S(2-PYRIDYLMETHYL)AMINE-N,N',N'',N''']RHENIUM(IV)) TETRAKIS(HEXAFLUOROPHOSPHATE) DIACETONE TETRAHYDRATE

The title compound, u-O)(2)(C18H18N4)(2)](PF6)(4).-2(CH3)(2)CO.4H(2)O, was structurally characterized. The structure of the complex cation c onsists of a binuclear unit, (tpa)Re(mu O)(2)Re(tpa) [tpa = tris(2-pyr idylmethyl)amine], having a crystallographically imposed centre of sym metry at the midpoint of Re=Re triple bond. Each Re ion is in a pseudo -octahedral coordination environment comprising two bridging O atoms a nd four N atoms of tpa, in which the tertiary amine and one of the pyr idine N atoms ar trans to the oxo bridge. The Re=Re distance, average Re-O distance and Re-N distances are 2.364 (1), 1.950 (6) and 2.105 (7 )-2.150 (6) Angstrom, respectively.