Synthesis,Crystal Structure,Spectroscopic Characterization,Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex

A new copper（Ⅱ） complex [Cu2（MNA）2（2,2‘-bipy）2]·2.5H2 O with methy-5-norbornene-2,3-dicarboxylic acid（MNA） and 2,2’-bipyridine as ligands has been synthesized in the mixed solvents of DMF and water.It crystallizes in monoclinic,space group P 1,with a = 10.4191（11）,b = 12.8883（13）,c = 16.1114（16） A,α = 70.8090（10）,β = 80.568（2）,γ = 77.440（2）o,V = 1984.3（4） A^3,Dc = 1.551 g/cm^3,Z = 2,F（000） = 962,the final GOOF = 1.051,R = 0.0431 and w R= 0.0980.The crystal structure shows that the whole molecule consists of two independent dinuclear units,in which two copper ions are bridged by two μ2-η^1：η^0 3-carboxylate groups of MNA^2-.The coordination environment of Cu（Ⅱ） ion is Cu O3N2,giving a distorted square pyramidal geometry.The spectroscopic characterization,thermal stability and magnetic properties of the complex were investigated.

Synthesis and Spectroscopic Characterization of Compounds of Lanthanide-2,4-Pentanedionates with Pyridine

Compounds of the formula [Ln(pd)_3(py)_2] where Ln=La～Yb and Y except Pm and Tin,Hpd (=2, 4-pentanedione) and py (=pyridine) have been synthesised and characterised by physical and spectral studies. Pyridine is coordinated in all the compounds.The covalency parameters β,b^(1/2),δ and η indicate at least some covalency in these compounds.The compounds have been checked for their use as NMR shift reagents using cholesterol as substrate.Eight coordinate compounds increase their coordination number when added to the substrate.

Spectroscopic Characterization of Staphylococcal Nuclease Mutants with Tryptophan at Internal Sites

Tryptophan （Trp） is an intrinsic fluorescent probe for detecting the site-specified dynamics inside/outside protein. It is found that the Trp can easily be inserted in desired sites of protein, which affects the integrity of the overall structure. To evaluate this effect, we design thirteen double point mutants of staphylococcal nuclease, each of which has a single Trp residue planted at an internal site. The studies on Trp fluorescence, ANS-binding fluorescence, far- and near-UV CD spectra, and enzymatic activity are carried out. It is found that the mutation at the hydrophobic core of protein generates molten globular state conformation, which is a loose structure compared to their original compactness in wild type （WT）. Its enzyme activity and surface hydrophobicity are also affected. The studies show that by proper site designing and external binding, Trp mutagenesis is a suitable method for carrying out the study on site specified dynamics of proteins.

Synthesis,Crystal Structure,Spectroscopic Characterization and Thermal Stability Properties of a Trinuclear Zinc(Ⅱ) Complex

A new trinuclear zinc complex Zns（2,2＂-bipy）2（3,5-DMBA）6＂（H20）1.5 （1） with 3,5-dimethylbenzoic acid （3,5-DMBA） and 2,2＂-bipyridine as ligands has been synthesized in the mixed solvents of methanol and water. It crystallizes in the monoclinic space group C2/c with a = 31.1497（15）, b = 11.7576（6）, c = 20.9049（10） A, fl = 118.4550（10）°, V- 6731.4（6） A3, Dc = 1.412 g/cm3, Z = 4, F（000） = 2972, GOOF = 1.069, the final R= 0.0667 and wR= 0.1917. The whole molecule consists of three zinc ions, six 3,5-DMBA molecules, two 2,2＂-bipyridine molecules and one and half water molecules, in which three zinc ions are bridged by six μ2-η1：η0 carboxylate groups of 3,5-DMBA. The Zn（1） atom is centrosymmetric, and adopts a distorted octahedral ZnO6 geometry, while the Zn（2） gives a distorted square pyramidal ZnOsN2 geometry. The spectroscopic characterization and thermal stability properties of the complex were investigated.

Spectroscopic Characterization of Mo-Co-S and Mo-Fe-S Complexes-derived Catalysts for Desulfurization and Denitrification

The characteristic studies, by means of LR, UV-Vis and XPS spectroscopies, of the preparation process of Mo-Co-S and Mo-Fe-S catalysts for HDS and HDN, derived from (NH4)2MoS4-CoCl2 and (NH4)2MoS4-FeCl2 complexes supported on γ-Al2O3, respectively, indicate that the catalytically essential moiety on the surface of the catalysts is dominantly some sulfido-bimetallic species with such a structural unit (M' =Co or Fe), and both Co and Fe, served as promoters, can donate electrons to Mo probably via bridging-S. The nature of active-sites and the mechanism of promotion are discussed according to the results.

Synthesis and spectroscopic characterization of cobalt porphyrins and their catalytic activity towards dioxygen reduction

The synthesis and spectroscopic characterization of cobalt(Ⅱ) 5-(4-pyridyl)-10,15,20-triphe- nylporphyrin,cobalt(Ⅱ) 5-(4-N-hexadecylpyridiniumyl)-10,15,20-triphenylporphyrin bromide and cobalt(Ⅱ) 5-(2-aminophenyl)-10,15,20-triphenyl-porphyrin are reported.The corresponding copper and vanadyl derivatives ((TriP)Cu,[(hTriP)Cu]^+Br^- and [(hTriP)VO]^+Br^-) were also studied.Each metalloporphyrin was characterized by UV-visible,ESR and ~1H NMR spectroscopy.These me- talloporphyrins can be firmly adsorbed on the glassy carbon (GC) surface.The catalytic reduction of dioxygen at GC electrodes modified by these catalysts was studied by cyclic voltammetry (CV).The kinetic process of dioxygen reduction at the cobalt porphyrin-modified electrodes was studied with a rotating ring disk electrode.

Synthesis and Characterization of Tetravalent Cerium Complexes with p-Tert-butylcalix[n]arenes (n=4, 6, 8)

Three Ce 4+ complexes Ce(p tert butylcalixarene)·(dmf) 4·H 2O (complex A), Ce(p tert butylcalixarene) 2·(dmf) 10 (complex B) and Ce(p tert butylcalixarene)·(dmf) 4 (complex C) were prepared from N,N dimethylforamide (dmf) solution of Ce(NO 3) 3. Their thermal stability, optical properties and coordination features were investigated with thermogravimetric and differential thermal analysis, ultraviolet and visible spectrophotometer, fluorescence spectrophotometer, infrared spectroscopy, and 1H NMR spectrometer. In the solvents of C 6H 6, 1,2 dichloroethane and dmf, complexes A and B can exhibit a ligand to metal charge transfer transition lying in ca. 20000 cm -1 in the electronic spectra. Complex A displays a dimeric structure in C 6D 6 solution. Ce 4+ ions in the complexes are coordinated by phenolic groups of the ligands, oxygen atoms of dmf molecules, and / or OH - ions.

Oxygen-Containing Functional Groups Regulating the Carbon/Electrolyte Interfacial Properties Toward Enhanced K^(+)Storage

Oxygen-containing functional groups were found to e ectively boost the K^(+)storage performance of carbonaceous materials,however,the mechanism behind the performance enhancement remains unclear.Herein,we report higher rate capability and better long-term cycle performance employing oxygen-doped graphite oxide(GO)as the anode material for potassium ion batteries(PIBs),compared to the raw graphite.The in situ Raman spectroscopy elucidates the adsorption-intercalation hybrid K^(+)storage mechanism,assigning the capacity enhancement to be mainly correlated with reversible K^(+)adsorption/desorption at the newly introduced oxygen sites.It is unraveled that the C=O and COOH rather than C-O-C and OH groups contribute to the capacity enhancement.Based on in situ Fourier transform infrared(FT-IR)spectra and in situ electrochemical impedance spectroscopy(EIS),it is found that the oxygen-containing functional groups regulate the components of solid electrolyte interphase(SEI),leading to the formation of highly conductive,intact and robust SEI.Through the systematic investigations,we hereby uncover the K^(+)storage mechanism of GO-based PIB,and establish a clear relationship between the types/contents of oxygen functional groups and the regulated composition of SEI.

Miscibility of Two Components in a Binary Mixture of 9-Phenyl Anthracene Mixed with Stearic Acid or Polymethyl Methacrylate at Air-Water Interface

We report the miscibility characteristics of two components in a binary mixture of 9-phenyl anthracene （PA） mixed with stearic acid （SA） or polymethyl methacrylate （PMMA）. The behaviour of surface pressure versus area per molecule isotherms reveal that the area per molecule decreases systematically with increasing molefractions of PA. The characteristics of areas per molecule versus molefractions and collapse pressure vs molefraction indicate that various interactions involved among the sample and matrix molecules. The interaction scheme is found to change with the change in surface pressure and molefraction of mixing. Scanning electron microscopic study confirms the aggregation of PA molecules in the mixed films.