排序方式: 共有59条查询结果,搜索用时 31 毫秒
51.
[reaction: see text] Laser flash photolysis experiments, chemical trapping studies, and time-dependent density functional theory calculations demonstrate that photolysis of protonated 1,1-diarylhydrazines generates N,N-diarylnitrenium ions. 相似文献
52.
Results on the synthesis of silocanes and germocanes, eight-membered heterocycles with the general formula D(CH2CH2Z)2MXY are analyzed and classified. The chemical behavior of these compounds and the characteristics of the element-nitrogen
transannular bond are studied.
Dedicated to Prof. E. Lukevics on his 70th birthday.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1777–1825, December, 2006. 相似文献
53.
A. A. Selina S. S. Karlov E. Kh. Lermontova G. S. Zaitseva 《Chemistry of Heterocyclic Compounds》2007,43(7):813-834
Results on the synthesis of stannocanes-eight-membered heterocycles with the general formula D(CH2CH2Z)2SnXY-are reviewed and analyzed. The chemical behavior of the compounds is examined, and the nature of the transannular bond
is studied.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–991, July, 2007. 相似文献
54.
55.
Hafeesudeen Sahabudeen Haoyuan Qi Marco Ballabio Miroslav Poloij Selina Olthof Rishi Shivhare Yu Jing SangWook Park Kejun Liu Tao Zhang Ji Ma Bernd Rellinghaus Stefan Mannsfeld Thomas Heine Mischa Bonn Enrique Cnovas Zhikun Zheng Ute Kaiser Renhao Dong Xinliang Feng 《Angewandte Chemie (International ed. in English)》2020,59(15):6028-6036
Single‐layer and multi‐layer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the long‐range transport properties. Here we employ a surfactant‐monolayer‐assisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimine‐based 2D polymer (PI‐2DP) films with square and hexagonal lattices, respectively. The synthetic PI‐2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200 nm and large crystalline domains (100–150 nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PI‐2DP are investigated by time‐resolved terahertz spectroscopy. Typically, the porphyrin‐based PI‐2DP 1 film exhibits a p‐type semiconductor behavior with a band gap of 1.38 eV and hole mobility as high as 0.01 cm2 V?1 s?1, superior to the previously reported polyimine based materials. 相似文献
56.
Dr. Young J. Hong Sandra Irmisch Dr. Selina C. Wang Dr. Stefan Garms Prof. Jonathan Gershenzon Prof. Liansuo Zu Dr. Tobias G. Köllner Prof. Dean J. Tantillo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(40):13590-13600
Terpene synthases, as key enzymes of terpene biosynthesis, have garnered the attention of chemists and biologists for many years. Their carbocationic reaction mechanisms are responsible for the huge variety of terpene structures in nature. These mechanisms are amenable to study by using classical biochemical approaches as well as computational analysis, and in this study we combine quantum‐chemical calculations and deuterium‐labeling experiments to elucidate the reaction mechanism of a triquinane forming sesquiterpene synthase from chamomile. Our results suggest that the reaction from farnesyl diphosphate to triquinanes proceeds through caryophyllyl and presilphiperfolanyl cations and involves the protonation of a stable (?)‐(E)‐β‐caryophyllene intermediate. A tyrosine residue was identified that appears to be involved in the proton‐transfer process. 相似文献
57.
CdI2 has been purified using the zone-refining technique by giving 20 passes. Single crystals grown from the starting material showed arcing in the X-ray oscillation photographs whereas it is absent in the crystals grown from the zone refined material. These crystals are found to be of the 4 H type. DC conductivity studies were made on these crystals at various stages of purification. The surface morphology of these crystals have been studied using an optical microscope. 相似文献
58.
Selina Hollstein Philipp Erdmann Andreas Ulmer Dr. Henrik Löw Prof. Dr. Lutz Greb Prof. Dr. Max von Delius 《Angewandte Chemie (International ed. in English)》2023,62(26):e202304083
The dynamic covalent chemistry (DCvC) of the Si−O bond holds unique opportunities, but has rarely been employed to assemble discrete molecular architectures. This may be due to the harsh conditions required to initiate exchange reactions at silicon in aprotic solvents. Herein, we provide a comprehensive experimental and computational account on the reaction of trialkoxysilanes with alcohols and identify mild conditions for rapid exchange in aprotic solvents. Substituent, solvent and salt effects are uncovered, understood and exploited for the construction of sila-orthoester cryptates. A sharp, divergent pH-response of the obtained cages renders this substance class attractive for future applications well beyond host-guest chemistry, for instance, in drug delivery. 相似文献
59.
Carsten E. Seyfert Christoph Porten Dr. Biao Yuan Selina Deckarm Dr. Fabian Panter Dr. Chantal D. Bader Janetta Coetzee Felix Deschner Dr. Kamaleddin H. M. E. Tehrani Prof. Dr. Paul G. Higgins Prof. Dr. Harald Seifert Prof. Dr. Thomas C. Marlovits Dr. Jennifer Herrmann Prof. Dr. Rolf Müller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202214094