Synthesis and characterization of new technetium(I) and rhenium(I) Schiff base complexes. Crystal structure of [M(PPh3)2(CO)2 {(C3H2NS)NCHC6H4O}] (MTc, Re; C3H2NSThiazol-2-yl)

[M(PPh3)2(CO)3Cl] (M Tc, Re) reacts with the lithium salt of the Schiff base N-orthohydroxybenzylidene-2-thiazolylimine in boiling THF to yield [M(PPh3)2(CO)2 {(C3H2NS)NCHC6H4O} ]. The structure of the two isomorphous complexes has been determined by X-ray crystallography based on single- crystal diffractometer data and refined to the final R factor of 0.039 for the Re complex and 0.059 for the Tc complex. The compounds are monoclinic, space group P21/n, with Z=4. Crystal data are: [Re- (PPh3)2(CO)2(L)] (L=Schiff base ligand),a=17.875(5), b=24.948(4), c=9.279(5) Å, β=102.39(3)°; [Tc(PPh3)2(CO)2(L)], a=17.905(5), b=24.895(4), c=9.285(6) ) Å, β=102.63(3)°. The metal ions are six-coordinate distorted octahedral, with trans PPh3, cis CO groups, and one chelate bidentate anion. Structural details compare very favourably in the two complexes. Selected bond lengths are: ReP (mean) 2.44, ReC (mean) 1.89, ReO 2.157(5), ReN 2.211(6); TcP (mean) 2.44, TcC (mean) 1.89, TcO 2.164(5), TcN 2.210(7) Å. © 1989.