The effect of hydrogen-bonding anions on the structure of metal-sulfimide complexes

Investigations into the effects of the choice of anion on the hydrogen-bonding interactions between anions and metal-sulfimide cationic complexes have led to the study of three novel compounds. Hexakis(S,S-diphenylsulfimide)cobalt(II) diiodide S,S-diphenylsulfimide acetonitrile disolvate, [Co(C12H11NS)6]I2.C12H11NS.2C2H3N, crystallizes in the centrosymmetric space group P-1 with Z = 2. Six diphenylsulfimide ligands coordinate to the cobalt centre through their N atoms. Two iodide counter-ions hydrogen bond to the cation through N-H...I interactions, with N...I distances in the range 3.7302 (19)-3.8461 (19) A. One extra molecule of sulfimide is included in the asymmetric unit, regardless of the metal-ligand ratio used in the synthesis, and this sulfimide molecule also hydrogen bonds to one of the iodide counter-ions through one N-H...I hydrogen bond. The reaction of FeCl3.6H2O with S,S-diphenylsulfimide monohydrate yields hexakis(S,S-diphenylsulfimide)iron(III) trichloride, [Fe(C12H11NS)6]Cl3. The complex crystallizes in the centrosymmetric cubic space group Pa-3 and the asymmetric unit contains one-sixth of a formula unit. Two of the chloride anions each hydrogen bond to three sulfimide NH groups on opposite sides of the [Fe(Ph2SNH)6]3+ cation. The third chloride anion does not take part in any strong hydrogen bonding; instead it is surrounded by aromatic groups and is involved in C-H...Cl hydrogen bonds. The reaction of [Pt(Ph2SNH)4]Cl2 with I2 facilitates oxidation of the Pt(II) metal centre to Pt(IV), producing tetrakis(S,S-diphenylsulfimide)diiodoplatinum(IV) dichloride dichloromethane disolvate, [PtI2(C12H11NS)4]Cl2.2CH2Cl2. The crystal structure is centrosymmetric, with the elongated octahedral cationic complex situated on an inversion centre. The chloride anions are hydrogen bonded to the cation through N-H...Cl hydrogen bonds, with two cis NH groups hydrogen bonded to each anion. Strong hydrogen bonding within these three compounds is limited to N-H...halide hydrogen bonds between the cation and two anions, with a three-up/three-down arrangement of the NH groups in the first two compounds. The anions also 'cap' the NH groups in the third compound. In all three cases, the anions are also involved in weaker hydrogen bonds utilizing the plethora of relatively acidic aryl CH groups in the structures.