Azido-Derivate des Pentamethylcyclopentadienyl-Vanadium(IV)-Fragments. Molekülstrukturen der Zweikernkomplexe [Cp*VCl(N3)(μ-N3)]2 und [Cp*V(N3)2(μ-N3)]2
摘要:
The stepwise reaction of Cp*VCl3 with excess trimethylsilyl azide (Me3Si-N-3) in solution leads to the paramagnetic, azido-bridged complexes [Cp*VCl2(mu-N-3)](2) (3), [CP*VCl(N-3)(mu-N-3)](2) (4) and [CP*V(N-3)(2)(mu-N-3)](2) (5) which were characterized by their IR and mass spectra. The azide-rich binuclear complex 5 is also formed if a pentane solution of Cp*V(CO)(4) is stirred in the presence of excess Me3Si-N-3 in an open vessel. According to the X-ray structure analyses both 4 and 5 are centrosymmetric molecules with a planar V(N)(2)V four-membered ring. In the absence of free trimethylsilyl azide, solutions of 3-5 lose dinitrogen slowly; in the presence of traces of air, 5 is thereby converted to the diamagnetic, ore-bridged complex [Cp*V(O)(N-3)](2)(mu-O) (6).