Syntheses and crystal structure of first octahedral d-metal complexes containing three and four isocyanato ligands, mer-[Mo(NCO)3py3] · 2py and trans-(py2H)[Mo(NCO)4py2]

By reaction of (NH4)2[MoCl5(H2O)] with KNCO in hot pyridine, a mixture of mononuclear complexes containing mer-[Mo(NCO)3py3] and trans-[Mo(NCO)4py2]− species (py = pyridine) has been obtained. After the separation, the crystals of two complexes, mer-[Mo(NCO)3py3] · 2py and trans-(py2H)[Mo(NCO)4py2], have been prepared. The structures of both Mo(III) complexes were confirmed by X-ray analysis.