Synthesis and characterization of nicotinic acid coordinated metal carbonyl complexes

Two zero-valent metal carbonyl complexes fac- [M(CO)3(NIC)3] (where M = Mo, W; 3, 4; NIC = 3-HO2CC5H4N) have been synthesized and characterized by elemental and thermal analyses (TGA, EGA), IR and powder x-ray diffraction (XRD) spectroscopic techniques. The IR spectrum of complex 3 exhibits three CO stretching bands and 4 shows two CO stretching bands in addition to a carboxylic-carbonyl stretching band. The possibility of fac / mer isomerization in complex 3 has been studied by IR spectroscopy in various solvents. Elemental and mass spectrometric data are consistent with the formulae of the title complexes. The powder x-ray diffractogram of complexes 3 and 4 exhibit similar pattern suggesting the same geometry.