Mn(SPh)3Cl]2-, [Mn(SPh)3Br]2-, [Mn(SePh)4]2-, [Mn(TePh)4]2-, and [Co4(SPh)6Cl4]2-: New Mixed Halide/Thiolate and Chalcogenolate Complexes of Manganese and Cobalt

Abstract

The reactions of 1:1:1 molar ratio mixtures of NaSPh/MnCl2/Et4NBr and NaSPh/CoCl2/ Et4NCl in methanol afford the compounds [Et4N]4[Mn(SPh)3Br][Mn(SPh)3Cl] (1) and [Et4N]2[Co4(SPh)6Cl4] · MeCN (2), respectively, with the following crystal data: a = 14.408(5), b = 13.788(4), c = 17.984(5) Å, β = 90.16(2)°, space group P21/c and Ζ = 4 for 1, and a = 21.976(4), b = 13.081(2), c = 22.012(4) Å, β = 105.48(1)°, space group P 21/c for 2. The structures were refined to R values of 0.049 and 0.037, respectively. Crystals of 1 contain both of the paramagnetic (S = 5/2) mononuclear anions [Mn(SPh)3Br]2- (3 a) and [Mn(SPh)3Cl]2- (3b). The anions 3 a and 3 b are superimposed in an averaged unit cell and thus occupy crystallographically equivalent sites, the positions of the chlorine and bromine atoms being unresolved. The monohalide species are distributed statistically over 93% of the total anion positions. The remaining 7% are occupied by the dihalide species [Mn(SPh)2Br2]2- (4a) and [Mn(SPh)2BrCl]2- (4b) in equal amounts. In all these cases the metal atoms exhibit a distorted tetrahedral stereochemistry. In crystals of 2 [Co4(SPh)6Cl4]2- anions (5) are observed which feature a {Co4S6Cl4} core consisting of a distorted (D2d) Co4 tetrahedron inscribed in a moderately irregular S6 octahedron defined by bridging S atoms of an adamantane type cage. The four chlorine atoms each bind to different Co atoms and define an outer Cl4 tetrahedron, such that the overall symmetry of the {Co4S6Cl4} core comes close to Td. The results presented show that [M3(SPh)3Hal6]3- type species reported for M = Fe are not as readily formed for M = Mn and Co in methanolic solution, where other species are found instead. Physical properties such as solid state susceptibilities and 1H NMR spectra confirm the identity of 1 and 2. Reactions of 4:1:2 molar ratio mixtures of NaSePh/MnCl2/Et4NCl and NaTePh/MnCl2/Et4NCl in methanol lead to [Et4N]2[Mn(SePh)4] (6) and [Et4N]2[Mn(TePh)4] (7). Both compounds crystallize in the monoclinic space group P21/n with a = 16.162(4), b = 15.323(4), c = 16.949(4) Å, β = 91.28(2)°, Z = 4 for 6, and a = 16.367(6), b = 15.641(7), c = 17.220(7) Å, β = 92.00(3)°, Z = 4 for 7. Their structures were refined to R = 0.077 and 0.026, respectively. Four benzeneselenolate and benzenetellurolate ligands provide a slightly distorted tetrahedral coordination about the Mn(II) center for 6 and 7, respectively. The Mn–Se and Mn–Te distances average 2.567 and 2.742 Å, the Se– Mn– Se and Te–Mn–Te angles range from 99.1(1) to 124.2(1) and from 94.7(1) to 127.0(1)°, respectively.