14552-78-4Relevant academic research and scientific papers
Crystal structures of dichlorobis(triphenylphosphine oxide)zinc(II) and dibromobis(triphenylphosphine oxide)zinc(II) and an EPR study of manganese(II) in dibromobis(triphenylphosphine oxide)zinc(II)
Kosky, Charles A.,Gayda, Jean-Pierre,Gibson, John F.,Jones, Stephen F.,Williams, David J.
, p. 3173 - 3179 (1982)
The structures of ZnX2(OPPh3)2 (X = Cl, Br) have been determined. Crystals of the chloride are orthorhombic, with a = 32.95 (1) ?, b = 20.702 (6) ?, c = 9.792 (3) ?, space group Fdd2, and Z = 8; those of the bromide are triclinic, with a = 10.188 (1) ?, b = 9.987 (1) ?, c = 11.189 (1) ?, α = 114.58 (1)°, β = 121.29 (1)°, γ = 89.82 (1)°, space group P1, and Z = 1. The environment of the metal atom in each case approximates to a tetrahedral arrangement of two oxygens and two halide ions. A single crystal of the bromide doped with manganese in the zinc site was studied by electron paramagnetic resonance at room temperature, and its spin Hamiltonian parameters are reported, notably D = 0.523 cm-1 and E = 0.133 cm-1. The high value of D for the bromide relative to that of the chloride is in keeping with the general observation that D increases in the order of Cl a given class of compound, which is also the order of increasing electron release from the ligand. The orientations of the principal values of D found for the bromide are used as a basis for assigning their most probable orientations in the chloride, where there are two magnetically independent molecules. We observe that the principal axes of D avoid the bond directions, Dx lying along or close to the bisector of the XMnX direction (X = Cl, Br) and Dy and Dz lying close to the OMnX planes (X = Cl, Br). Chlorine, being the more electronegative, more strongly influences the direction of Dy in the chloride than does bromine in the bromide. But in the latter the π-electron density of a phenyl group may be a contributory factor.
A thermochemical study involving adducts MX2*P(C6H5)3O (M = Zn, Cd, Hg; X = Br, I)
Queiroz, Jose C.,Airoldi, Claudio,Chagas, Aecio P.
, p. 709 - 714 (2007/10/02)
The standard molar enthalpy ΔrH0m of the reaction: MX2(s) + 2P(C6H5)3O(s) = MX2*2P(C6H5)3O(s), where M = Zn, Cd, Hg and X = Br, I (except HgI2) was obtained through the determination of the enthalpy of dissolution of the metal halides, ligand, and adducts in calorimetric solvent, giving the values: -(69.92 +/- 1.10); -(63.02 +/- 0.39); -(16.02 +/- 0.56); -(30.55 +/- 0.87); and -(16.48 +/- 1.14) kJ/mol, for the sequence of halides: ZnBr2, ZnI2, CdBr2, CdI2, and HgBr2.The standard molar enthalpies of formation were also determined: -(622.2 +/- 6.8), -(495.0 +/- 6.3), -(556.2 +/- 6.5), -(457.8 +/- 7.1), and -(411.1 +/- 6.4) kJ/mol, for the above sequence as well as the standard enthalpies of reaction: ΔdH0m for MX2*2P(C6H5)3O(s) = MX2(s) + 2P(C6H5)3O(g); and ΔlattH0m for MX2*2P(C6H5)3O(s) = MX2(g) + 2P(C6H5)3O(g).The mean enthalpy of dissociation of the metal-oxygen bond, (M-O), was also estimated and compared with other results.
