[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

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 (D_2d) 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 T_d. 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.