The Electrochemical Investigation of MEH-PPV in Ionic Liquid

Ionic liquids are a new kind of room-temperature molten organic salts. It can be used as solvents in the organic/polymeric syntheses, and some of them are called "green" solvents because of its recyclability1. Ionic liquids possess the superior properties, such as thermal stability up to 200(C, involatility and re-designability(for both cation and anion). The ionic liquid employed in this work is [bmim] [PF6]- ( butylmethylimidazolium hexafluorophosphate ) which is immiscible with water and h…     

Synthesis,crystal structures and electrochemical properties of group 6 metal carbonyl anion complexes

A series of [M(CO)₅I]⁻ and [M₂(CO)₁₀I]⁻ anion complexes have been synthesized by the photochemical reaction of PhCH₂N(CH₃)₃I or FcCH₂N(CH₃)₃I (Fc=ferrocenyl) with M(CO)₆ (M = Cr, Mo or W), and characterized by elemental analyses, i.r., ¹H-n.m.r. and ¹³C-n.m.r. spectra in the case of the molybdenum and tungsten complexes. These complexes exhibit considerably different electrochemical behavior, when investigated by cyclic voltammetry. The crystal structures of [PhCH₂N(CH₃)₃][Cr(CO)₅I] and [FcCH₂N(CH₃)₃][W₂(CO)₁₀I] have been determined by X-ray diffraction, indicating that only weak contacts maybe exist between anions and cations by the I...H bond in the former, and there are no direct interactions between anions and cations in the latter.     

Transition metal complexes with Girard reagent-based ligands

The ligand, salicylaldehyde Girard-T hydrazonium chloride, [H₂SalGT]Cl (1), and two complexes [Cu(HSalGT)X₂]·H₂O (X = Br(2); Cl(3)) were synthesized and their crystal structures were determined by single-crystal X-ray analysis. In the two isostructural complexes, the Cu(II) is located in a square-pyramidal environment, with the chelating ligand and one halogen atom in the basal plane and the second halogen in the apical position. The most apparent structural difference between the 1 and its complexes 2 and 3 is the orientation of the N(CH₃)₃ group: in 1, it is practically coplanar to the rest of the molecule, while in 2 and 3 it is oriented to the side of the axially bonded halogen, which can be explained by the C–H…X intramolecular interactions. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and electronic absorption spectra.     

Thermal behaviour and firing characteristics of Zr/KClO4 primer mixture containing CuO

The effect of CuO on the thermal behaviour of Zr/KClO₄ primer mixtures was studied by thermoanalytical techniques, and the Bruceton method and its related calculation. It was found that the CuO catalytically promoted the decomposition of Zr/KClO₄ primer mixtures and shifted the exothermic peak of DSC curves to lower temperatures. In addition, the Zr/KClO₄ primer mixture containing CuO had a significant effect on the firing characteristics of electro-explosive devices.     

Synthesis,crystal structure and ferro-magnetic interaction of a binuclear copper(II) complex with the 1,4-dinitro-2,3,5,6-tetracarboxylatobenzenic anion as bridging ligand

A binuclear complex [Cu₂(DTB)(DMF)₄(H₂O)]·2DMF (DTB = 1,4-dinitro-2,3,5,6-tetracarboxylatobenzenic anion; DMF = N,N-dimethylformamide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex Cu ion is located in a distorted square pyramidal environment with two oxygen atoms O(1) and O(3) from two carboxylate groups, another two oxygen atoms O(7) and O(8) from terminal ligands of two DMF molecules, and a fifth coordinated oxygen atom O(9) from the terminal ligand of one H₂O molecule, in which the O(8) atom is situated in the apex of the pyramid. DTB as bridging ligand coordinates two Cu ions through its four carboxylate groups. The variable-temperature magnetic susceptibility of the complex was measured in the 5–300 K range. The magnetic coupling parameter is consistent with a ferromagnetic exchange between the two copper(II) centers and the data fit a binuclear magnetic exchange model based on the Hamiltonian operator ( = -2J₁₂, ₁ = ₂= 1/2), giving the ferromagnetic coupling parameter of 2J = 1.80 cm^{- 1}. This is the first example of a tetracarboxylatobenzenic bridging complex exhibiting ferromagnetic interaction.     

Reactions of sulfur(IV) with an octahedral manganese(IV) complex of 1,8-bis(2-hydroxy benzamido)-3,6-diaza octane: the role of phenolate–amide–amine coordination

The Mn^IV complex of tetra-deprotonated 1,8-bis(2-hydroxybenzamide)-3,6-diazaoctane (Mn^IVL) engrossed in phenolate-amido-amine coordination is reduced by HSO₃⁻ and SO₃²⁻ in the pH range 3.15–7.3 displaying biphasic kinetics, the Mn^IIIL⁻ being the reactive intermediate. The Mn^IIIL⁻ species has been characterized by u.v.–vis. spectra {λ _max, (ε, dm³ mol⁻¹ cm⁻¹): 285(15 570), 330 sh (7570), 469(6472), 520 sh (5665), pH=5.42}. SO₄²⁻ was the major oxidation product of S^IV; dithionate is also formed (18 ± 2% of [Mn^IV]_T) which suggests that dimerisation of SO₃^−• is competitive with its fast oxidation by Mn^IV/III. The rates and activation parameters for Mn^IVL + HSO₃⁻ (SO₃²⁻) → Mn^IIIL⁻; Mn^IIIL⁻ + HSO₃⁻ (SO₃²⁻) → Mn^IIL²⁻ are reported at 28.5–45.0 °C (I=0.3 mol dm⁻³, 10% (v/v) MeOH + H₂O). Reduction by SO₃²⁻ is ca. eight times faster than by HSO₃⁻ both for Mn^IVL and Mn^IIIL⁻. There was no evidence of HSO₃⁻/SO₃²⁻ coordination to the Mn centre indicating an outer sphere (ET) mechanism which is further supported by an isokinetic relationship. The self exchange rate constant (k₂₂) for the redox couple, Mn^IIIL⁻/Mn^IVL (1.5 × 10⁶ dm³ mol⁻¹ s⁻¹ at 25 °C) is reported.