6b grubu elementlerinin bazı pentakarbonil(piridin)metal(0) komplekslerinin sentezi ve spektroskopik olarak incelenmesi

The photolysis of hexacarbonylmetal(0); M: Cr, Mo, W, complexes inthe presence of a substituted pyridine ligand (4-methylpyridine, 4-tbutylpyridineand 4-dimethylaminopyridine) at 10oC yields the correspondingpentacarbonyl-N-pyridinemetal(0) complexes. These complexes are purifiedunder high vacuum and their structures are investigated by using IR- ,1H- and13C-NMR spectroscopies.The IR spectroscopy results showed three absorption bands (one instrong, the others in medium intensities). The appearance of three absorptionbands in the carbonyl region of these complexes indicates that the M(CO)5 -unit of the complexes has a local C4v symmetry.The 1:4 ratio of CO peaks in the 13C-NMR spectroscopies proved thatthe symmetry of these complexes is C4v . Besides, the 1H- and 13C-NMRspectroscopies showed that the pyridine ligand bonded to metal complexthrough the pyridine nitrogen atom symmetrically.Keywords: pyridine, chromium, photochemical synthesis, metal-ligand bond