Ruthenium carbonyl 1,4-diaza-1,3-butadiene (R-DAB) complexes. Reactivity of Ru 2(CO) 6(R-DAB) towards hetero-allenes L(L = carbodiimide, sulphine), resulting in CC bond formation. X-ray molecular structure of Ru 2(CO) 5 (t=BuNCHC(H)(N-t-Bu)C(N- p-Tol)N- p-Tol) and of Ru 2(CO) 5(i-PrNCHC(H)(N-i-Pr)C(S)C 12H 8)

Abstract

Ru 2(CO) 6(R-DAB)(R-DAB = 1,4-disubstituted-1, 4-diaza-1,3-butadiene = RNCHCHNR) (R-DAB) stands for RNCHCHNR: DAB = 1,4- diaza-1,3-butadiene, see. ref. 1) reacts with hetero-allenes L (L=carbodiimide = RŃCNR′, R′ = p-Tol, i-Pr, c-Hex, R = t-Bu; L = thiofluorenone-S-oxide=C 12H 8CSO, R = i-Pr, t-Bu, c-Hex) to yield C(R-DAB)C(L) coupled products. From the reaction of Ru 2(CO) 6(t-Bu-DAB) with R′NCNR′, Ru 2(CO) 5(t-BuN CHC(H)(Nt-Bu)C(NR′)(Ru 2(CO) 5(AIP{t-Bu,R′}), AIP = 1,2-di- amino-2,3-di- imino- propane) is obtained. The AIP-moiety is bonded to the two Ru atoms via three of the four N-atoms, while the R′N-imine atom is not coordinated. This was proven by an X-ray crystal structure determination for R′ = p-Tol. Crystals of Ru 2(CO) 5(AIP{t-Bu, p-Tol}) are triclinic, space group P 1 and cell constants: a = 16.69(2), b = 19.65(2) and c = 12.46(2) Å, α = 102.83(6), β = 108.24 and γ = 64.53(10)°; Z = 4.6546. Reflections were used in the refinement, resulting in a final R = 0.056. There are two independent molecules in the unit cell, having only slightly different geometries. The single Ru(1)Ru(2) bond of 2.779(1) Å (mean) (throughout this paper, standard deviations of mean values are calculated by σ = {χi(χi – χ) 2/N(N –1} 1 2 ) is spanned by a slightly asymmetrically bridging carbonyl group (C(3)O(3)). Each Ru-atom is coordinated by two terminal CO-groups. The organic t-Bu-N(1)C(6)C(7)(t-BuN(2))C(8) ( p-Tol-N(4)) p-Tol-N(3) fragment is σ-N bonded via N(1) to Ru(2) while the amino N(2)- and N(4)-atoms are both symmetrically bridging the Ru(1)(2) bond. N(3) is in non-bonding position with respect to both Ru-atoms. The intra-ligand bond distances are in accord with a reduction of one imine bond of the former t-Bu-DAB ligand: C(7)N(2) = 1.50(1) Å (mean). The new C(7)C(8) bond has a bond length of 1.53(1) Å (mean). During the reaction of Ru 2(CO) 6(R-DAB) with the sulphine C 12H 8CSO, CO 2 gas evolved and the product, i.e. Ru 2(CO) 5(RNCHC(H)(NR)C(S)C 12H 8) no longer contains the sulphine's oxygen, as was proven by an X-ray crystal structure determination for R = i-Pr. Crystals of Ru 2(CO) 5(i-PrNCHC(H)(N-i-Pr)C(S) C 12H 8) are orthorhombic: space groups P2, 12 12 1 and cell constants a = 14.822(5), b = 16.951(28) and c = 25.413(16) Å; Z = 8.1304. Reflections were used in the refinement, resulting in a final R = 0.047. There are two independent molecules in the unit cell having non-significant differences in geometry. The single Ru(1)Ru(2) bond of 2.811(1) Å (mean) is bridged by one carbonyl group (C(22)O(1)). Furthermore, each Ru-atom is coordinated by two terminal CO groups. The organic i-Pr(N(2)C(2) C(1)(i-PrN(1)C(3)(S)C 12H 8 moiety is σ-N(2) bonded to Ru(2). The N(1) symmetrically bridges the Ru(1)Ru(2) bond, while S does so asymmetrically: Ru(1)S = 2.43(1), Ru(2)S = 2.54(1) Å (mean). All complexes were characterized by IR-,FD-mass-and 1H NMR-spectroscopy.