Reactivity of rhenium(I) pseudo-allyl complexes with heterocumulenes. Part 2. Insertion reactions

The compound [Re(CO)2(PPh3)2(mat)] [mat = anion of 2-(methylamino)thiazole] reacts under anhydrous conditions with an excess of PhNCS or CS2 to give the thioureido rhenium(I) derivative [Re(CO)2(PPh3)2SC(NPh)NMe(C3H 2NS)] (1) and the dithiocarbamate rhenium(I) complex [Re(CO)2(PPh3)2S2CNMe(C 3H2NS)] (2) respectively (C3H2NS = thiazol-2-yl). They are obtained by formal insertion of the heterocumulene into the Re-N bond. Compound (1) is triclinic, space group P1̄, with a = 15.058(6), b = 14.305(6), c = 12.371(6) Å, α = 108.51(3), β = 75.16(3), γ = 104.91(3)° and Z = 2. The structure was refined to the final conventional R of 0.055. The rhenium atom is six-co-ordinate distorted octahedral. The organic ligand chelates through the nitrogen atom of the thiazole ring and the sulphur atom of the PhNCS moiety, and together with the metal forms a non-planar six-membered ring. Selected bond distances are: Re-P 2.436 (mean), Re-C 1.89 (mean), Re-N 2.20(1), Re-S 2.471(3) Å. Compound (2) is monoclinic, space group P21/n, with a = 21.305(5), b = 17.873(5), c = 11.455(7) Å, β = 97.81(3)°, and Z = 4. The structure was refined to the conventional R of 0.052. The rhenium atom is six-co-ordinate distorted octahedral. The organic ligand chelates through the two sulphur atoms of the CS2 moiety and together with the metal forms a planar four-membered ring. Selected bond distances are: Re-P 2.431 (mean), Re-S 2.513 (mean), and Re-C 1.88 Å (mean).