Synthesis and molecular structures of niobocene derivatives containing Nb-Sn-Nb metallochain

The [Cp2Nb(CO)]2SnCl2 (1) complex is synthesized in the form of crystals with 63% yield by the Cp2Nb(CO)H reaction wih SnCl4 in THF in the presence of Et3N. The complex 1 is also prepared by interaction of Cp2Nb(CO)H with Cp2Nb(CO)SnCl3 with 16% yield. The crystalline more sluble analog [(CH3C5H4)2Nb(CO)]2 ShCl2(2) is extracted, which contains the chain of Nb-Sn-Nb with short Nb-Sn(2.840)2)A bonds and 140.69(5) deg angle between them. The (Cp2NbH)2Sn(Cl)Et (3) complex is prepared wih 12% yield, possessing the structure analogous to type 2. In 3 each fragment CpNb is connected with the terminal hydride (Nb-H, 1.66(1) and 1.69(1)A) atom forms shortened bond with tin atom Nb-Sn 2.868(1) and 2.856(1) A, NbSnNb angle is 129.44(5)