Synthesis, characterization, and structures of new titanocene isoselenocyanato complexes

The complexes [Ti(eta(5)-C(5)H(4)R)(2)(NCse)(2)] [R = Me (1), SiMe(3) (2), or SiEt(3) (3)] were prepared from the corresponding dichlorides with KSeCN in acetone; the oxygen-bridged complex [Ti(eta(5)-C(5)H(4)Me)(2)(NCSe)]O-2 (4) was formed by air oxidation of (1). All complexes were characterized by elemental microanalysis and by IR, H-1 NMR, and mass spectroscopies. An X-ray analysis of (1) and (4) confirms the results of IR studies that these complexes contain N-bonded selenocyanate ligands. In molecules (1) and (4) there is a pseudotetrahedral arrangement about each titanium. The N-C-Se chains are linear with normal N-C and C-Se bond distances. The dimer (4) contains an approximately linear Ti-O-Ti bridge (angle 173.4 degrees) with a Ti-O bond distance of 1.838 Angstrom. The structural results are compared with those in related compounds.