Synthesis and Structure of a New Dimanganese Complex [Mn2(μ-OAc)2(phen)4](ClO4)2

A dinuclear manganese(II) complex, [Mn2(μ-Oac)2(phen)4](ClO4)2 1 (phen = phenanthroline), has been prepared by the reaction of Mn(Oac)2·4H2O, phen, tartaric acid and NaClO4·H2O in MeOH/H2O solution. The crystal structure has been determined by X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 9.6052(4), b = 14.2353(7), c = 18.8893(8)(A),β= 96.584(1)°, C52H38Cl2Mn2N8O12, Mr = 1147.68, V = 2565.8(2) (A)3, Dc = 1.486 g/cm3, F(000) = 1172, μ = 0.668 cm-1 and Z = 2. The final refinement gave R = 0.0605 and wR = 0.1619 for 3203 reflections with I > 2σ(I). The complex contains a dinuclear [Mn2(μ-Oac)2(phen)4]]2+ cation located at a centre of symmetry with two syn-anti acetate bridges between the Mn atoms. Each Mn atom is coordinated by four N atoms from two chelating phen ligands and two O atoms from a pair of bridging acetate groups to furnish a distorted octahedral geometry. Two ClO4 anions exist around the cation [Mn2(μ-Oac)2(phen)4]2+as counter ions.     

Preparation of light-stable micelles with azo dyes from a nonamphiphilic random block copolymer

Light-stable micelles with azo dyes were prepared by micelle formation of a nonamphiphilic diblock copolymer containing azobenzene and UV absorbent at ca. 1 mol% as the unit ratios. The nonamphiphilic block copolymer consists of two different kinds of random copolymer blocks: poly[4-(phenylazophenoxymethyl)styrene-co-vinylphenol] (P(AS-co-VPh)) and poly[4-(2-hydroxybenzophenoxymethyl)styrene-co-styrene] (P(HBS-co-St)). This random block copolymer, P(AS-co-VPh)-b-P(HBS-co-St) formed the micelles in the presence of 1,4-butanediamine (BDA) through hydrogen bond cross-linking between the VPh units via BDA. The micelles had the azobenzene moieties at the cores and the UV absorbents at the coronas. The micelles showed a small color difference in color fading experiments, in comparison with the unimers and with micelles having no UV absorbent at the coronas. It is significant that the diblock copolymer forms the micelles and has the UV absorbents at the coronas to suppress the color fading. Furthermore, the chain length of ,-diamines had no effect on the hydrodynamic radius of the micelles, but affected the aggregation number and the cmc.     

Synthesis of Fullerene-Acrylamide Copolymer Nanoball and Its Lubrication Properties

A novel fuUerene-acrylamide copolymer was synthesized via radical polymerization. It is soluble in polar solvents such as water, dimethyl sulfoxide etc. The product was characterized by FTIR, UV-Vis and GPC. TEM analysis shows that the average particle diameter is about 46 nm. Four-ball tests show that the addition of a certain concentration of the fullerene copolymer to base stock (2 wt% triethanolamine and 0.5 wt% OPZ aqueous solution) can effectively raise the load-carrying capacity (PB value) and the antiwear ability. SEM analysis shows that the addition results in reducing diameter of wear scar and decreasing wear.     

含规整聚环氧乙烷枝链的聚硅氧烷的合成及表征

以萘钾为引发剂，二甲基亚砜为溶剂制备了以烯丙基为末端基的聚环氧乙烷大单体，并利用末端双键的硅氢化反应合成了相对分子质量规整的聚环氧乙烷接枝聚硅氧烷的共聚物。产物经萃取精制后，用ＩＲ、￣１ＨＮＭＲ等方法进行了表征。     

Development of a novel potentiometric titration method for determination of polypropylene degradation

In this study, a novel potentiometric titration of hydroperoxide in degraded polypropylene (PP) is proposed. This titration is quite sensitive compared with the conventional ones such as UV and manual titrations, and its detection limit was about 2 meq/kg. The sensitivity was equal to that of molecular weight measurement by GPC for the degraded PP and, in addition, the volatilization behavior of the hydroperoxide could be detected. This titration was found to be very effective for the determination of PP degradation.     

MONTE CARLO SIMULATION OF TRIBLOCK COPOLYMER/HOMOPOLYMER BLEND FILMS

1. INTRODUCTION The extensive applications of block copolymer have been studied in detail due to their special molecular architecture and characteristic [1,2]. Recently, many studies including theoretical analysis and experimental techniques have addressed the polymer blend system of diblock copolymer/homopolymer [3~9]. An early investigation presented a quantitative analysis of homopolymer distributions in well-ordered copolymer microdomains through mixing polystyrene (PS) or poly methyl…     

New transformations of vinyl acetate under the influence of the complex Rh(PPh3)3Cl

The strictly regioselective hydrocarboxylation of vinyl acetate to ethylidene diacetate by acetic acid formed in situ from vinyl acetate was realized for the first time with Rh(PPh₃)₃Cl as catalyst. The transformation of vinyl acetate into benzene, acetophenone, and acetylene was also realized.Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, 420083 Ufa. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1406–1408, June, 1992.     

Novel polymer blends based on poly(ether-urethane) ionomer and ion-containing styrene copolymer

The structure-property relationships of thermoplastic polymer blends based on poly(ether-urethane) ionomer (PEUI) and ion-containing styrene-acrylic acid copolymer (S-co-AA(K)) have been investigated by using DMTA, DSC and TGA, as well as tensile tests. Convergence of the glass transition temperature (T_g) values of the PEUI and the S-co-AA(K) components in the blends studied, as compared to the individual polymers, was found and explained by improving compatibility of the components due to increasing effective density of physical networks formed by ion-dipole and ion-ion interactions of ionic groups of the components. Character of E'=f(T) and E'=f(T) dependencies confirms the increase of the effective density of physical networks in the compositions studied compared to individual PEUI and S-co-AA(K). Improvement of end-use properties, i.e. thermal stability and tensile properties has been found for the PEUI/S-co-AA(K) compositions with lower content of S-co-AA(K) (i.e. <10 mass%) and explained by formation of additional network of intermolecular ionic bonds between the functional groups of PEUI and S-co-AA(K).     

Freezing temperatures of aqueous solutions of methyl formate and ethyl acetate with a variety of nonelectrolytes. Gibbs energy of interaction of the ester group with other functional groups

Freezing temperatures of dilute aqueous solutions of ethyl acetate and mixtures with myo-inositol, D-mannitol, formamide, 1,3,5-trioxane, 1,4-dioxane, acetamide, hexamethylenetetramine, and methyl formate have been measured. In addition, freezing temperatures of dilute aqueous solutions of methyl formate and mixtures with the above solutes have been measured. From these data, the pairwise molecular Gibbs energies of interaction between the molecules were calculated. Using the additivity principle, the pairwise functional group Gibbs energies of interaction were calculated for ester group interactions with a variety of other functional groups.     

负载锰卟啉催化乙酰胆固醇的选择性环氧化

多相金属卟啉催化剂已经被用于普通烯烃的环氧化,如表面修饰的多孔分子筛(MCM 41)[1 3],本文制备了高分子负载型锰卟啉用作胆固醇的非对映选择性环氧化催化剂。转化率可达100%,β选择性可达99%。1　实验部分乙酰胆固醇按文献[4]合成。溶剂均为AR级,按文献方法纯化。将Merrifield sPeptideresin(Aldrich,2%,交联度,200-400目,≈2mmolCl/g)加入到精制的DMF中,室温下放置24h,加入5-(对羟基苯基)-10,15,20-三(对甲基苯基)卟啉及无水K2CO3,N2保护下,80℃反应6h,洗涤干燥得到催化剂[1](图1)。催化环氧化反应　将PhIO及催化剂按化学计…