Masahiro Mikuriya

Electrochemistry of vanadium complexes of o-N-salicylideneaminoethylphenol. A well characterized cyclic mechanism for the gain or loss of vanadyl oxygen

Abstract The electrochemistry of two vanadium complexes of o -N-salicylideneaminoethylphenol, VO(HSalamp) 2 ( 1 ) and [VO(Salamp)] 2 O ( 2 ), is reported. The oxidation of 1 , V(V)/V(IV), is completely reversible. The electrochemical properties of V(IV)/V(III) of 1 are complex and the results support a well characterized cyclic scheme mechanism. The redox reactions are accompanied by the conversions between five-coordinate oxovanadium(IV) complex and six-coordinate vanadium(III) complex by losing or gaining vanadyl oxygen. Oxidation-state-dependent change in coordination environment was also seen in the electrochemical behaviour of the complex 2 .

Synthesis and Magnetic Property of Adducts of Ruthenium(II,III) Pivalate with 9,10-Anthraquinone

Abstract Reaction of tetrakis(pivalato)diruthenium(II,III) cation dimer and 9,10-anthraquinone (aq) gave two kinds of adducts, [{Ru2(piv)4(H2O)}2(aq)]-(BF4)2 (1) (pivH = pivalic acid) and [Ru2(piv)4(aq)] n (2), depending on the condition. Very weak antiferromagnetic interaction was observed for 1. The X-ray crystal structure of 2 shows an one-dimensional chain structure.

Unexpected coordination behavior of dinucleating ligand: infinite zigzag chain of alternating sodium(I) and dinuclear-zinc(II) units

Abstract A zinc(II) complex, [Zn4Na2L2(CH3COO)4CH3CN]n· 2nCH3CN·2nH2O (H3L = 2,6-bis(saliclylideneaminomethyl)-4-methylphenol), has been isolated and characterized by X-ray crystallography, which reveals a unique zigzag-chain structure consiting of dinuclear Zn2L(CH3COO)2 units and sodium ions.

Coordination Polymers of Copper(II) and Copper(I) Trifluoroacetates with Pyrazine

Abstract New coordination polymers of copper(II) and copper(I), [Cu(tfa)2(pyz)2] n (Htfa = trifluoroacetic acid, pyz = pyrazine) (1), [Cu2(tfa)2(CH3O)2-(pyz)2] n (2), and [Cu2(tfa)2(pyz)3] n (3), have been synthesized and characterized structurally. The crystal structure of 2 consists of methoxo-bridged dinuclear copper(II) units which are connected by pyrazine molecules to form a two-dimensional network. The crystal structure of 3 shows a two-dimensional net-like structure, where each copper(I) atom has a distorted tetrahedral arrangement. The magnetic property of 2 is antiferromagnetic.

Cycloauration of 2-substituted pyridine derivatives. Synthesis, structure and reactivity of six-membered cycloaurated complexes of 2-anilino-, 2-phenoxy- and 2-(phenylsulfanyl)-pyridine

At room temperature and in ethanol 2-anilinopyridine reacted with H[AuCl4]·4H2O as well as Na[AuCl4]·2H2O to give directly the six-membered cycloaurated complex [AuCl2(pap-C n 1, N)] 1a [papxa0=xa02-(2-pyridylamino)phenyl], whereas 2-phenoxypyridine (Hpop) and 2-(phenylsulfanyl)pyridine (Hptp) produced only the salts [H2pop][AuCl4] 2b and [H2ptp][AuCl4] 2c, respectively. The adducts [AuCl3(Hpop)] 3b and [AuCl3(Hptp)] 3c have separately been prepared by the reactions of Na[AuCl4]·2H2O with Hpop and Hptp, respectively, in an acetonitrile–water mixed solvent. The salts 2b and 2c can be converted into the corresponding adducts 3b and 3c when they are stirred in acetonitrile–water at room temperature. The cycloaurated complexes [AuCl2(pop-C n 1, N)] [popxa0=xa02-(2-pyridyloxy)phenyl] 1b and [AuCl2(ptp-C n 1, N)] [ptpxa0=xa02-(2-pyridylsulfanyl)phenyl] 1c have been obtained by heating the salts or the adducts in acetonitrile–water. Moreover, complexes 1b and 1c have been synthesized directly by the reaction of H[AuCl4]·4H2O with Hpop and Hptp in refluxing acetonitrile–water, ethanol–water and propan-2-ol–water. The reaction of 1a with an equimolar amount of PPh3 in the presence of NaBF4 gave the cationic complex [AuCl(pap-C n 1, N)(PPh3)]BF4 5a, while two equivalents of PPh3 or PEt3 afforded [AuCl(pap-C1)(PPh3)2]Cl 6a or [AuCl(pap-C1)(PEt3)2]Cl 7a where the pap ligand co-ordinates through only the carbon atom. On the other hand, the C–N chelates in 1b and 1c are easily cleaved with one equimolar amount of PPh3 to give [AuCl2(pop-C1)(PPh3)] 8b and [AuCl2(ptp-C1)(PPh3)] 8c, respectively. The boat-form structures of the three six-membered auracycles have been confirmed by X-ray diffraction studies of 1b, 1c and 5a. The crystal structure of 7a has also been determined.

SYNTHESIS, STRUCTURE AND CHARACTERIZATION OF TRINITRATOTRI (N-BUTYLCAPROLACTAM) SAMARIUM (III)

Abstract The synthesis, characterization and structure of a trinitratotri(N-butylcaprolactam)samar-ium (III) complex (1) is reported. The Sm (III) ion is coordinated by nine oxygen atoms, three from NBCLM (N-butylcaprolactam) ligands, which are monodentates, and six from three bidentate nitrate groups. The geometry around the Sm (III) ion is a distorted tricapped trigonal prism. Spectroscopic and thermal decomposition data for 1 are reported. Magnetic susceptibilities of 1 were measured (80–300 K) and non-linear temperature dependence of magnetic susceptibility and effective magnetic moments were found. The effective moment is 1.8 B. M. at room temperature.