MIXED-LIGAND COMPLEXES OF RHENIUM .3. SYNTHESIS, CHARACTERIZATION ANDSTRUCTURES OF [REN(ME2PHP)2(MNT)] AND [REN(ME2PHP)(2,6-DMTP)(MORPHTCB)] (ME2PHP = DIMETHYLPHENYLPHOSPHINE - 2,6-DMTP- = 2,6-DIMETHYL-THIOPHENOLATE - MORPHTCB- = N-(MORPHOLINYLTHIOCARBONYL)-BENZAMIDINATE)

Novel rhenium(V) nitrido complexes have been prepared by ligand exchan ge procedures starting from [ReN(Cl)(Me2PbP)2(morphtcb)] and 2,6-dimet hylthiophenol, 2,6-DMTPH, or sodium 1,2-dicyanoethene-1,2-dithiolate, Na2mnt. [ReN(Me2PhP)(2,6-DMTP)(morphtcb)] and [ReN(Me2Php)2(mnt)] are neutral, air-stable complexes which have been spectroscopically charac terised and studied by X-ray diffraction. [ReN(Me2Php)2(mnt)] crystall ises triclinic in the space group P1BAR (a = 9.802(3), b = 10.215(2), c = 12.389(3) angstrom, alpha = 69.38(2), e = 85.84(2), gamma = 78.84( 6)-degrees) with Z = 2. The final R value is 0.021. The rhenium atom i s five-coordinate with the nitrido nitrogen at the apex of a distorted square pyramid. [ReN(Me2PhP)(2,6-DMTP)(morphtcb)] crystallises monocl inic in the space group P2(1)/c (a = 11.609(2), b = 11.677(1), c = 21. 923(6) angstrom, beta = 92.59(1)-degrees) with Z = 4. Structure soluti on and refinement based on 4626 reflections converged at R = 0.032. Th e coordination polyhedron is a square pyramid which is significantly d istorted towards a trigonal bipyramid.