CRYSTAL-STRUCTURE AND BONDING OF [W(O-T-BU)(4)(THF)]

[W(O-t-Bu)(4)(THF)] is formed from [WCl4(SEt2)(2)] and LiO-t-Bu in boi ling tetrahydrofuran and characterized by a crystal structure analysis . The compound crystallizes in the tetragonal space group I4 with Z = 2 and the lattice dimensions a = b = 1158.8(2) and c = 940.7(2) pm at 80 degrees C. [W(O-t-Bu)(4)(THF)] shows the molecular structure of a t etragonal pyramid with the oxygen atom of the THF molecule in the apic al position. Surprisingly, the tungsten atom is deflected by 34 pm fro m the plane of the four oxygen atoms of the O-t-butyl groups against t he direction of the W-O(THF) bond. The bonding modes are discussed on the basis of MO considerations.