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91.
92.
V. V. Kovalev Yu. E. Gorbunova G. A. Razgonyaeva S. A. Kozyukhin Yu. V. Kokunov 《Russian Journal of Coordination Chemistry》2014,40(11):801-805
The complex [CdI2(4-CNPy)2] (I) was obtained by a reaction of CdI2 with 4-cyanopyridine (4-CNPy, C6H4N2) and structurally characterized (CIF file CCDC no. 983377). The crystals of complex I are monoclinic, space group C2, a = 24.698(5) Å, b = 4.127(1) Å, c = 7.597(2) Å, β = 96.05(1)°, V = 770.0(3) Å3, ρcalcd = 2.477 g/cm3, Z = 2. In structure I, iodine atoms serve to unite complex molecules into the polymer chains [CdI2(4-CNPy)2]∞ along the direction [010]. The Cd(1) atom lying on a twofold axis has a slightly distorted octahedral environment made up of four bridging iodine atoms and two nitrogen atoms of two ligands 4-CNPy (Cd-Iav, 2.947(2) and Cd-N(1), 2.410(6) Å). Within each chain, cadmium atoms are spaced apart at 4.13 Å. Complex I exhibits photoluminescence. 相似文献
93.
Transalkylation of Higher Trifluoromethylated Fullerenes with C70: A Pathway to New Addition Patterns of C70(CF3)8 下载免费PDF全文
Nikita M. Belov Marina G. Apenova Alexey V. Rybalchenko Eugenia V. Borkovskaya Dr. Natalia S. Lukonina Dr. Alexey A. Goryunkov Dr. Ilya N. Ioffe Prof. Dr. Sergey I. Troyanov Prof. Dr. Lev N. Sidorov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):1126-1133
We report three new isomers of C70(CF3)8, structurally related to p7mp‐C70(CF3)10, that are inaccessible by direct trifluoromethylation, but can be easily identified among the products of the transalkylation of higher trifluoromethylfullerenes with C70. The reported compounds are characterized by UV/Vis, 1 D and 2 D COSY 19F NMR spectroscopy, and DFT calculations. A rather unusual addition pattern is observed in p6,i‐C70(CF3)8 in which one addend is attached remotely from the others; polarization of the adjacent unsaturated bonds by the addend makes the molecule readily oxidizable. 相似文献
94.
Weina Li Sergey Fedosov Tianwei Tan Xuebing Xu Zheng Guo 《Applied biochemistry and biotechnology》2014,173(1):278-290
To maintain biological functions, thousands of different reactions take place in human body at physiological pH (7.0) and mild conditions, which is associated with health and disease. Therefore, to examine the catalytic function of the intrinsically occurring molecules, such as amino acids at neutral pH, is of fundamental interests. Natural basic α-amino acid of l-lysine, l-arginine, and l-histidine neutralized to physiological pH as salts were investigated for their ability to catalyze Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate. Compared with their free base forms, although neutralized alkaline amino acid salts reduced the catalytic activity markedly, they were still capable to perform an efficient catalysis at physiological pH as porcine pancreatic lipase (PPL), one of the best enzymes that catalyze Knoevenagel condensation. In agreement with the fact that the three basic amino acids were well neutralized, stronger basic amino acid Arg and Lys showed more obvious variation in NH bend peak from the FTIR spectroscopy study. Study of ethanol/water system and quantitative kinetic analysis suggested that the microenvironment in the vicinity of amino acid salts and protonability/deprotonability of the amine moiety may determine their catalytic activity and mechanism. The kinetic study of best approximation suggested that the random binding might be the most probable catalytic mechanism for the neutralized alkaline amino acid salt-catalyzed Knoevenagel condensation. 相似文献
95.
Elena V. Ukhatskaya Sergey V. Kurkov Roman V. Rodik Vitaly I. Kalchenko Susan E. Matthews Phatsawee Jansook Thorsteinn Loftsson 《Journal of inclusion phenomena and macrocyclic chemistry》2014,79(3-4):473-483
The self-aggregation ability of three amphiphilic cationic calix[4]arenes possessing four quaternary amino groups (aminoCAs) was investigated using a variety of methods. All of the studied compounds possess high aggregation ability. Their critical aggregation concentration (CAC) values in water are in the 0.0009–0.04 % (w/v) concentration range. Several size populations of aggregates were detected by DLS for all three CAs, and restructuring of aggregates was observed to be dependent on concentration. Particles formed above CAC were attributed to formation of vesicular structures (vesicles). The coexistence of other type of aggregates (presumably micelles) with vesicles was observed in the aqueous solution of CAs 2 and 3 from concentrations of 0.5 and 0.8 % (w/v), respectively. The filtration procedure was found to be a significant factor since the obtained data from filtered and unfiltered samples was different. The particle sizes obtained by TEM measurements were somewhat correlated with the DLS data for unfiltered CAs solutions. An analysis of the aggregate composition was undertaken by a size-exclusion method using semi-permeable cellophane membranes with different MWCO. A negative deviation from linearity of permeability flux profile starting from 0.8 % (w/v) concentration of donor phase indicated that the fraction of large aggregates at this point is significant enough that the molecules could not easily permeate through the membranes. 相似文献
96.
Osipov Artem A. Iankevich Gleb A. Alexandrov Sergey E. 《Plasma Chemistry and Plasma Processing》2020,40(1):423-431
Plasma Chemistry and Plasma Processing - In this study, the dry plasma-chemical etching process of monocrystalline SiO2 (quartz) in a fluoride-based (sulfur hexafluoride, SF6) inductively coupled... 相似文献
97.
Belikov Mikhail Yu. Ievlev Mikhail Yu. Fedoseev Sergey V. Ershov Oleg V. 《Research on Chemical Intermediates》2020,46(7):3477-3490
Research on Chemical Intermediates - A series of negative T-type nitrile-rich photochromes containing a hydroxytricyanopyrrole acceptor was synthesized. It was shown that thermal stability of the... 相似文献
98.
Hideyuki Tatsuno Kasper S. Kjr Kristjan Kunnus Tobias C. B. Harlang Cornelia Timm Meiyuan Guo Pavel Chbera Lisa A. Fredin Robert W. Hartsock Marco E. Reinhard Sergey Koroidov Lin Li Amy A. Cordones Olga Gordivska Om Prakash Yizhu Liu Mads G. Laursen Elisa Biasin Frederik B. Hansen Peter Vester Morten Christensen Kristoffer Haldrup Zoltn Nmeth Dorottya Srosin Szemes va Bajnczi Gyrgy Vank Tim B. Van Driel Roberto Alonso‐Mori James M. Glownia Silke Nelson Marcin Sikorski Henrik T. Lemke Dimosthenis Sokaras Sophie E. Canton Asmus O. Dohn Klaus B. Mller Martin M. Nielsen Kelly J. Gaffney Kenneth Wrnmark Villy Sundstrm Petter Persson Jens Uhlig 《Angewandte Chemie (International ed. in English)》2020,59(1):364-372
Iron N‐heterocyclic carbene (NHC) complexes have received a great deal of attention recently because of their growing potential as light sensitizers or photocatalysts. We present a sub‐ps X‐ray spectroscopy study of an FeIINHC complex that identifies and quantifies the states involved in the deactivation cascade after light absorption. Excited molecules relax back to the ground state along two pathways: After population of a hot 3MLCT state, from the initially excited 1MLCT state, 30 % of the molecules undergo ultrafast (150 fs) relaxation to the 3MC state, in competition with vibrational relaxation and cooling to the relaxed 3MLCT state. The relaxed 3MLCT state then decays much more slowly (7.6 ps) to the 3MC state. The 3MC state is rapidly (2.2 ps) deactivated to the ground state. The 5MC state is not involved in the deactivation pathway. The ultrafast partial deactivation of the 3MLCT state constitutes a loss channel from the point of view of photochemical efficiency and highlights the necessity to screen transition‐metal complexes for similar ultrafast decays to optimize photochemical performance. 相似文献
99.
100.
Sergey Vyazovkin 《国际化学动力学杂志》1996,28(2):95-101
Basic problems of kinetic processing of nonisothermal data ascertained from thermal analysis measurements can be solved by isoconversional methods. Analysis of the dependence of the activation energy on conversion often permits the identification of the kinetic scheme for the process. This dependence may also be used to solve applied kinetic problems related to predicting the behavior of a substance outside the range of experimental temperatures. Methods for using this dependence for evaluating both the preexponential factor and the reaction model, as well as for detecting isokinetic relationships, have been discussed. Because all of these operations have a common origin in computing the dependence of the activation energy on conversion, isoconversional methods may be considered as a basis of a unified approach to kinetic processing of nonisothermal data. © 1996 John Wiley & Sons, Inc. 相似文献