Highly robust tetrazolate based complexes for efficient and long-term stable dye sensitized solar cells
作者:Tharallah A. Shoker、Ralph Tanios、Remi Fayad、Tarek H. Ghaddar
DOI:10.1039/c5ra11984g
日期:——
We report a new family of RuII complexes that bear tetrazolate based ligands with superb long-term stability.
我们报道了一种新的RuII配合物家族,其搭配四唑基配体,具有极好的长期稳定性。
Synthesis and properties of some novel nonionic polyol surfactants
作者:Catherine B. A. Briggs、Ian M. Newington、Alan R. Pitt
DOI:10.1039/c39950000379
日期:——
A homologous series of nonionic surfactants 4 based on sugar lactones has been synthesised and evaluated.
我们合成并评估了基于糖内酯的同源系列非离子表面活性剂 4。
Phase transfer catalysis of heterogeneous reactions by quaternary salts
申请人:Continental Oil Company
公开号:US03992432A1
公开(公告)日:1976-11-16
A process for catalyzing heterogeneous ionic organic reactions in a system of multiple liquid phases in which at least two of the reactants are each located in a different phase with respect to the other, the phases containing such reactants differing in polarity. Catalysis is effected by introducing to the system one of certain organic quaternary salts which are more soluble in the least polar reactant-containing phase than in the other reactant-containing phases. The quaternary salt catalysts utilized have the general structural formula (AM).sup.+X.sup.- where A is an organic portion of the salt molecule bonded to M by four covalent linkages, and preferably comprises a plurality of hydrocarbon radicals of either monovalent or polyvalent character, M is selected from the group consisting of nitrogen, phosphorus, arsenic, antimony and bismuth, and X.sup.- is an anion which will dissociate from the cation (AM).sup.+ in an aqueous environment, and is preferably selected from the group consisting of halogen and hydroxyl anions.
Realization of the synthesis of α,α-disubstituted carbamylacetates and cyanoacetates by either enzymatic or chemical functional group transformation, depending upon the substrate specificity of Rhodococcus amidase
Substrate specificity and enantioselectivity of nitrile hydratase and amidase from R. rhodochrous IFO 15564 has been studied by applying a series of alpha,alpha-disubstituted malononitriles and related substrates. The amidase preferentially hydrolyzed the pro-(R) carbamyl group (amide) of the prochiral diamides, an intermediate resulting from the action of nitrile hydratase in a nonenantiotopic group-selective manner. The introduction of a fluorine atom at the alpha-position caused an inhibitory effect on amidase. By a combination of this microbial transformation and the subsequent Hofmann rearrangement, an important precursor of (S)methyldopa with 98.4% ee has been prepared. For the enzymatically poor substrate, the action on HO3SONO-H2O on the carbamyl group was effective, leaving the cyano group intact. This conversion is demonstrated as the key step for the expeditious preparation of (+/-)-alpha-cyano-alpha-fluoro-alpha-phenylacetic acid (CFPA) from diethyl alpha-fluoro-alpha-phenylmalonate. (C) 2004 Elsevier Ltd. All rights reserved.