Synthesis and characterization of thiolate, -amido, and -oxy heterocyclic-containing niobocene complexes: X-ray molecular studies of [Nb(η5-C5H4SiMe3)2(η2-N,S-S(C6H7N2))] (3)

The thermal treatment of the bis((trimethylsilyl)(cyclopentadienyl)niobium trihydride complex, [Nb(η5-C5H4SiMe3)2(H)3], with 1 equiv. of the corresponding mercapto-, hydroxy-, amino-pyridine or pyrimidine, such as 2-mercaptopyridine, 2-mercaptopyrimidine, 2-mercapto-4,6-dimethylpyrimidine; 2-hydroxypyridine, 2-hydroxy-6-methylpyrimidine, 6-hydroxy-2,4-dimethylpyrimidine, 8-hydroxyquinoline; 2-aminopyridine, 2-amino-4,6-dimethylpyridine, 2-amino-4,6-dimethylpyrimidine, affords new families of thiolate-, oxy-, amido-pyridine and -pyrimidine containing niobocene derivatives, namely [Nb(η5-C5H4SiMe3)2L] where L=(η2-N,S-S(C5H4N)) (1), (η2-N,S-S(C4H3N2)) (2), (η2-N,S-S(C6H7N2)) (3), (η2-N,O-O(C5H4N)) (4), (η2-N,O-O(C6H6N)) (5), (η2-N,O-O(C6H7N2)) (6), (η2-N,O-O(C9H6N)) (7), (η2-N,N-HN(C5H4N)) (8), (η2-N,N-HN(C7H8N)) (9), (η2-N,N-HN(C6H7N2)) (10). All the complexes were characterized by spectroscopic methods, and the molecular structure of complex [Nb(η5-C5H4SiMe3)2(η2-N,S-S(C6H7N2))] (3) has been determined by an X-ray diffraction study.