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991.
Abstract New N-substituted 4-arylidene-isoquinoline-1,3-dione derivatives were obtained as one geometrical isomer by aldol condensation of the appropriate aldehyde and the corresponding N-substituted homophthalimides. The structural elucidation of compounds 3a–h was established by infrared and NMR spectroscopy including 1 H, 13 C, CH CORR, and distortionless enhancement by polarization transfer measurements. Compounds 3d–h were evaluated for their antibacterial activity against some strains of bacteria using the disc diffusion method and microdilution tests. 相似文献
992.
A series of self-healable polyurethane (SHPU)/modified graphene (MG) nanocomposites were synthesized from poly(tetramethylene glycol) (PTMG) and 4,4′-methylene diphenyl diisocyanate (MDI) with minute amounts (0–1 wt%) of MG which was chemically modified graphene oxide (GO) with phenyl isocyanate and reduced in the presence of phenylhydrazine. 相似文献
993.
Makoto Hatakeyama Takako Mashiko Hisanao Hazama Kunio Awazu Masanori Tachikawa 《International journal of quantum chemistry》2013,113(2):125-129
To investigate the correlation between the wavelength dependence of ionization threshold fluence of target molecule in matrix‐assisted laser desorption/ionization by infrared (IR) laser and the IR absorption spectrum of matrix molecule, we have analyzed the IR absorption spectra of four matrix molecules using density functional theory and correlated ab initio molecular orbital method. The calculated IR absorption spectra of the isolated molecules showed more qualitative correlation with the wavelength dependence of ionization threshold fluence than those of the solid state structures. We can consider that a portion of matrix molecules lost the ordered crystal structure and that the transition to the diluted or isolated state occurred at the early process of IR laser irradiation. © 2012 Wiley Periodicals, Inc. 相似文献
994.
Hamid Berriche 《International journal of quantum chemistry》2013,113(9):1349-1357
The potential energy curves and spectroscopic constants of the ground and many excited states of the FrAr van der Waals system have been determined using a one‐electron pseudopotential approach. The Fr+ core and the electron–Ar interactions are replaced by effective potentials. The Fr+Ar core–core interaction is incorporated using the accurate CCSD(T) potential of Hickling et al. (Phys. Chem. Chem. Phys. 2004, 6, 4233). This approach reduces the number of active electrons of the FrAr van der Waals system to only one valence electron, which permits the use of very large basis sets for the Fr and Ar atoms. Using this technique, the potential energy curves of the ground and many excited states are calculated at the self consistent field (SCF) level. In addition, the spin–orbit interaction is also considered using the semiempirical scheme for the states dissociating into Fr (7p) and Fr (8p). The FrAr system is not studied previously and its potential interactions, spectroscopic constants and dipole functions are presented here for the first time. Furthermore, we have predicted the X2Σ+–A2Π1/2, X2Σ+–AΠ3/2, X2Σ+–B2Σ1/2+, X2Σ+–32Π1/2, X2Σ+–32Π3/2, and X2Σ+–52Σ1/2+ absorption spectra. © 2012 Wiley Periodicals, Inc. 相似文献
995.
Five new 2,2′-bipyridines functionalized with a perylene or a perylenediimide moiety were synthesized and the corresponding heteroleptic ruthenium(II) complexes ([Ru(bpy)2(L)](PF6)2; bpy = 2,2′-bipyridyl, L = perylene-substituted bpy ligand) were prepared. The UV–vis spectra of the ruthenium(II) complexes showed red-shifted and intense absorption bands derived from the conjugated structure of the new ligands. 相似文献
996.
Two dinuclear succinato‐bridged nickel(II) complexes [Ni(RR‐L)]2(μ‐SA)(ClO4)2 ( 1 ) and [Ni(SS‐L)]2(μ‐SA)(ClO4)2 ( 2 ) (L = 5, 5, 7, 12, 12, 14‐hexamethyl‐1, 4, 8, 11‐tetraazacyclotetradecane, SA = succinic acid) were synthesized and characterized by EA, Circular dichroism (CD), as well as IR and UV/Vis spectroscopy. Single crystal X‐ray diffraction analyses revealed that the NiII atoms display a distorted octahedral coordination arrangement, and the succinato ligand bridges two central NiII atoms in a bis bidentate fashion to form dimers in 1 and 2 . The monomers of {[Ni(RR‐L)]2(μ‐SA)}2+ and {[Ni(SS‐L)]2(μ‐SA)}2+ are connected by O–H ··· O and N–H ··· O hydrogen bonds into a 1D right‐handed and left‐handed helical chain along the b axis, respectively. The homochiral natures of 1 and 2 are confirmed by the results of CD spectroscopy. 相似文献
997.
Kalipada Adhikari Sudip Chattopadhyay Barin Kumar De Amitava Sharma Ranendu Kumar Nath Dhiman Sinha 《Journal of computational chemistry》2013,34(15):1291-1310
A valence‐universal multireference coupled cluster (VUMRCC) theory, realized via the eigenvalue independent partitioning (EIP) route, has been implemented with full inclusion of triples excitations for computing and analyzing the entire main and several satellite peaks in the ionization potential spectra of several molecules. The EIP‐VUMRCC method, unlike the traditional VUMRCC theory, allows divergence‐free homing‐in to satellite roots which would otherwise have been plagued by intruders, and is thus numerically more robust to obtain more efficient and dependable computational schemes allowing more extensive use of the approach. The computed ionization potentials (IPs) as a result of truncation of the (N−1) electron basis manifold involving virtual functions such as 2h‐p and 3h‐2p by different energy thresholds varying from 5 to 15 a.u. with 1 a.u. intervals as well as thresholds such as 20, 25, and 30 a.u. have been carefully looked into. Cutoff at around 25 a.u. turns out to be an optimal threshold. Molecules such as C2H4 and C2H2 (X = D,T), and N2 and CO (X = D,T,Q) with Dunning's cc‐pVXZ bases have been investigated to determine all main and 2h‐p shake‐up and 3h‐2p double shake‐up satellite IPs. We believe that the present work will pave the way to a wider application of the method by providing main and satellite IPs for some problematic N‐electron closed shell systems. © 2013 Wiley Periodicals, Inc. 相似文献
998.
《Journal of Dispersion Science and Technology》2013,34(3-4):557-567
Abstract In the present work, microstructure and superparamagnetic properties of two types of carbon‐coated magnetic Ni and Fe nanoparticles [Ni(C) and Fe(C)] are reviewed. High‐resolution transmission electron microscopy (HRTEM), electron diffraction (SAED), and x‐ray diffraction (XRD) analyses have been used to reveal the distinct structural morphologies of Ni and Fe nanoparticles. Moreover, novel carbon‐coated Ni nanoparticle assemblies offer us great opportunities for studying the mechanism of superparamagnetism in particle assemblies. Magnetization measurements [M(T) and M(H) curves] for assemblies of Ni nanoparticles indicate that modified superparamagnetic properties at T > T B, have been found in the assemblies of Ni(C) particles. The blocking temperature, T B, is determined to be near 115K under a certain applied field. Above T B, the magnetization M(H, T) can be described by the classical Langevin function L using the relation, M/M s (T = 0) = coth (μH/kT) ? kT/μH. It is suggested that these assemblies of carbon‐coated Ni nanoparticles have typical single‐domain, field‐dependent superparamagnetic relaxation properties. Finally, Mössbauer spectra and hyperfine magnetic fields at room temperature for the assemblies of Fe(C) nanoparticles confirm their distinct nanophases that were detected by structural analysis. Modified superparamagnetic relaxation is observed in the assemblies of Fe(C) nanoparticles, which is attributed to the nanocrystalline nature of the carbon‐coated nanoparticles. 相似文献
999.
Feng Yan Xian‐Guang Wang Zhen‐Quan Li Lu Zhang Jia‐Yong Yu 《Journal of Dispersion Science and Technology》2013,34(3):387-396
A series of anionic N‐acyltaurate surfactants, side chain containing aromatic nucleus (abbreviated as SAATT), were synthesized via Williamson reaction, hydrolyzation, and acylation. Krafft temperatures and surface properties of these surfactants at 30°C, that is, critical micelle concentration, cmc, surface excess concentration, Γmax, surface area demand per molecule, A min, efficiency in surface tension reduction, pC20, effectiveness in surface tension reduction, πcmc, and cmc/C20 parameter were determined. It was shown that these surfactants exhibit good solubility which was confirmed by measuring Krafft temperature. The cmc of SAATT was much smaller than that of conventional surfactants with similar effective carbon numbers, and shifted to lower concentration with increasing hydrocarbon chain length. In addition, the γcmc decreased with decrease in Γmax. The pC20 and the cmc/C20 got larger with the increase in hydrocarbon chain length. From the fluorescence intensity ratios of I 1 (373 nm) and I 3 (384 nm) using pyrene as a probe, it was indicated that the molecules of SAATT formed loose micelles with a broad size distribution. 相似文献
1000.
利用X射线衍射、N2吸附等温线、X射线光电子能谱、X射线吸收谱、H2-程序升温还原、甲基橙选择化学吸附和等电点测定等方法研究了共沉淀方法制备的一系列CexTi1-xO2复合氧化物的结构. 成功发展了甲基橙选择化学吸附和等电点方法研究CexTi1-xO2复合氧化物的最外层表面结构, 并定义了“等价CeO2表面覆盖度”来描述CexTi1-xO2复合氧化物的最外层表面结构. CexTi1-xO2复合氧化物 (x ≥ 0.7)形成立方萤石相固溶体, Ce0.3Ti0.7O2表现出纯的单斜相, 而其它复合氧化物表现出混合相. CexTi1-xO2复合氧化物最外层表面结构的演变行为不同于其体相结构.Ce0.7Ti0.3O2立方萤石相固溶体最外层表面已经部分形成了单斜相Ce0.3Ti0.7O2, 随Ce含量的降低, 单斜相Ce0.3Ti0.7O2从最外层表面向体相生长. CexTi1-xO2复合氧化物立方萤石相固溶体和单斜相Ce0.3Ti0.7O2分别在相对较低和较高的温度表现出好的还原性能. 上述结果提供了全面和深层次的CexTi1-xO2复合氧化物结构信息. 相似文献