نتایج جستجو برای: strained molecules

تعداد نتایج: 198218  

Mehdi Nabati, Mehrdad Mahkam, Yaser Gholizade Atani

Tetrahedrane is most strained and the smallest cage compound. It attracts organic chemists because ofits unusual bonding nature and highly symmetrical structure. However, many efforts to isolate theparent tetrahedrane have been unsuccessful because of the high reactivity and very short lifetimecaused by the strain in this molecule. Modeling of molecules for determination of structuralproperties...

Journal: :The journal of physical chemistry. A 2007
Peng Bao Zhong-Heng Yu

At RHF, MPn, and DFT levels, a procedure of geometry optimization under the restrictions of pi-orbital interactions (GOR) was developed, thus providing a conjugated molecule with the following two types of localized reference geometries: a "GL" geometry where all double bonds are localized, and n different "GE-n" geometries, in each of which only two double bonds were permitted to conjugate. In...

Journal: :journal of food quality and hazards control 0
s. mason school of biology, faculty of biological sciences, university of leeds, leeds, uk s. arjmandtalab deputy of food and drug control, shiraz university of medical sciences, shiraz, iran b. hajimohammadi research center for food hygiene and safety, shahid sadoughi university of medical sciences, yazd, iran m.h. ehrampoush department of environmental health, faculty of health, shahid sadoughi university of medical sciences, yazd, iran a. khosravi arsanjani [email protected] g.h. jahed khaniki department of environmental health, faculty of health, tehran university of medical sciences, tehran, iran

background: aflatoxin m1 (afm1) is a toxic compound that could be found in milk and dairy products. afm1 is the principle hydroxylated derivative of aflatoxin b1 (afb1), formed in liver and excreted into the milk in the mammary glands of both human and lactating animals that have been fed with afb1 contaminated diet. to the best of our knowledge, there is no report on stability of afm1 during p...

Hassan Kabiri-Fard Issa Yavari

Ab initio calculation at HF/6-31G* level of theory for geometry optimization and MP2/6-31G*//HF/6-31G* for a single point total energy calculation are reported for the important energyminimumconformations and transition-state geometries of of cyclodeca-1,2,3-triene (1). The mostfavorable conformation of 1 is a unsymmetrical twist-chair (1-TC) structure. Degenerateinterconversion of 1-TC with it...

Journal: :Angewandte Chemie 2021

A novel stable donor/acceptor-supported MnI-metallasilanone 3 was synthesized. The intramolecular silanone-MnI interaction induces a highly strained three-membered cyclic structure, leading to an exceptionally high reactivity of as donor/acceptor complex silanone. Indeed, metallasilanone readily reacts with various small molecules such H2 or ethylene gas in mild conditions.

Journal: :journal of physical and theoretical chemistry 0
mehdi nabati chemistry department, faculty of science, azarbaijan shahid madani university, tabriz, iran mehrdad mahkam chemistry department, faculty of science, azarbaijan shahid madani university, tabriz, iran yaser gholizade atani mathematics department, faculty of science, azarbaijan shahid madani university, tabriz, iran

tetrahedrane is most strained and the smallest cage compound. it attracts organic chemists because ofits unusual bonding nature and highly symmetrical structure. however, many efforts to isolate theparent tetrahedrane have been unsuccessful because of the high reactivity and very short lifetimecaused by the strain in this molecule. modeling of molecules for determination of structuralproperties...

2011
David Garayalde Cristina Nevado

The development of new methodologies catalyzed by late transition metals involving cycloisomerizations of strained rings can open new venues for the synthesis of structurally complex molecules with interesting biological activities. Herein we summarize, from both a synthetic as well as a mechanistic point of view, the most recent developments in gold-catalyzed ring expansions.

2015
Katherine A Horner Nathalie M Valette Michael E Webb

Strain-promoted inverse electron-demand Diels-Alder cycloaddition (SPIEDAC) reactions between 1,2,4,5-tetrazines and strained dienophiles, such as bicyclononynes, are among the fastest bioorthogonal reactions. However, the synthesis of 1,2,4,5-tetrazines is complex and can involve volatile reagents. 1,2,4-Triazines also undergo cycloaddition reactions with acyclic and unstrained dienophiles at ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده فنی 1389

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