with the {BH} or {BI} units of the carbaborane anions is observed. Interestingly, in complex {Ag(bppz)[PhCB 9 H 9 ]} (CH 3 CN) 0.5 (4) the Ag(I) center has an octahedral geometry with two Ag···H-B interactions between the silver atom and phenyl-carbaborane anion. The influence of the carbaborane anions on the structural features of coordination chains is analyzed and discussed, and the preparation of the [NEt 4 ] + salts of the [PhCB 9 H 8 Br]-, [BrC 6 H 4 CB 11 H 11 ] - and [PhCB 9 H 4 I 5 ] - anions is also presented.