Electrochemical studies of ruthenium compounds part I. ligand oxidation levels

This article does not have an abstract

Synthesis, characterization and properties of nickel(II)pseudohalide complexes of types [Ni(pap)₂(X)₂], [Ni(pap)₂(X)]₂(Y)₂ and [Ni(pap)(N₃)₂]_n [pap=2-(phenylazo)pyridine; X=N₃^ˉ, NCSˉ, NCOˉ; Y=ClO₄ˉ, PF₆ˉ]

2474-2479Three different types of nickel(II)pseudohalide compounds, viz. red-brown [Ni(pap)2(X)2] [pap=2-(phenylazo)pyridine; X=N3ˉ, 1; NCSˉ, 2; NCOˉ 3], greenish-brown [Ni(pap)2(X)]2(Y)2  (X= N3ˉ , Y=ClO4ˉ, 4; X= N3ˉ  , Y=PF6ˉ , 5; X=NCOˉ, Y=ClO4ˉ, 6; X= NCOˉ, Y= PF6ˉ, 7) and brownish-green, [Ni(pap)(N3)2]n (8) have been prepared and characterised on the basis of microanalytical, spectroscopic, magnetic, electrochemical and other physicochemical properties. In IR, v(N=N) stretching frequency is observed at considerably lower frequencies (-1370 cm-1) than the free ligand value (1425 cm-1) indicating substantial Ni (II)→ pap π-back bonding and in electronic spectra, the MLCT bands show characteristic lower energy shifts in going from mono- to polynuclear compounds via dinuclear ones. Room temperature magnetic measurements show uniformly two-electron paramagnetism for each nickel(II) ion in these complexes. Electrochemical electron transfer study reveals nearly- reversible responses corresponding to NiIII/NiII couple in acetonitrile solutions. On the negative side of SCE, multiple ligand reductions pertaining to azo reductions are observable

Synthesis, characterization and properties of nickel(II)pseudohalide complexes of types [Ni(pap)₂(X)₂], [Ni(pap)₂(X)]₂(Y)₂ and [Ni(pap)(N₃)₂]_n [pap=2-(phenylazo)pyridine; X=N₃^ˉ, NCSˉ, NCOˉ; Y=ClO₄ˉ, PF₆ˉ]

2474-2479Three different types of nickel(II)pseudohalide compounds, viz. red-brown [Ni(pap)2(X)2] [pap=2-(phenylazo)pyridine; X=N3ˉ, 1; NCSˉ, 2; NCOˉ 3], greenish-brown [Ni(pap)2(X)]2(Y)2  (X= N3ˉ , Y=ClO4ˉ, 4; X= N3ˉ  , Y=PF6ˉ , 5; X=NCOˉ, Y=ClO4ˉ, 6; X= NCOˉ, Y= PF6ˉ, 7) and brownish-green, [Ni(pap)(N3)2]n (8) have been prepared and characterised on the basis of microanalytical, spectroscopic, magnetic, electrochemical and other physicochemical properties. In IR, v(N=N) stretching frequency is observed at considerably lower frequencies (-1370 cm-1) than the free ligand value (1425 cm-1) indicating substantial Ni (II)→ pap π-back bonding and in electronic spectra, the MLCT bands show characteristic lower energy shifts in going from mono- to polynuclear compounds via dinuclear ones. Room temperature magnetic measurements show uniformly two-electron paramagnetism for each nickel(II) ion in these complexes. Electrochemical electron transfer study reveals nearly- reversible responses corresponding to NiIII/NiII couple in acetonitrile solutions. On the negative side of SCE, multiple ligand reductions pertaining to azo reductions are observable

Isomeric 2-(arylazo)pyridine complexes of osmium dichloride and osmium dibromide

This article does not have an abstract

Synthesis, characterization and properties of mono-, di- and polynuclear nickel(II) pseudohalide complexes containing bidentate Schiff bases. X-ray structure of [Ni(Ni,Np)₂(NCS)₂] [Ni,Np = N-((pyridin-2-yl)benzylidene) benzylamine]

9-17Three different types of nickel(II) pseudohalide compounds, [Ni(Ni,Np)₂(X)₂] [Ni,Np = N-((pyridin-2-yl)benzylidene) benzylamine; X = N₃⁻, 1; X = NCS⁻, 2; X = NCO-, 3], [Ni(Ni,Np)₂(X)]₂(Y)₂ [X = N₃⁻, Y = ClO4⁻, 4; X = N₃⁻, Y = PF6⁻, 5; X = NCO⁻, X = ClO4⁻, 6; X = NCO⁻, Y = PF6⁻, 7] and [Ni(Ni,Np)(N₃)2]n (8) have been prepared and characterized using microanalytical, spectroscopic and other physicochemical results. Single crystal X-ray study of one of the mononuclear compounds, [Ni(Ni,Np)₂(NCS)₂] (2) has been done. Structural analysis reveals that the metal center in 2 adopts a distorted octahedral geometry with an NiN6 chromophore coordinated through four N atoms of two bidentate L units and two N atoms of terminal thiocyanate in mutual cis orientation. The mononuclear units in 2 are engaged in intermolecular weak C-H…S hydrogen bonding to give a 1D chain. Electrochemical electron transfer study reveals nearly-reversible responses to NiIII/NiII couple in acetontrile solutions. High-energy intraligand 1(π-π *) fluorescence at room temperature and intraligand ³ (π-π*) phosphorescence in glassy solutions (MeOH at 77 K) are seen in all the complexes

Synthesis and characterization of [Mn(diik)₃](ClO₄)₂ [diik = N,N'-carbonyldiimidazole and [Mn(imH)₆](ClO₄)₂ [imH = imidazole]: A 2D supramolecular sheet structure in [Mn(imH)₆](ClO₄)₂ through N-H…O and C-H…O hydrogen bonds

1753-1757Two mononuclear complexes [Mn(diik)₃](ClO₄)₂ (1) [diik = N,N'-carbonyldiimidazole] and [Mn(imH)₆](ClO₄)₂ (2) [imH = imidazole] are isolated and characterized using microanalytical, spectroscopic and other physicochemical results. X-ray structural study of 2 reveals Mn(II) center to assume centrosymmetric octahedral geometry with an MnN₆ chromophore ligated by six N atoms of the six imH unit. The mononuclear units in 2 are engaged in N-H…O and C-H…O hydrogen bondings leading to a 2D sheet structure in ac plane. Complexes 1 and 2 display intraligand ¹ (π-π*) fluorescence at room temperature

Synthesis, structure and luminescence behaviour of zinc(II) complexes containing hexadentate N-donor Schiff bases

2427-2432Six hexacoordinated zinc(II) complexes of the type [Zn(L)](Y)2 [L = N-(1-pyridin-2-yl-formylidene)-N'-[2-({2-[(1-pyridin-2-ylformylidene)amino]ethyl}amino)ethyl]ethane- 1,2-diamine (pfad), Y = ClO4 (1a), Y = PF6 (1b); L = N-(1-pyridin-2-ylmethylidene)-N'-[2-({2 -I(1-pyridin-2-ylmethylidene)amino)ethyl]amino)ethyl)ethane- 1,2-diamine (pmad), Y = ClO4ˉ (2a), Y= PF6- (2b); L = N-(l-pyridin-2-ylbenzylidene)-N'-[2-({2-[(l-pyridin-2 ylbenzylidene)amino]-ethyl]amino)ethyl]ethane- 1,2-diamine (pbad), Y = ClO4ˉ (3a), Y = PF6- (3b)] have been synthesised and characterized on the basis of microanalytical, spectroscopic and other physicochemical properties. Structural analysis of 3a reveals that zinc(II) adopts a distorted octahedral environment with a ZnN6 chromophore ligated by two pyridine N atoms (N1, N1*), two imine N atoms (N2, N2*) and two amine N atoms (N3, N3*) in cis-trans-cis orientation. Spectral properties show that the other complex ions are iso-structural with the dication in 3a.</b

Osmium azo oxime chemistry. Facial tris chelate and trinuclear OsMOs species

This article does not have an abstract