Effect of pendent group structures on the chemical selectivity and performance of sulfonated copolymers as novel pseudophases in electrokinetic chromatography

Amphiphilic copolymers of 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) with dihydrocholesteryl acrylate (pDHCHAt) or tert-octyl acrylamide (ptOAm) as comonomers were synthesized, characterized and used as new polymeric pseudostationary phases in electrokinetic chromatography. High-efficiency separations with theoretical plates around 500,000 to 870,000/m were achieved. Linear solvation energy relationships analysis of 20 solutes was performed to investigate the retention mechanism. Polycyclic aromatic hydrocarbons (PAHs) were separated under 30% v/v acetonitrile. The separation of nine aromatic model solutes by pDHCHAt showed significantly different selectivity from that of sodium dodecyl sulfate. Although only minor difference in selectivity was found for small aromatic compounds on pDHCHAt and poly(AMPS-lauryl acrylate), significantly different retention mechanism was found for PAHs and n-dodecanophenone comparing both copolymers. Significant chemical selectivity difference was found for selected small aromatic compounds on ptOAm and poly(AMPS-stearyl acrylamide).     

Highly enantioselective epoxidation of alpha,beta-unsaturated esters by chiral dioxirane

This paper describes a highly enantioselective epoxidation of alpha,beta-unsaturated esters using the fructose-derived ketone 2 as catalyst and Oxone as oxidant. High ee's have been obtained for a number of trans and trisubstituted substrates (82-98% ee). The results described show that it is feasible for dioxiranes to effectively epoxidize electron-deficient olefins with high ee's.     

硫杂杯芳烃--一类新型的分子受体化合物

综述了近年来一类新型分子受体化合物——硫杂杯芳烃及其衍生物的合成、受体化学以及应用方面的研究进展。     

Michael-Addition Reaction of Malononitrile with α,β-Unsaturated Cycloketones Catalyzed by KF／Al2O3

A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and α,β-unsaturated cycloketones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen-1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80℃, 2-amino-3-cyano-4-aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the α,β-unsaturated ketones were replaced by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino-3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.     

Applications of homemade kit in mutation detection of genes

With the accomplishment of Human Genome Project (HGP), single nucleotide polymorphism (SNP) and mutation detection in human genome are becom-ing a new researching focus. These researches can help us to understand the phenotype diversity of indi-vidual, disease susceptibility and drug resistance of different colonies. Traditional method used for muta-tion detection is slab gel electrophoresis, which re-mains labor-intensive and time-consuming because of the requirement of radioactivity or te…     

C-C bond cleavage of acetonitrile by a dinuclear copper(II) cryptate

The dinuclear copper(II) cryptate [Cu2L](ClO4)4 (1) cleaves the C-C bond of acetonitrile at room temperature to produce a cyanide bridged complex of [Cu2L(CN)](ClO4)3.2CH3CN.4H2O (2). The cleavage mechanism is presented on the basis of the results of the crystal structure of 2, electronic absorption spectra, ESI-MS spectroscopy, and GC spectra of 1, respectively.     

Adenanthusone,a New Ursane Type Nortriterpenoid from Isodon adenanthus

A new ursane‐type nortriterpenoid, adenanthusone (=(11α,12α)‐4‐demethyl‐11,12‐epoxy‐3,13‐dihydroxy‐2‐oxoursa‐3,20(30)‐diene‐28‐oic acid γ‐lactone; 1 ) was isolated from Isodon adenanthus. Its structure was determined by NMR spectra and X‐ray crystallographic diffraction analysis. The biogenetic implication of the nortriterpene is discussed.     

Structure and Magnetic Properties of a Novel Two‐Dimensional Complex from 1, 3, 5‐Benzenetricarboxylate and Neodymium(III) — {[Nd(1, 3, 5‐benzenetricarboxylate)(H2O)4] · H2O}n

A unique neodymium(III) complex, {[Nd(BTC)(H₂O)₄] · H₂O}_n (BTC = 1, 3, 5‐benzenetricarboxylate), was obtained from the reaction between Nd(ClO₄)₃ · xH₂O and Na₃BTC. Coordination bonds, hydrogen bonds, and π‐π stacking form a supramolecular structure with a novel, two‐dimensional framework. The temperature‐dependent magnetic susceptibilities were analyzed by the Curie‐Weiss law; the following values were found C = 1.32, θ = —18.3 K, respectively.     

Bis[1,1‐di­methyl­biguanide(1–)‐κ2N2,N5]copper(II) monohydrate

The crystal structure of the title compound, [Cu(C₄H₁₀N₅)₂]·H₂O, contains two independent copper N,N‐di­methyl­biguanide complex units, each with square‐planar coordination of the Cu atom by four N atoms. The two complexes have different symmetry, with one Cu atom lying on an inversion centre and the other on a twofold rotation axis. The Cu—N bond lengths are 1.923 (2) and 1.950 (2) Å in the centrosymmetric complex, and 1.928 (2) and 1.938 (2) Å in the non‐centrosymmetric complex. The crystal structure is stabilized by N—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds; each water mol­ecule forms four hydrogen bonds involving three different Cu complexes.     

Poly­[[bis­[aqua(1,10‐phenanthroline)­lanthanum(III)]‐μ‐aqua‐di‐μ‐5‐sulfonatoisophthalato] monohydrate] and poly­[[[tri­aqua­lanthanum(III)]‐μ‐5‐sulfonatoisophthalato] monohydrate]

In the two related polymeric title compounds, {[La₂(sip)₂(phen)₂(H₂O)₃]·H₂O}_n [sip is the 5‐sulfonatoisophthalate trianion (C₈H₃O₇S³⁻) and phen is 1,10‐phenanthroline (C₁₂H₈N₂)], (I), and {[La(sip)(H₂O)₃]·H₂O}_n, (II), the lanthanum(III) ions are nine‐coordinate, with similar distorted monocapped square‐antiprism coordination geometry. The two crystal structures are very different. In (I), the sip anion acts as a pentadentate ligand, one of the coordinated water mol­ecules lies on a twofold axis and further inversion, n‐glide and translation operations generate a two‐dimensional framework. In (II), the sip anion functions as a hexadentate ligand and a three‐dimensional network with trinuclear 24‐membered rings is developed via inversion, n‐glide, twofold‐screw and translation operations. Both structures also have extensive O—H⋯O hydrogen‐bonded networks and π–π interactions.