Dmitry A. Mainichev

New {RuNO} Polyoxometalate [PW11O39RuII(NO)]4-: Synthesis and Reactivity

New Ru-containing polyoxometalate [PW11O39Ru(II)(NO)](4-) (1(4-)) was obtained in high yield by reaction of [Ru(NO)Cl5](2-) with [PW11O39](7-) and characterized by multinuclear NMR, cyclic voltammetry, IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). The intrinsic reactivity of the {RuNO} site in 1(4-) toward various reagents has been studied using a versatile and simple ESI tandem mass spectrometric methodology for identification of the L attached at the Ru site; this approach relies on the preferential liberation of the L ligands attached at the Ru sites upon mass-selecting desired intermediates and subsequent promotion of their fragmentation. Reactions with both hydrazine and hydroxylamine lead to elimination of the nitroso group and quantitative formation of [PW11O39Ru(III)(H2O)](4-) (2(4-)) in aqueous solution. In the reaction with hydroxylamine, an intermediate with coordinated dinitrogen has been detected. An easy access to the NH3-coordinated [PW11O39RuNH3](4-) (3(4-)) complex was achieved upon reduction of 1(4-) with Sn(2+) in water.

Cd2+ complexation with P(CH2OH)3, OP(CH2OH)3, and (HOCH2)2PO2(-): coordination in solution and coordination polymers.

The coordination of Cd(2+) with P(CH(2)OH)(3) (THP) in methanol was followed by (31)P and (111)Cd NMR techniques. A cadmium-to-phosphine coordination ratio of 1:3 has been established, and effective kinetic parameters have been calculated. Air oxidation of THP in the presence of CdCl(2) at room temperature produces coordination polymer (3)(∞)[Cd(3)Cl(6)(OP(CH(2)OH)(3))(2)] (1). The same oxidation reaction at 70 °C gives another coordination polymer, (∞)[CdCl(2)(OP(CH(2)OH)(3))] (2). Complexes 1 and 2 are the first structurally characterized complexes featuring OP(CH(2)OH)(3) as a ligand that acts as a linker between Cd atoms. The addition of NaBPh(4) to the reaction mixture gives coordination polymer (∞)[Na(2)CdCl(2)(O(2)P(CH(2)OH)(2))(2)(H(2)O)(3)] (3) with (HOCH(2))(2)PO(2)(-) as the ligand. Coordination polymers 1-3 have been characterized by X-ray analysis, elemental analysis, and IR spectroscopy.

Xanthate complexes of {Nb2S4}4+

Alkyl xanthate complexes [Nb2S4(S2COR)4] (R = Et (I), iso-Pr (II), n-Bu (III), and iso-Am (IV)) are synthesized by the ligand exchange reaction in solutions from (Et4N)4[Nb2S4(NCS)8] and the corresponding potassium salts in satisfactory yields. The X-ray diffraction analyses are carried out for the isopropyl xanthate (II) and butyl xanthate (III) complexes. From the view point of mutual arrangement of chelate cycles, complexes II and III exist in crystals as ΛΔ isomers. The niobium-niobium distances are 2.8789(4) Å in complex II and 2.8856(3) Å in complex III. The first example for the formation of short S...S contacts between the disulfide ligands of the {Nb2S4}4+ fragments in the crystal structure of III is found (3.146 Å).

A novel water-soluble sulfide cluster of iron: synthesis, properties, and intercalation into molybdenum disulfide

A novel water-soluble sulfide cluster of iron, {Fe6S8[P(CH2OH)3]6}2+, was obtained from ferrous chloride tetrahydrate, tris(hydroxymethyl)phosphine, and H2S in methanol. A reaction of the cluster in solution with dispersed molybdenum disulfide gave an inclusion compound, MoS2({Fe6S8[P(CH2OH)3]6}Cl2)0.06. The products obtained were characterized by IR, NMR, and ESR spectroscopy, electronic absorption spectroscopy, mass spectrometry, and elemental analysis. The magnetic susceptibility of the cluster was studied in solution and in a molybdenum disulfide matrix.