STUDIES ON ORGANOMETALLIC COMPOUNDS WITH HETERO MULTIPLE BRIDGES .5. CRYSTAL AND MOLECULAR-STRUCTURE OF PARENT RHENIUM COMPLEX RE2BR2(CO)6(THF)2 AND SUBSTITUTED PRODUCTS OF TRICARBONYLRHENIUM(I) DERIVED FROM IT

Reactions of the tetrahydrofuran adduct Re2Br2(CO)6(THF)2 with some phosphorous- and nitrogen-containing donors under mild conditions are reported, which led to the formation of substituted products of tricarbonylrhenium(I). Bromide abstraction from the THF adduct by secondary amines and CS2 produced the dithiocarbamato derivatives Re(S2CNR2)(CO)3(HNR2) whose behaviour in solution with CO was also investigated. Mass spectral data for some of the substituted products have been measured. The title compound crystallizes in the space group P21/n with cell constants a = 8.661(2), b = 11.251(3), c = 11.424(3) Å and β = 110.36(2)°, U = 1043.67 Å3 and Dcalc = 2.686 g cm-3, Z = 2. The molecule consists of a planar Re2Br2 moiety, as demanded by symmetry. The two THF groups are on opposite sides of this plane and the three CO groups around each rhenium atom are arranged in a fac arrangement. The unique ReBr distances are 2.642(5) and 2.644(4)Å, while the ReO distance is 2.129(31) Å. The ReBrRe and BrReBr angles are 97.3(2) and 82.7(1)°, respectively. The Re⋯Re nonbonding distance is 3.967(3) Å. The THF ligands consist of a nearly planar C4 fragment (maximum deviation from planarity 0.06 Å), while the oxygen is 0.348 Å out of that plane, the angle defined by the C4 plane and the COC fragment of the THF ligand being 24.99°. Final values of the discrepancy indices are R(F) = 0.074 and Rw(F) = 0.095. © 1978.