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We have developed a liquid-phase synthesis of combinatorial libraries of new disubstituted 4-oxo-2-thioxo-1,2,3,4-tetrahydroquinazolines and trisubstituted 4-oxo-3,4-dihydroquinazoline-2-thioles. The former were prepared using two general procedures: (i) cyclization of substituted methyl anthranilates with isothiocyanates, or (ii) cyclization of substituted 2-(methylcarboxy)benzeneisothiocyanates with primary amines or hydrazines. 4-Oxo-3,4-dihydroquinazoline-2-thioles were prepared by S-alkylation of disubstituted 4-oxo-2-thioxo-1,2,3,4-tetrahydroquinazolines with alkyl or aryl halides. The hydrolysis of methyl benzimidazo[1,2-c]quinazoline-6(5H)-thione-3-carboxylate led to the corresponding acid. This acid was utilized in the synthesis of new benzimidazo[1,2-c]quinazoline-6(5H)-thione-3-carboxamide and S-substituted 6-mecaptobenzimidazo[1,2-c]quinazoline-3-carboxamide libraries. 相似文献
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Squeezing,Then Stacking: From Breathing Pores to Three‐Dimensional Ionic Self‐Assembly under Electrochemical Control 下载免费PDF全文
Kang Cui Dr. Kunal S. Mali Dr. Oleksandr Ivasenko Dongqing Wu Dr. Xinliang Feng Dr. Michael Walter Prof. Klaus Müllen Prof. Steven De Feyter Dr. Stijn F. L. Mertens 《Angewandte Chemie (International ed. in English)》2014,53(47):12951-12954
We demonstrate the spontaneous and reversible transition between the two‐ and three‐dimensional self‐assembly of a supramolecular system at the solid–liquid interface under electrochemical conditions, using in situ scanning tunneling microscopy. By tuning the interfacial potential, we can selectively organize our target molecules in an open porous pattern, fill these pores to form an auto‐host–guest structure, or stack the building blocks in a stratified bilayer. Using a simple electrostatic model, we rationalize which charge density is required to enable bilayer formation, and conversely, which molecular size/charge ratio is necessary in the design of new building blocks. Our results may lead to a new class of electrochemically controlled dynamic host–guest systems, artificial receptors, and smart materials. 相似文献
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Dr. Oleksandr Kysliak Dr. Claudio Schrenk Prof. Dr. Andreas Schnepf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18787-18793
Recently the metalloid cluster compound [Ge9Hyp3]? ( 1 ; Hyp=Si(SiMe3)3) was oxidatively coupled by an iron(II) salt to give the largest metalloid Group 14 cluster [Ge18Hyp6]. Such redox chemistry is also possible with different transition metal (TM) salts TM2+ (TM=Fe, Co, Ni) to give the TM+ complexes [Fe(dppe)2][Ge9Hyp3] ( 3 ; dppe=1,2‐bis(diphenylphosphino)ethane), [Co(dppe)2][Ge9Hyp3] ( 4 ), [Ni(dppe)(Ge9Hyp3)] ( 5 ) and [Ni(dppe)2(Ge9Hyp3)]+ ( 6 ). Such a redox reaction does not proceed for Mn, for which a salt metathesis gives the first open shell [Hyp3Ge9‐M‐Ge9Hyp3] cluster ( 2 ; M=Mn). The bonding of the transition metal atom to 1 is also possible for Ni (e.g., compound 6 ), in which one or even two nickel atoms can bind to 1 . In contrast to this in case of the Fe and Co compounds 3 and 4 , respectively, the transition‐metal atom is not bound to the Ge9 core of 1 . The synthesis and the experimentally determined structures of 2 – 6 are presented. Additionally the bonding within 2 – 6 is analyzed and discussed with the aid of EPR measurements and quantum chemical calculations. 相似文献
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Dyachenko Alla Ischenko Olena Diyuk Vitaliy Goncharuk Olena Borysenko Mykola Mischanchuk Oleksandr Zakharova Tetiana Pryhunova Olha Sternik Dariush Lisnyak Vladyslav 《Research on Chemical Intermediates》2022,48(6):2607-2625
Research on Chemical Intermediates - Oxide Ni(80)Fe(20)/SiO2, Co(93)Fe(7)/SiO2, and Ni(19)Co(77)Fe(4)/SiO2 nanocomposites (NCs) were prepared using highly dispersed silica. It was modified by... 相似文献
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Oleksandr Trotsenko Yuri Roiter Sergiy Minko 《Journal of polymer science. Part A, Polymer chemistry》2010,48(14):1623-1627
In this article, we compare structures of protonated poly(2-vinylpyridine) globules (2D compact coils on the surface) adsorbed on the mica surface from aqueous solution when the shrinking is brought about either by discharging the molecules at an elevated pH or by adding monovalent and polyvalent salts. We study the structure of the PE coils using in situ atomic force microscopy experiments in aqueous solutions in a liquid cell. The abrupt coil-to-globule transition caused by pH changes and the discharge of polymer chains resulted in compact globules. If the pH corresponding to extended coil conformation remains unchanged, the coil shrinks due to the added salt. The size of the globule in the latter case corresponds to the unperturbed dimension of the polymer coil. There is no essential difference in the dimensions of the globules as obtained in the presence of monovalent and multivalent counterions for the studied ionic strength. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1623–1627, 2010 相似文献