Interplay of Olefin Metathesis and Multiple Hydrogen Bonding Interactions: Covalently Cross-linked Zippers
摘要:
Hydrogen-bonded zippers bearing terminal alkene groups were treated with Grubbs' catalyst, leading to covalently cross-linked zippers without violating H-bonding sequence specificity. The yield of a cross-linked zipper depended on the stability of its H-bonded precursor, with a weakly associating pair giving reasonable yields only at high concentrations while strongly associating pairs showed nearly quantitative yields. The Integration of thermodynamic (H-bonding) and kinetic (irreversible C=C bond formation) processes suggests the possibility of developing many different covalent association units for constructing molecular structures based on a self-assembling way.
Identification of liquid hydrocarbons using chemical markers
申请人:NALCO CHEMICAL COMPANY
公开号:EP0512404A1
公开(公告)日:1992-11-11
The present invention relates to a composition, a method for preparing a composition, and a method for analyzing the composition where the composition includes a liquid hydrocarbon and one or more marker compounds of formula (I):
where Y is selected from X-R² or NR³R⁴, and where X is an oxygen atom or a sulfur atom, R² is an organic radical having from about 1 to about 30 carbon atoms, R³ and R⁴ are the same or different organic radical having from about 1 to about 30 carbon atoms. The markers can be present in the amounts from about .05 parts per million to about 50 parts per million, preferably from about .05 to about 25 parts per million and preferably from about 1 to about 10 parts per million and is usable to identify not only the source and identity of the particular hydrocarbon liquid, but also to allow expedient tracing of the hydrocarbon back to its source and analysis of the particular types of additives that may be present and to what extent they are present in the hydrocarbon.
A Highly Stable, Six-Hydrogen-Bonded Molecular Duplex
作者:Huaqiang Zeng、Rebecca S. Miller、Robert A. Flowers、Bing Gong
DOI:10.1021/ja9942742
日期:2000.3.1
This paper describes the design, synthesis, and characterization of a hydrogen-bondedmolecularduplex (3·4). Two oligoamide molecular strands, 3 and 4, with the complementary hydrogen-bonding sequences ADAADA and DADDAD, respectively, were found to form an extremely stable (Ka = (1.3 ± 0.7) × 109 M-1) molecularduplex (3·4) in chloroform. Evidence from 1D and 2D 1H NMR spectroscopy, isothermal titration
Interplay of Olefin Metathesis and Multiple Hydrogen Bonding Interactions: Covalently Cross-linked Zippers
作者:Jisen Zeng、Wei Wang、Pengchi Deng、Wen Feng、Jingjing Zhou、Yuanyou Yang、Lihua Yuan、Kazuhiro Yamato、Bing Gong
DOI:10.1021/ol201282d
日期:2011.8.5
Hydrogen-bonded zippers bearing terminal alkene groups were treated with Grubbs' catalyst, leading to covalently cross-linked zippers without violating H-bonding sequence specificity. The yield of a cross-linked zipper depended on the stability of its H-bonded precursor, with a weakly associating pair giving reasonable yields only at high concentrations while strongly associating pairs showed nearly quantitative yields. The Integration of thermodynamic (H-bonding) and kinetic (irreversible C=C bond formation) processes suggests the possibility of developing many different covalent association units for constructing molecular structures based on a self-assembling way.