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991.
992.
William E. AcreeJr. Abolghasem Jouyban Fleming Martinez 《Journal of solution chemistry》2017,46(3):734-737
Mathematical representations reported by Yu et al. for the CNIBS/R–K model and a hybrid model are carefully examined in regards to the model’s ability to predict the solubility of hexaquocobalt(II) bis(p-toluenesulfonate). The equation coefficients reported by Yu et al. were found to give calculated mole fraction solubilities in ethanol that exceed unity for both models. 相似文献
993.
William A. Alexander 《Journal of mathematical chemistry》2017,55(2):423-435
A statistical mechanical model that treats hydrocarbon self-assembled monolayer (SAM) chains as rigid rods is examined to interrogate the mechanisms involved in monolayer ordering. The statistical mechanical predictions are compared to fully atomistic molecular dynamics simulations of SAMs with different packing densities. The monolayer chain order is examined as a function of surface coverage, chain-surface interactions, and chain–chain interactions. Reasonable interaction potentials are deduced from ab initio electronic structure calculations of small model systems. It is found that the chain-surface interaction is the most important parameter in formation of flat-lying monolayer phases, while formation of standing phase monolayers is driven most importantly by increased density of molecules at the surface. A brief discussion of the utility and validity of the rigid rod treatment is given in light of the molecular dynamics results. 相似文献
994.
A novel class of nematic liquid crystalline organic semiconducting oligomers incorporating N-heterocyclic carbazole moieties has been synthesised using simple and highly efficient reaction pathways. The electroluminescent colour of these novel oligomers can be varied in a controlled manner by molecular design. The values of the ionisation potential and the electron affinity of these electroluminescent oligomers can also be matched by structural design to the Highest Occupied Molecular Orbital (HOMO) energy level of the electron-blocking layer and the Lowest Unoccupied Molecular Orbital (LUMO) energy level of electron-transporting layer in the Organic light emitting diodes to create low charge-injection barriers for electrons and holes, respectively leading to electroluminescence with an efficacy up to 4.1 cd A?1. 相似文献
995.
996.
Wang Y Dai Q Zou B Yu WW Liu B Zou G 《Langmuir : the ACS journal of surfaces and colloids》2010,26(24):19129-19135
In comparison to the previous lengthy approaches, we described a general and simple strategy for engineering the superlattice assembly of IV-VI semiconductor nanocrystals (NCs) with tunable sizes and morphologies. Not only the well-studied spherical NCs but also some special-shaped NCs, such as the quasi-cubic, cubic, truncated octahedral, and octahedral, could self-assemble into well-ordered patterns, as demonstrated in PbS, PbSe, and PbTe. These results extended our proposed model about the configuration of ligand chains in the superlattice assembly. This powerful capability of assembling superlattices was dominated by a heat-treatment process, providing a significant and extensive direction in the engineering of morphology-tunable NC superlattices. 相似文献
997.
William J. Evans Prof. Thomas J. Mueller Joseph W. Ziller Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):964-975
The limits of steric crowding in organometallic metallocene complexes have been examined by studying the synthesis of [(C5Me5)3MLn] complexes as a function of metal in which L=Me3CCN, Me3CNC, and Me3SiCN. The bis(tert‐butyl nitrile) complexes [(C5Me5)3Ln(NCCMe3)2] (Ln=La, 1 ; Ce, 2 ; Pr, 3 ) can be isolated with the largest lanthanide metal ions, La3+, Ce3+, and Pr3+. The Pr3+ ion also forms an isolable mono‐nitrile complex, [(C5Me5)3Pr(NCCMe3)] ( 4 ), whereas for Nd3+ only the mono‐adduct [(C5Me5)3Nd(NCCMe3)] ( 5 ) was observed. With smaller metal ions, Sm3+ and Y3+, insertion of Me3CCN into the M? C(C5Me5) bond was observed to form the cyclopentadiene‐substituted ketimide complexes [(C5Me5)2Ln{NC(C5Me5)(CMe3)}(NCCMe3)] (Ln=Sm, 6 ; Y, 7 ). With tert‐butyl isocyanide ligands, a bis‐isocyanide product can be isolated with lanthanum, [(C5Me5)3La(CNCMe3)2] ( 8 ), and a mono‐isocyanide product with neodymium, [(C5Me5)3Nd(CNCMe3)] ( 9 ). Silicon–carbon bond cleavage was observed in reactions between [(C5Me5)3Ln] complexes and trimethylsilyl cyanide, Me3SiCN, to produce the trimeric cyanide complexes [{(C5Me5)2Ln(μ‐CN)(NCSiMe3)}3] (Ln=La, 10 ; Pr, 11 ). With uranium, a mono‐nitrile reaction product, [(C5Me5)3U(NCCMe3)] ( 12 ), which is analogous to 5 , was obtained from the reaction between [(C5Me5)3U] and Me3CCN, but [(C5Me5)3U] reacts with Me3CNC through C? N bond cleavage to form a trimeric cyanide complex, [{(C5Me5)2U(μ‐CN)(CNCMe3)}3] ( 13 ). 相似文献
998.
The application of L-Selectride, either alone or in combination with ZnCl2, to aryl ketones 1, 8 and 11 resulted in highly anti-stereoselective reduction. In contrast, lactols 22 and 23 gave a moderate syn-preference using L-Selectride alone and a high syn-preference in the presence of ZnCl2. Uniquely, high anti- stereoselectivity was observed in the reduction of o-anisyl lactol 37 with L-Selectride alone, which was switched to a high syn-preference when ZnCl2 was present. 相似文献
999.
The new ligand cis,cis-1,3,5-tris-(E)-(tolylideneimino)cyclohexane (TACH-o-tolyl) forms a 1:1 complex with iron(II). Addition of substituted phenolates forms 1:1:1 ligand:iron:phenolate complexes, which have been characterized both in the solid state and in solution. There is complete binding of the phenolate to the complex only when there are ortho-halogens on the phenolate. The tertiary complexes with ortho-halo-substituted phenolates exhibit short Fe-halogen distances, and the complex containing a non-coordinating but similarly sized ortho-methyl phenolate has a significantly different conformation and coordination geometry. Therefore, it is likely that the metal-halogen interaction stabilizes the complexes. The iron(II)-halogen interaction in these complexes may explain the substrate specificity of PcpA and LinE, enzymes that preferentially bind phenols and hydroquinones containing halogen substituents in ortho positions. 相似文献
1000.
An unusually high yielding fluorination of aminopyralid (3) using F-TEDA (SELECTFLUOR™) in warm water, followed by kinetic resolution (via iterative esterification/saponification) of the crude fluorination product with dry HCl in methanol produced pure ring-fluorinated pyridine 2 in an overall yield of 31% for the two steps. 相似文献