Effect of the Solvent on the Crystallographic and Magnetic Properties of Rhenium(IV) Complexes Based on 2,2' -Bipyrimidine Ligand

Two solvated rhenium(IV) complexes with formula [ReCl4(bpym)].MeCN (1) and [ReCl4(bpym)].CH3COOH & BULL;H2O (2) (bpym = 2,2 ' -bipyrimidine) have been prepared and characterized by means of Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX), single-crystal X-ray diffraction (XRD) and SQUID magnetometer. 1 and 2 crystallize in the monoclinic system with space groups P2(1)/n and P2(1)/c, respectively. In both compounds, the Re(IV) ion is six-coordinate and bound to four chloride ions and two nitrogen atoms of a 2,2 ' -bipyrimidine molecule forming a distorted octahedral geometry around the metal ion. In the crystal packing of 1 and 2, intermolecular halogen...halogen and pi. . . halogen-type interactions are present. Hydrogen bonds take place only in the crystal structure of 2. Both compounds exhibit a similar crystal framework based on halogen bonds. Variable temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show a similar magnetic behavior for both compounds, with antiferromagnetic exchange between the Re(IV) ions connected mainly through intermolecular Re-Cl. . .Cl-Re interactions.