Heterotrinuclear angular aggregates of rhodium, iridium, palladium and Group 11 metals. X-Ray structure of the complex [(cod)2Rh2(µ3-C7H4NS2)2Ag(O2ClO2)](cod = cycloocta-1,5-diene)
Abstract
The binuclear complexes [{Ir(µ-C7H4NS2)(cod)}2]1(cod = cycloocta-1,5-diene) and [{Pd(µ-C7H4NS2)(η3-C3H5)}2]2 are isolated from the reaction of the chloro-bridged compounds [{M(µ-Cl)L2}2](M = Ir, L2= cod; M = Pd, L2= allyl) and lithium benzothiazole-2-thiolate. Reactions of 1 and 2 with the appropriate species [ML2(Me2CO)2]+ afford the homotrinuclear angular aggregates [M3(µ3-C7H4NS2)2(L2)3]+. Starting from [{Rh(µ-C7H4NS2)(CO)(PPh3)}2] and [{M′(µ-C7H4NS2)(cod)}2](M′= Rh or Ir), this method is highly useful to prepare the heterotrinuclear aggregates [(Ph3P)2(OC)2Rh2(µ3-C7H4NS2)2ML2]+[ML2= Ir(cod) or Pd(allyl)], [(cod)2M′2(µ3-C7H4NS2)2AgX]n+(n= 0, X = ClO4, Cl, NO3 or BF4; n= 1, X = PPh3 or pyridine) and [(cod)2M′2(µ3-C7H4NS2)2M″Cl](M″= Cu or Au). They have been characterized by 1H, 31P NMR and IR spectroscopy and [(cod)2Rh2(µ3-C7H4NS2)2Ag(O2ClO2)]8 by X-ray diffraction methods. Crystals of 8 are orthorhombic, space group Pbcn, with a= 7.635(5), b= 27.564(11), c= 15.564(8)Å, Z= 4. The structure has been solved from diffractometer data by direct and Fourier methods and refined by full-matrix least squares to R= 0.062 for 1863 observed reflections. The complex, having an imposed C2 symmetry, shows two Rh and one Ag atoms in a bent arrangement with two molecules of benzothiazole-2-thiolate interacting with all three metals. Each ligand is bonded to one Rh atom through the nitrogen and asymmetrically bridges one Rh and one Ag atom through the sulphur. The Rh atoms complete their co-ordination with a cod ligand interacting through the two olefinic bonds, while the Ag atom completes the co-ordination with two oxygen atoms from a perchlorate anion, which has been found disordered and distributed in two positions of equal occupancy factor with three oxygen atoms in common.