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141.
Ananda S. Hodage Prasad P. Phadnis Amey Wadawale 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):700-710
Abstract A series of α-substituted selenenyl acetophenone derivatives of the types, [PhC(OCH2CH2O)CH2Se]2, [PhC(OCH2CH2O)CH2SeR], (PhCOCH2Se)2, and [PhCOCH2SeR] have been prepared. These compounds have been characterized by elemental analyses, IR and NMR (1H, 13C, 77Se) spectroscopy. The compounds, [PhC(OCH2CH2)CH2Se]2 and (PhCOCH2Se)2 have been structurally characterized by single crystal X-ray diffraction analyses. The former shows intra-molecular Se‐?‐?‐O interaction, while the latter exhibits inter-molecular nonbonding Se‐?‐?‐O interaction. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.] 相似文献
142.
H. R. Manjunath S. Naveen C. S. Ananda Kumar S. B. Benaka Prasad M. V. Deepa Naveen M. A. Sridhar J. Shashidhara Prasad K. S. Rangappa 《Journal of Structural Chemistry》2011,52(5):959-963
The title compound 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo[3.2.1] octane-3,4′-imidazolidine]-2′,5′-dione, C23H23FN3O2 is synthesized and the structure is investigated by X-ray diffraction studies. The compound crystallizes in the triclinic
crystal class in the P1 space group. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine
rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter-
and intramolecular hydrogen bonds of the type N-H...O, C-H...O, and C-H...N. The oxygen atom in the hydantoin ring simultaneously
accepts two hydrogen bonds to form a three-centered hydrogen bonding pattern. 相似文献
143.
Ab initio and DFT calculations on the HF/STO‐3G and B3LYP/6‐31G(d) level were performed on the conformational behaviour of isolated banana‐shaped molecules of 1,3‐phenylene bis[4‐(4‐n‐hexyloxyphenyliminomethyl)benzoate] systems (P‐6‐O‐PIMB). The influence of small substituents in both the central phenyl ring and the external phenyl rings on the shape, polarity and flexibility of these molecules was investigated by one‐ and two‐fold relaxed potential energy scans in a systematic way. The effect of substituents on the global polarity of banana‐shaped mesogens was analysed by the magnitude and direction of the dipole moment and its components in relation to the long axis of the molecules. Moreover, a simple model for the calculation of the bending angle was tested for banana‐shaped molecules with a central 1,3‐phenylene unit. The findings for the isolated banana‐shaped molecules are correlated with solid state X‐ray and liquid crystalline state NMR results. Banana‐shaped molecules with both hexyloxy (P‐6‐O‐PIMB) and hexyl (P‐6‐PIMB) terminal chains are included to study the effect of substituents in the external phenyl rings on the flexibility of these chains. An attempt will be made to correlate the results with experimental findings on banana‐shaped mesogens. 相似文献
144.
Three-component nickel-catalyzed couplings of enals, alkynes, and silanes have been developed as a new entry to enol silanes. The enol silane and a trisubstituted alkene are both formed with >98:2 stereoselectivity, and the reaction tolerates a broad range of functionality including aldehydes, ketones, esters, free hydroxyls, and basic secondary amines. A mechanistic pathway involving the formation of a metallacycle that possesses an eta1 nickel O-enolate motif explains the high level of stereoselection. 相似文献
145.
Electrochemical dimerization of vanillin in basic medium produced mixtures of meso/DL-hydrovanilloins, in contrary to earlier claims of the formation of meso-hydrovanilloin as the sole product. In the reinvestigation we have found that meso-percentage depends on the current density and the highest meso-percentage of 94% is achieved under 64 mA/cm2 current density, using Pb electrodes and 1.25 M aqueous NaOH as the electrolyte. Condensation of the renewable resources based monomer hydrovanilloin with formaldehyde in aqueous NaOH gives hydrovanilloin–formaldehyde polymer in 91% yield. The linear polymer is shown to contain hydrovanilloin units with methylene bridges connecting C-6 positions of the aromatic rings. 相似文献
146.
147.
In this work, the asymmetric case of the Malkus waterwheel is studied, where the water inflow to the system is biasing the system toward stable motion in one direction, like a Pelton wheel. The governing equations of this system, when expressed in Fourier space and decoupled to form a closed set, can be mapped into a four-dimensional space where they form a quasi-Lorenz system. This set of equations is analyzed in light of analogues of the Rayleigh Bernard convection and conclusions are drawn. The properties and behavior of the equations are studied and correlated to the physical model. Phase space behavior and linear stability analysis are used for this. Spectral analysis is used as a qualitative measure of chaos. Chaotic behavior is quantified through the calculation of the Lyapunov exponents and these are further correlated to the bifurcation diagrams for a conclusive analysis of the dynamical behavior of the system. 相似文献
148.
M. Kasthuraiah K. Ananda Kumar C. Suresh Reddy C. Devendranath Reddy 《Heteroatom Chemistry》2007,18(1):2-8
Diethyl α‐aminophosphonates ( 4 ) were prepared in excellent yield from three‐component reaction of aldehydes ( 1 ), amines ( 2 ), and triethylphosphite ( 3 ) under solvent‐free conditions in the presence of ceric ammonium nitrate (CAN) and were reacted with 2,2′‐dihydroxybiphenyl ( 5 ) using p‐toluene sulfonic acid monohydrate (PTSA) as a catalyst to obtain 6‐α‐aminodibenzo[d f][1,3,2]dioxaphosphepin 6‐oxides ( 6 ) in good yield. It is a first report on the cyclizations of 4 with 5 . An antimicrobial activity of numbers of 6 is evaluated. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:2–8, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20244 相似文献