Synthesis, crystal structure, and vibrational spectra of cis-(CH2Py2)[ReBr4Py2](2) center dot (CH3)(2)CO

By reaction of (n-Bu4N)(2)[ReBr6] with pyridine and (n-Bu4N)BH4 in dichloro methane halogeno-pyridine-rhenium(III)complexes are formed and purified by chromatography. X-ray structure determination on a single crystal has been performed of cis-(CH2Py2)[ReBr4Py2](2).(CH3)(2)CO (monoclinic, space group P2(1)/c, a = 15.0690(9), b = 8.3337(8), c = 35.588(4) Angstrom, beta = 96.4 09(7), Z = 4). Based on the molecular parameters of the X-ray structure det ermination and assuming C-2 point symmetry for the anion cis-[ReBr4Py2](-) the IR and Raman spectra are assigned by normal coordinate analysis. The va lence force constants are in the Br-Re-Br axis f(d)(ReBr) =1.49, in the asy mmetrically coordinated N'-Re-Br' axes f(d)(ReBr') = 1.03 und f(d)(ReN') = 2.52 mdyn/Angstrom.