Abstract

The crystal structure of the title rhenium(I) complex [ReCl(C7H5BrN4)(CO)(3)]center dot C3H7NO or fac-[(pypyrBr-kappa N-2,N)Re(CO)(3)Cl]center dot DMF [pypyrBr = 3-bromo-6-(1H-pyrazol-1-yl)pyridazine] is reported. The compound was synthesized by reacting Re(CO)(5)Cl with pypyrBr [3-bromo-6-(1H-pyrazol-1-yl)pyridazine] in toluene under reflux, yielding orange crystals upon purification and crystallization. Structural analysis reveals a distorted octahedral coordination environment around the Re-I center, comprising three facial carbonyl ligands, one chloride, and the bidentate pypyrBr ligand. The ligand exhibits near planarity with minimal torsional deviation, and the N-Re-N bite angle is 73.50 (12)degrees. The complex crystallizes as a 1:1 dimethylformamide solvate, consolidated by hydrogen bonding between DMF and the ligand. A Cambridge Structural Database search confirmed the novelty of this structure, as no prior reports exist for pypyrBr or its metal complexes. Spectroscopic characterization (H-1 NMR, C-13 NMR, IR) and elemental analysis support the proposed structure. This work expands the family of rhenium(I) tricarbonyl complexes with pyrazolyl-pyridazine ligands, relevant for photophysical and coordination chemistry applications.