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901.
902.
903.
ZHANG Xiu-Tang ZHAN Xiao-ping WU Ding-Ming ZHANG Quan-Zheng CHEN Shu-mei YU Ya-qin LU Can-Zhong 《结构化学》2002,21(6)
The new oxovanadium (Ⅴ) complex, [PyH][VO2(L)] 1 (salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L; Hpy is protonated pyridine) was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine. Similarly, another new complex, [VO(L)(OCH3)] 2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine. Crystal data for 1: C19H15N3O5BrV, Mr = 496.2, monoclinic, P21/n, a = 7.1885(3), b = 9.2718(3), c = 28.803(1) (A), ( = 96.185(1)(, Z = 4 and V = 1908.6(1) (A)3; for 2: C15H12N2O5BrV, Mr = 431.1, monoclinic, P21/n, a = 12.202(2), b = 8.045(2), c = 16.604(3)(A), ( = 101.29(3)(, Z = 4 and V = 1598.4(2)(A)3. The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid. Three of the four based donor atoms are from the tridentate "ONO" donor ligand while the fourth is one terminal oxygen atom with the V(1)–O(3) distance 1.646(4) (A) for 1 and one -OCH3 group with the V(1)-O(3) distance 1.753(3)(A) for 2. The V(1)-O(4) terminals occupy the axial sites in both cases. The complexes are also characterized by IR and 1H NMR spectroscopies. 相似文献
904.
在合成[Co(bpma)(tn)Cl]2+体系配合物的实验中,得到[Co(ptma)(amp)Cl]2+体系的一反式(ptma中仲胺上的氢相对于Cl)经式异构体(m3[ZnCl4]@0.5H2O),其中bpma=N,N′-二(2-吡啶基甲基)胺,tn=1,3丙二胺,ptma=N-(2-吡啶基甲基)丙二胺,amp=2-(氨基甲基)吡啶.此配合物异构体构型选择性形成的原因可能主要是其结构中配体间C-H…π相互作用使之更稳定的结果.利用单晶X-射线衍射法测定的晶体学参数:单斜晶系,空间群C2/c,a=1.55978(19)nm,b=1.33324(16)nm,c=2.2077(3)nm,β=94.832(3)°,V=4.5748(10)nm3,Dc=1.696g@cm-3,Z=8,F000=2360,μ(MoKa)=23.72cm-1,R=0.0475,Rw=0.1204.配合物离子中Co3+为六配位.晶胞中含8个配合物阳离子,8个[ZnCl4]2-阴离子及4个水分子,对映体的比例为1:1. 相似文献
905.
906.
含八齿苦味酸根的超分子苦味酸钾的合成和结构 总被引:1,自引:0,他引:1
A supramolecular complex, [Kpic]n (pic- is picratol, (NO2)3C6H2O-), has been synthesized unexpectedly in acetone solution, and characterized by elemental analysis, IR and X-ray crystallography. In the complex, the K+∶pic- is 1∶1, and one K(Ⅰ) ion is surrounded by six picrate anions, one picrate anion can coordinate to six K(Ⅰ) ions. The coordination number of every potassium atom is eight. Interestingly, the picratol adopts an eight-coordinated ideal mode unreported. CCDC: 630627. 相似文献
907.
A general method in considering the core electronic correlation energies has been proposed and introduced into the standard Gaussian-2 (G2)[7] theory by small post-Hartree-Fock calculations. In this paper an additional MP2(FC)/6-31G(d) calculation over the G2 procedures is employed and examined in modification in modification to the flaw of Frozen-Core (FC) approximation of G2 vai eq.:
ΔE(full)= E[MP2(full)/6-31G(d)]-E[MP2(FC)/6-31G(d)]
where the MP2(full)/6-31G(d) energy has been obtained in the molecular geometry optimizations. This energy, ΔE(full), is directly added into the total G2 energy of a molecule in facilitating the effect of core electronic correlations for each molecule in chemical reactions. It has been shown that the over-all average absolute deviation for the 125 reaction energies of the G2 test set (test set 1) is slightly reduced from 5.09 to 5.01 kJ, mol(-1) while for the 55 D0 values, which have been used for the derivation of the A coefficient of the empirical High-Level...更多-Correction (HLC), it is also reduced from 4.99 [for both G2 and G2(COMPLETE)[8]]to 4.77 kJ• mol(-1). In addition, larger errors (greater than ±8.4 kJ•mol(-1) for the D0 energies are improved, especially for the largest error of the D0 of SO2 This error is reduced from 21.3 to 15.4 kJ. mol(-1), in which the experimental geometry would further reduce it by 7.1kJ.mol(-1)[8]. Another improvement is the absolute value of the A coefficient in HLC being reduced from 4.81 for G2 to 4.34 milli-hartrees which is believed to be useful in isolating the relationship between the HLC and the FC approximation. Modifications to the original G2 from this work is denoted as G2(fu 1) and thus the G2 (fu 1) total energy for a molecule is
E[G2(fu 1)]= E[G2]+Δ E(full)h
with a new ΔE[HLC] =-0.19α- 4.34nβ milli-hartree. 相似文献
ΔE(full)= E[MP2(full)/6-31G(d)]-E[MP2(FC)/6-31G(d)]
where the MP2(full)/6-31G(d) energy has been obtained in the molecular geometry optimizations. This energy, ΔE(full), is directly added into the total G2 energy of a molecule in facilitating the effect of core electronic correlations for each molecule in chemical reactions. It has been shown that the over-all average absolute deviation for the 125 reaction energies of the G2 test set (test set 1) is slightly reduced from 5.09 to 5.01 kJ, mol(-1) while for the 55 D0 values, which have been used for the derivation of the A coefficient of the empirical High-Level...更多-Correction (HLC), it is also reduced from 4.99 [for both G2 and G2(COMPLETE)[8]]to 4.77 kJ• mol(-1). In addition, larger errors (greater than ±8.4 kJ•mol(-1) for the D0 energies are improved, especially for the largest error of the D0 of SO2 This error is reduced from 21.3 to 15.4 kJ. mol(-1), in which the experimental geometry would further reduce it by 7.1kJ.mol(-1)[8]. Another improvement is the absolute value of the A coefficient in HLC being reduced from 4.81 for G2 to 4.34 milli-hartrees which is believed to be useful in isolating the relationship between the HLC and the FC approximation. Modifications to the original G2 from this work is denoted as G2(fu 1) and thus the G2 (fu 1) total energy for a molecule is
E[G2(fu 1)]= E[G2]+Δ E(full)h
with a new ΔE[HLC] =-0.19α- 4.34nβ milli-hartree. 相似文献
908.
外加盐作用形成的正负离子表面活性剂双水相 总被引:1,自引:0,他引:1
癸基三乙基溴化铵-癸基磺酸钠(C10NE-C10SO3)等摩尔混合均相体系(即使在表面活性剂总浓度高达0.2 mol•L-1时仍然可形成稳定的均相溶液)在外加盐NaF、Na2SO4和Na3PO4的作用下可自发分离成两个水相(双水相).研究了该类双水相体系的形成、相行为及其对牛血清蛋白(BSA)的分配,并与普通的正负离子表面活性剂混合双水相体系进行了比较.结果表明,该类双水相体系克服了普通的正负离子表面活性剂混合双水相体系的一些不足,具有一些独特的优点.该类双水相体系的相行为可以通过外加盐进行调控,通过外加盐的种类来调控和优化BSA的分配行为.图1表2参8 相似文献
909.
Ag(TCNQ)准一维微米结构的制备及表征 总被引:1,自引:0,他引:1
利用溶液化学反应法制备了准一维结构的金属有机配合物Ag(TCNQ). X射线衍射(XRD)表明,所制备的Ag(TCNQ)为晶态结构;扫描电子显微镜(SEM)的观察证明,Ag(TCNQ)为准一维的微米管或线;Raman 测试结果表明,单根的Ag(TCNQ)形成时,Ag原子与TCNQ分子之间发生了电荷转移.对样品的制备工艺,即 Ag膜厚度和浸入溶液的反应时间对生成Ag(TCNQ)晶体形貌的影响进行了研究.结果表明,Ag膜越薄,生长出的晶体越稀疏;Ag膜与TCNQ乙腈溶液的反应时间影响其形貌的变化.反应历经三个阶段,晶体形成和长大阶段、反应完全阶段及溶解阶段. 相似文献
910.
TEOS-MTES基SiO2溶胶微结构的SAXS研究 总被引:3,自引:0,他引:3
正硅酸乙酯(TEOS)为前驱体,在碱性条件下制备含有无定形SiO2颗粒的溶胶,以甲基三乙氧基硅烷(MTES)在酸性条件下获得聚甲基硅氧链,二者混合后应用同步辐射X射线进行混合溶胶的SAXS散射强度测定,计算了溶胶的平均回转半径、平均粒径、两相界面层厚度、散射体体积分数、两相间比表面积等参数,辅以光子相关光谱法(PCS)和透射电子显微镜(TEM)观测溶胶粒度,证实SiO2颗粒被MTES混合物连接成族团.实验发现所测混合溶胶样品均表现出对Porod定理的负偏离,说明溶胶中颗粒与溶剂之间存在很明显的两相间界面层. 相似文献