| dc.description.abstract |
Reactions of (NBu4)[ReOCl4] and 3,3,3?, 3?-tetraalkyl-1,1?-isophthaloylbis(thioureas), H 2
phth(R2tu)2 where R = Et, i-Bu, in hot MeOH with the addition of Et3N give red products of the
composition [ReO(OMe){phth(R2tu)2}]2 (8a, R = Et; 8b, R = i-Bu). X-ray structures of 8 reveal symmetric
binuclear complexes containing two almost coplanar organic ligands, each of which coordinates to two
rhenium centers via the two bidentate-O,S moieties. The octahedral coordination spheres of the rhenium
atoms are completed by each one oxo and one methoxido ligand which are directed perpendicular to the
plane defined by the {phth(R 2tu)2}2- ligands. While in 8a, both methoxido ligands point to the same side
of the described plane and form a syn isomer, the MeO- ligands in 8b are located at opposite sides and form
an anti isomer. Studies in solution show that there exists a reversible equilibrium between the anti and syn
isomers. Dimerization/condensation of complexes 8 with the formation of tetranuclear complexes of the
composition [{ReO{phth(R 2tu)2}}2O]2 (9) and/or polynuclear species is observed in solutions, which do
not contain MeOH. ?? 2010 American Chemical Society. |
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