MO-2(OCH(2)(T)BU)(6)(CP)NA(DME) - PREPARATION, STRUCTURE, AND SOLUTION BEHAVIOR

From the reaction between Mo-2(OCH(2)(t)Bu)(6) and NaCp (Cp=C5H5) in T HF the title complex was obtained as a crystalline product in the pres ence of DME (DME=dimethoxyethane). Crystal data for Mo-2(OCH(2)(t)Bu)( 6)(Cp)Na(DME) at -167 degrees C: a=11.885(2) Angstrom, b=19.240(1) Ang strom, c=11.562(2) Angstrom, alpha=102.73(1)degrees, beta=106.95(1)deg rees, gamma=98.55(1)degrees, Z=2 and space group of <P(1)over bar>. In the solid state there is an unbridged M=Mo bond of distance 2.276(1) Angstrom. One Mo atom is bonded to four alkoxides, two of which are al so bonded to Na+ while the other is eta(5)-bonded to the Cp ligand, wi th Mo-C distances ranging from 2.34 to 2.66 Angstrom, and to two OR gr oups, one of which is bound to the Nai ion. In addition to the coordin ation to three OR groups the Na+ ion binds one DME molecule via both o f its ether oxygen atoms. The Mo-O distances fall in the range 1.91-2. 01 Angstrom with the longer distances being associated with those grou ps that are also bonded to the Na+ ion, in polar solvents the title co mplex dissociates to give Mo-2(OCH(2)(t)Bu)(6) and Na+ Cp(-).