Cu(DMBC)2(H2O)2(DMBC:3,5-二甲基苯氧基乙酸)配合物层状超分子的水热合成、结构及生物活性

用聚乙二醇400为相转移催化剂,由3,5-二甲基苯酚和氯乙酸合成了3,5-二甲基苯氧基乙酸(DMBC),用水热法将它与氯化铜合成了配合物Cu(DMBC)2(H2O)2,通过元素分析、红外光谱对其进行了表征;采用X射线单晶衍射法测定了其晶体和分子结构。其晶体属单斜晶系,P21/c空间群。晶胞参数:a=1.526(2)nm,b=0.7092(11)nm,c=1.0942(17)nm,β=104.567(15)°,V=1.146(3)nm3,Z=2,F(000)=478。在分子中,Cu(Ⅱ)分别与2个配体的羧基氧原子和2个水分子配位,中心离子构成稍微变形的平面四边形配位构型。分之间通过氢键和π-π相互作用自组装成稳定的二维层状超分子。利用Gauss03程序,在B3LYP/6-31G水平上对标题化合物进行了量化计算,给出了配合物分子中各原子的净电荷布居,计算结果与测定结果吻合。测试了该配合物对油菜籽发芽生长促进活性和抑菌作用。CCDC:909139     

BrФnsted Acidic Ionic Liquids as Efficient Catalysts and Mediums for the Synthesis of Half-esters: Structure-catalytic Selectivity Relationship

BrФnsted acidic ionic liquids based on imidazolium cation were employed as efficient catalysts and mediums for the ring opening of phthalic anhydride to synthesize half-esters. Good yields, short reaction time and mild reaction condition were achieved. Lower acidity of ionic liquid resulted in higher catalytic selectivity in the synthesis of half-esters. The minimum-energy geometries of sulfonic acid-functionalized ionic liquids based on imidazolium cation revealed that their acidities and catalytic selectivity in the synthesis of half-esters were related to their structures.     

A New Semi-conductive Copper(I) Halide Coordination Polymer: Synthesis, Structure, and Theoretical Study

Abstract  A 1-D hybrid copper(I) halides, [(phen)Cu₃I₃] _n (phen = 1,10-phenanthroline)(1) with novel D6R (double six-membered rings) Cu₆I₆ cores, was synthesized by solvothermal reaction and characterized by single-crystal X-ray diffraction. In 1, nitrogen atoms from phen replace two I of CuI₄ tetrahedron to give distorted tetrahedral geometries (CuI₂N₂), then CuI₂N₂ tetrahedron shares corners via μ₃-I to generate an extended 1-D zigzag chain. Two zigzag chains combines with one 1-D (Cu₄I₄) _n chain containing D6R cores via μ₃-I-Cu (from cores) bonds to form the infinite 1-D ribbonlike polymer along the a-axis. Furthermore, the title compound is stabilized by conspicuous C–H···I hydrogen bonds, π–π and d¹⁰–d¹⁰ metallic interactions. Experimental and theoretical optical property investigation indicates that 1 possesses semiconductor property. DFT calculation was executed to probe the electronic structure of 1. To our interest, phen act as a property control species with its π* electrons appear in the forbidden band. Graphical Abstract  A hybrid copper(I) halides [(phen)Cu₃I₃] _n containing D6R cores was structurally determined, which was stabilized by conspicuous C–H···I hydrogen bonds, π–π and d¹⁰–d¹⁰ metallic interactions and possesses semiconductor property. DFT calculation indicate phen act as a property control species with its π* electrons appear in the forbidden band. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Electrosyntheses and characterization of poly(9-bromophenanthrene) in boron trifluoride diethyl etherate

A novel semi-conducting polymer poly(9-bromophenanthrene) (P9BP) was synthesized electrochemically by direct anodic oxidation of it is monomer 9-bromophenanthrene (9BP) in boron trifluoride diethyl etherate (BFEE). The oxidation onset potential of 9BP in this medium was measured to be only 1.33 V vs. saturated calomel electrode (SCE). P9BP films obtained from BFEE showed good electrochemical behavior and nice thermal stability with electrical conductivity of 0.03 S cm⁻¹. FTIR and ¹H NMR spectra together with theoretical quantum chemistry calculations indicated that the P9BP was mainly grown via the coupling of the monomer at C₃ and C₆ positions. Furthermore, P9BP exhibited strong electrochromic nature from opaque green to light yellow between the doped and dedoped states on ITO electrode in solid state. Fluorescence spectral studies indicated that P9BP was a blue light emitter.     

Theoretical electronic structure of the molecule ScI

Theoretical investigation of the 18 lowest electronic states of the molecule ScI in the representation ^2S+1Λ^(±) has been performed via CASSCF and MRCI (single and double excitation with Davidson correction) calculations. To the best of our knowledge these calculated electronic states are the first ones from ab initio methods. Thirteen electronic states between 4,500 cm^?1 and 21,000 cm^?1 have been studied for the first time and have not yet been observed experimentally. The harmonic frequency ω_e, the internuclear distance R_e, the electronic transition energy with respect to the ground state T_e, and the rotational constant B_e have been calculated for the considered electronic states. By using the canonical functions approach the eigenvalues E_υ and the rotational constants B_υ have also been calculated for the six lowest‐lying electronic states. The comparison of these results with the theoretical and the experimental data available in the literature shows a good agreement. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Investigation on stabilities and spectroscopy of C80O2 based on C80 (D5d) using density functional theory

The relative stabilities of the 17 possible isomers for C₈₀O₂ based on C₈₀ (D_5d) were studied using Becke three parameters plus Lee, Yang, and Parr's (B3LYP) method and 6‐31G (d) basis set in density functional theory. The most stable geometry of C₈₀O₂ was predicted to be 23,24,27,28‐C₈₀O₂ (A) with annulene‐like structures, where the additive bonds are those between two hexagons (6/6 bonds) near the equatorial belt of C₈₀ (D_5d). Electronic spectra of C₈₀O₂ isomers were calculated based on the optimized geometries using intermediate neglect of differential overlap (INDO) calculation. Compared with those of C₈₀ (D_5d), the first absorptions in the electronic spectra of C₈₀O₂ are blue‐shifted owing to the wide energy gaps. ¹³C nuclear magnetic resonance spectra and nucleus independent chemical shifts of the C₈₀O₂ isomers were computed at B3LYP/6‐31G level. The chemical shifts of the bridged carbon atoms in the epoxy structures of C₈₀O₂ compared with those of the bridged carbon atoms in the annulene‐like structures are changed upfield. Generally, the isomers with the annulene‐like structures of C₈₀O₂ are more aromatic than those with the epoxy structures. The addition of the oxygen atoms near the pole of C₈₀ (D_5d) is favorable to improving the aromaticities of C₈₀O₂. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Fragmentation of deprotonated cyclic dipeptides by electrospray ionization mass spectrometry

The fragmentation pathways of deprotonated cyclic dipeptides have been studied by electrospray ionization multi‐stage mass spectrometry (ESI‐MSⁿ) in negative mode. The results showed that the fragmentation pathways of deprotonated cyclic dipeptides depended significantly on the different substituents, the side chains of amino acid residues at the diketopiperazine ring. In the spectra of deprotonated cyclic dipeptides, the ion [M? H? substituent radical]^? was firstly observed in the ESI mode. The characteristic fragment ions [M? H? substituent radical]^? and [M? H? (substituent? H)]^? could be used as the symbols of particular cyclic dipeptides. The hydrogen/deuterium (H/D) exchange experiment, the high‐resolution mass spectrometry (Q‐TOF) and theoretical calculations were used to rationalize the proposed fragmentation pathways and to verify the differences between the fragmentation pathways. The relative Gibbs free energies (ΔG) of the product ions and possible fragmentation pathways were estimated using the B3LYP/6–31++G(d, p) model. The results have some potential applications in the structural elucidation and interpretation of the mass spectra of homologous compounds and will enrich the gas‐phase ESI‐MS ion chemistry of cyclic dipeptides. Copyright © 2009 John Wiley & Sons, Ltd.     

In silico prediction of drug solubility: 4. Will simple potentials suffice?

In view of the extreme importance of reliable computational prediction of aqueous drug solubility, we have established a Monte Carlo simulation procedure which appears, in principle, to yield reliable solubilities even for complex drug molecules. A theory based on judicious application of linear response and mean field approximations has been found to reproduce the computationally demanding free energy determinations by simulation while at the same time offering mechanistic insight. The focus here is on the suitability of the model of both drug and solvent, i.e., the force fields. The optimized potentials for liquid simulations all atom (OPLS‐AA) force field, either intact or combined with partial charges determined either by semiempirical AM1/CM1A calculations or taken from the condensed‐phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field has been used. The results illustrate the crucial role of the force field in determining drug solubilities. The errors in interaction energies obtained by the simple force fields tested here are still found to be too large for our purpose but if a component of this error is systematic and readily removed by empirical adjustment the results are significantly improved. In fact, consistent use of the OPLS‐AA Lennard‐Jones force field parameters with partial charges from the COMPASS force field will in this way produce good predictions of amorphous drug solubility within 1 day on a standard desktop PC. This is shown here by the results of extensive new simulations for a total of 47 drug molecules which were also improved by increasing the water box in the hydration simulations from 500 to 2000 water molecules. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009     

磷的四原子簇合物的从头算研究

在ＳＴＯ－３Ｇ、３－２１Ｇ、３－２１Ｇ、４－３１Ｇ和４－３１Ｇ基组水平上，对磷的四原子簇合物Ｐ４＾２＋，Ｐ４，Ｐ４＾２－，Ｐ４＾４－做了ＳＣＦ－ＭＯ从头算研究。几何优化表明，对于已知结构的族合物分子计算结果与实验测定了几何形一致，同时确定了实验上结构未知的簇合物分子的稳定２几何。根据计算结果对四原子磷簇合物系列分子的相对稳定性和几何形了讨论。     

双桥反应机理的从头计算研究

有大量文献[1-3]对有机化学反应中的反式加成、邻基参与下的反式消去反应所涉及的三元环过程（我们称之为单桥反应机理）进行了研究·负离子以相等的几率进攻成桥的二个碳原子中的任意一个，因而对大量反应的立体选择性给出了很好的解释．但是有些反应却不能用这一机理解释．FinarN］指出其原因还不清楚，并推测这是由于桥键可以断裂而形成开环经典离子，使原来的桥原子所跨碳碳单键旋转．这儿相当于给出了两种并存的机理．HoPkhson等人＊以乙烯和氟或氯加成为模型，对单桥机理进行了量子化学从头算研究·得到这两个反应的活化能分别大于5…