Mixed ligand complexes of silver(i) supported by highly fluorinated pyrazolates, and chelating and bridging N-heterocycles†
Abstract
The chemistry of trinuclear silver(I) pyrazolates with aromatic, bidentate N-heterocycles, 1,10-phenanthroline, 4,6-dimethylpyrimidine, 4,7-phenanthroline, benzo[c]cinnoline, and 4-(2-pyridyl)pyrimidine are presented. Results presented here show the effects of the donor nitrogen lone-pair orientations of the N-heterocycles on the product structures. The chelating ligand, 1,10-phenanthroline with {[3,5-(CF3)2Pz]Ag}3, {[4-Cl-3,5-(CF3)2Pz]Ag}3 and {[4-Br-3,5-(CF3)2Pz]Ag}3 produced tetranuclear species, that exhibited blue luminescence under UV light. 4,6-dimethylpyrimidine and 4,7-phenanthroline that have nitrogen lone pairs in a non-chelating arrangement produced polymeric, mixed ligand silver pyrazolate complexes when treated with {[3,5-(CF3)2Pz]Ag}3. The reaction of {[3,5-(CF3)2Pz]Ag}3 with benzo[c]cinnoline did not lead to the breakup of the precursor Ag3N6 core, but resulted in a trinuclear silver complex with two- and three-coordinate silver centers. The reaction between 4-(2-pyridyl)pyrimidine and {[3,5-(CF3)2Pz]Ag}3 generated a coordination polymer featuring saddle-shaped {[3,5-(CF3)2Pz]Ag}4 units. Most of these complexes show intermolecular π-stacking and argentophilic contacts. The fluorinated pyrazolate serves as a bridging ligand in all the silver complexes.