5水合甘氨酸复合体的结构和性能的理论研究

为了探讨“几个水分子导致甘氨酸两性离子复合体与其中性分子复合体等能”, 采用mp2/6-31＋＋g**//b3lyp/6- 31＋＋g**方法研究了甘氨酸水化的微观机理, 发现答案是5个水分子, 并证实了实验结果. 最稳定的5水合甘氨酸两性离子复合体具有双链结构, 与最稳定的5水合甘氨酸中性分子复合体能量接近(仅相差2.26 kJ/mol), 能够共存; 中性复合体和两性复合体之间可以通过直接质子迁移和桥助质子迁移等两种途径相互转化, 双链结构的甘氨酸复合体中质子迁移的能垒较低甚至无垒, 能够自发进行.     

Structure of an I- x (H2O)6 anion cluster in a 3D anion crystal host [I x (H2O)6Fe(CN)6 x H2O]4-

A planar structure of an anion cluster I- x (H2O)6 in a 3D supramolecular complex [Ru(bpy)3]2[I x (H2O)6Fe(CN)6 x H2O] has been determined by single-crystal X-ray analysis. In the supramolecule, the anion cluster I- x (H2O)6, together with the anion [Fe(CN)6 x H2O]2-, acts as a 3D crystal host, and the [Ru(bpy)3]2+ cations, as the guest molecules, occupy the vacancies of the 3D host framework. This is the first crystal example of the anion cluster I- x (H2O)6.     

Structure of the O2 −·(H2O)5 cluster ion

Odessa Refrigeration Technology Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 4, pp. 137–138, July–August, 1990.     

Synthesis,Structure and Characterization of Three Metal Molybdate Hydrates: Fe(H2O)2(MoO4)2·H3O,NaCo2(MoO4)2(H3O2)and Mn2(MoO4)3·2H3O

Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray...     

[Gd(Gly)3(H2O)2]Cl3·H2O的合成与晶体结构

氯化钆;甘氨酸;固态配合物;[Gd(Gly)3(H2O)2]Cl3·H2O的合成与晶体结构     

Density functional study of HO(H2O)n (n = 1–3) clusters

The hydrogen bonding complexes HO(H₂O)_n (n = 1–3) were completely investigated in the present study using DFT and MP2 methods at varied basis set levels from 6‐31++G(d,p) to 6‐311++G(2d,2p). For n = 1 two, for n = 2 two, and for n = 3 five reasonable geometries are considered. The optimized geometric parameters and interaction energies for various complexes at different levels are estimated. The infrared spectrum frequencies and IR intensities of the most stable structures are reported. Finally, thermochemistry studies are also carried out. The results indicate that the formation and the number of hydrogen bonding have played an important role in the structures and relative stabilities of different complexes. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Synthesis and Crystal Structure of （H3O）2[Cu3Cl3（H2O）3（NC9H12.5O6）2]

1 INTRODUCTION The polydentate ligand nitrilotripropionic acid, H3ntp[N(CH2CH2COOH)3], has attracted conside- rable research interest in constructing coordination polymers, designing organic-inorganic hybrid mate- rials[1], synthesizing supramolecular compounds[2], etc. due to its high degree of flexibility with three carboxylic acid moieties allowing for a variety of coordination through oxygen atoms[3]. It also pro- vides other versatile properties such as the possibili- ty of inter-…     

Dissociation and IVR pathways for the CF3H(H2O)3 cluster

Classical trajectory simulations are used to study the intramolecular dynamics of isolated CF₃H and the CF₃H(H₂O)₃ cluster, by either exciting the CH stretch local mode to then=6 level or by adding an equivalent amount of energy to an OH stretch normal mode. Energy transfer from the CH local mode is statistically the same for CF₃H(H₂O)₃ as for isolated CF₃H, and agrees with previous experimental studies. Clusters excited with 6 quanta in the CH local mode are remarkably stable. Though the CF₃H-(H₂O)₃ intermolecular potential is only 1.5 kcal/mol, only 1 of 26 clusters excited with 6 quanta in the CH local mode dissociate within 10 ps. The absorption linewidth for the CH local mode in CF₃H(H₂O)₃ is related to IVR within CF₃H and not to the unimolecular lifetime of the cluster. When an OH stretch normal mode of the cluster is excited, energy transfer to CF₃H is negligible and nearly one half of the clusters dissociate within 10 ps.     

配合物Nd(C7H7N2O2)3(H2O)3的合成及其晶体结构

用水热法合成了3,5-二氨基苯甲酸与Nd(Ⅲ)的配合物Nd(C7H7N2O2)3(H2O)3(1),其结构经IR,元素分析和X-射线单晶衍射仪表征。1为单核结构,属六方晶系,R3空间群,晶胞参数:a=1.887 29(18)nm,b=1.887 29(18)nm,c=0.603 53(12)nm,β=90,°γ=120°,V=1.861 7(4)nm3,Z=3,μ=2.154 mm-1,Dc=1.744 g.cm-3,R1=0.014 3,wR2=0.033 2。1中Nd(Ⅲ)与来自3个3,5-二氨基苯甲酸的6个氧原子及3个配位水的氧原子进行配位,形成9配位化合物。     

Two scandium–biuret complexes: [Sc(C2H5N3O2)(H2O)5]Cl3·H2O and [Sc(C2H5N3O2)4](NO3)3

The scandium(III) cations in the structures of pentaaqua(biuret‐κ²O,O′)scandium(III) trichloride monohydrate, [Sc(C₂H₅N₃O₂)(H₂O)₅]Cl₃·H₂O, (I), and tetrakis(biuret‐κ²O,O′)scandium(III) trinitrate, [Sc(C₂H₅N₃O₂)₄](NO₃)₃, (II), are found to adopt very different coordinations with the same biuret ligand. The roles of hydrogen bonding and the counter‐ion in the establishment of the structures are described. In (I), the Sc³⁺ cation adopts a fairly regular pentagonal bipyramidal coordination geometry arising from one O,O′‐bidentate biuret molecule and five water molecules. A dense network of N—H...Cl, O—H...O and O—H...Cl hydrogen bonds help to establish the packing, resulting in dimeric associations of two cations and two water molecules. In (II), the Sc³⁺ cation (site symmetry 2) adopts a slightly squashed square‐antiprismatic geometry arising from four O,O′‐bidentate biuret molecules. A network of N—H...O hydrogen bonds help to establish the packing, which features [010] chains of cations. One of the nitrate ions is disordered about an inversion centre. Both structures form three‐dimensional hydrogen‐bond networks.