Hydrothermal syntheses and characterizations of two new hydrogen bond-supported supramolecular compounds based on polyoxometalates

Two new polyoxometalates [HN(C₂H₅)₃]₃[PMo₁₂O₄₀] (1) and [NH₂(C₂H₄NH₃)₂]₂[Mo₅P₂O₂₃] (2) have been hydrothermally synthesized and characterized by IR, UV-Vis, XPS spectra, TG analyses, and single crystal X-ray diffraction. Crystal data for 1: monoclinic, space group C2/c, a = 24.651(5) Å, b = 10.822(2) Å, c = 22.413(5) Å, β = 120.37(3)°, and V = 5158.7(18) ų; for 2: triclinic, space group P-1, a = 9.821(2) Å, b = 9.948(2) Å, c = 14.687(3) Å, α = 95.490(3)°, β = 98.870(3)°, γ = 95.710(3)°, and V = 1401.7(5) ų. The crystal structure analyses reveal complex hydrogen bonds in both 1 and 2 in 3-D supramolecular arrays constructed from different polyoxoanions and organic ligands.     

Two new hydrogen bond-supported supramolecular compounds assembly from arsenic vanadates and [M(H2O)6] cations (MCo, Ni)

Two new supramolecular compounds based on arsenic vanadates formulated as [H₂As₆V₁₅O₄₂(H₂O)][Co(H₂O)₆]₂·2H₂O (1) and [H₂As₆V₁₅O₄₂(H₂O)][Ni(H₂O)₆]₂·2H₂O (2) have been prepared by reacting V₂O₅, H₂C₂O₄·2H₂O, As₂O₃,·H₂SO₄, CoCl₂·6H₂O (NiSO₄·6H₂O) and enMe (enMe=1,2-diaminopropane) under mild hydrothermal conditions and characterized by elemental analyses, IR, ESR, XPS and single crystal X-ray diffraction analyses. Crystal structure analyses reveal that compounds 1 and 2 are isostructural and exhibit novel 2-D supramolecular layer structures constructed from arsenic-vanadium clusters and two different types of secondary building units (SBUs), respectively, the different SBUs are formed by joint of two adjacent [Co(H₂O)₆]²⁺ cations in compounds 1 and [Ni(H₂O)₆]²⁺ cations in 2, respectively.     

一维链状[Mn(9-AC)2(4,4'-bpy)(H2O)2]n配位聚合物的合成及晶体结构

在水热条件下(120 ℃), 将醋酸锰、4,4'-联吡啶(4,4'-bpy)与9-蒽酸(9-HAC)反应, 得到了配位聚合物[Mn(9-AC)2(4,4'-bpy)(H2O)2]n, 通过元素分析、红外光谱、X射线单晶衍射对其进行了表征, 并用TGA研究了该配位聚合物的热稳定性. 结构解析结果表明, 该晶体属于正交晶系, Fdd2空间群, a=1.66772(12) nm, b=3.36471(16) nm, c=1.1687(4) nm, V=6.558(2) nm3, Z=8, Mr=689.60, Dc=1.397 Mg/m3, R=0.0356, wR2 = 0.0604. 在该配位聚合物中, 中心锰原子采取略微变形的八面体构型, 与两种配体共同构筑了一维直线形链结构, 链与链之间通过氢键相互作用构筑成三维超分子网络.     

一维链状[Mn(9-AC)_2(4,4′-bpy)(H_2O)_2]_n配位聚合物的合成及晶体结构

在水热条件下(120℃),将醋酸锰、4,4′-联吡啶(4,4′-bpy)与9-蒽酸(9-HAC)反应,得到了配位聚合物[Mn(9-AC)2(4,4′-bpy)(H2O)2]n,通过元素分析、红外光谱、X射线单晶衍射对其进行了表征,并用TGA研究了该配位聚合物的热稳定性.结构解析结果表明,该晶体属于正交晶系,Fdd2空间群,a=1.66772(12)nm,b=3.36471(16)nm,c=1.1687(4)nm,V=6.558(2)nm3,Z=8,Mr=689.60,Dc=1.397Mg/m3,R=0.0356,wR2=0.0604.在该配位聚合物中,中心锰原子采取略微变形的八面体构型,与两种配体共同构筑了一维直线形链结构,链与链之间通过氢键相互作用构筑成三维超分子网络.     

Synthesis of dinitrosyl iron complexes (DNICs) with intramolecular hydrogen bonding

HSCH₂CONHCH₃ and HSCH₂CON(CH₃)₂ containing a peptide bond are prepared for the synthesis of DNICs with/without intra-molecular hydrogen bonding, respectively. The IR ν(NO) bands of [(NO)₂Fe(SCH₂CONHCH₃)₂]⁻ (2) appears at 1751, 1700 cm⁻¹. In complex 2, the presence of intramolecular [NH?S] hydrogen bonding was verified by the observation of IR spectroscopy with N−H stretching frequency 3334 cm⁻¹ (CDCl₃) and subsequently confirmed by single-crystal X-ray diffraction showing N−S distance of 2.94 Å. Complex 2 displays the rhombic EPR spectrum with g₁ = 2.039, g₂ = 2.031 and g₃ = 2.013 at in frozen H₂O. Complexes 2 and 3 rapidly release NO when exposed to light. The time needed for photolysis reactions of 2 is two times faster than that of 3 in less polar solvent. Representative time courses for the photolability of 2 and 3 in THF display the NO-off ability: 2 > 3.     

一个新的二氮六元杂环化合物的合成、结构及表征

二氮杂环化合物及其衍生物在配合物的自组装和生物无机等领域中具有诱人的研究前景,因而引起各国化学家的广泛关注．这类化合物的合成可以追溯到60年前,Buhle等首次合成了1,5-二氮环辛烷(DACO)．随后,其一系列衍生物也被合成出来,并应用于配位化学及相关领域的研     

Formation of [FeW12O40]5− under hydrothermal conditions: syntheses,crystal structures,and characterization of [Fe(2,2′-bipy)3]2[HFeW12O40] · 5H2O and (4,4′-H2bipy)6(Hpy)2(H3O)[FeW12O40]3 · 11H2O

Two supramolecular compounds based on tungstoferrate [FeW₁₂O₄₀]^5?, [Fe^II(2,2′-bipy)₃]₂[HFeW₁₂O₄₀] · 5H₂O (1), and [Hpy]₂[4,4′-H₂bipy]₆(H₃O)[FeW₁₂O₄₀]₃ · 11H₂O (2) (py = pyridine, bipy = bipyridine) were synthesized hydrothermally and characterized structurally. The hydrogen bonds between polyoxoanions and water and the edge-to-face π–π interaction between [Fe^II(2,2′-bipy)₃]²⁺ with a shortest C–C distance of 3.513 Å are the main forces to construct the 3-D architecture of 1. In 2, a 3-D supramolecular architecture is assembled by the tungstoferrate anions, protonated 4,4′-bipy cations, and water through hydrogen bonding. The variable-temperature magnetic susceptibilities indicate that 1 is paramagnetic with μ _eff corresponding to one Fe(III) with spin-only contribution, showing that Fe in the coordination cations has a +II oxidation number and low spin state.     

Density functional theory study on the –SO3H functionalized acidic ionic liquids

In this work, the structures of the –SO₃H functionalized acidic ionic liquid 1-(3-sulfonic acid) propyl-3-methylimidazolium hydrogen sulfate ([C₃SO₃Hmim]HSO₄), including its precursor compound (zwitterion), cation, and cation–anion ion-pairs, were optimized systematically by the DFT theory at B3LYP/6-311++G** level, and their most stable geometries were obtained. The calculation results indicated that a great tendency to form strong intramolecular hydrogen bonds was present in the zwitterion, and this tendency was weakened in the cation that was the protonation product of zwitterion. The intramolecular hydrogen bonds and intermolecular hydrogen bonds coexisted in the ionic liquid, and they played an important role in the stability of the systems. The strongest interaction in the ionic liquid was found between the anion and the functional group. The transition state research and the intrinsic reaction coordinate analysis of the hydrogen transfer reaction showed that, when the cation and the anion interacted near the functional group by double O–H···O hydrogen bonds, the ionic liquid was inclined to exist in a form of the zwitterion and H₂SO₄.     

Hydrothermal synthesis and characterization of (enH2)3.5[As8V14O42(PO4)]·2H2O

The compound (enH₂)_3.5[As₈V₁₄O₄₂(PO₄)]·2H₂O 1 (en=ethylenediamine) has been synthesized and characterized by means of elemental analysis, IR spectrum, ESR spectrum, XPS spectrum, TG analysis and single crystal X-ray diffraction analysis. The compound 1 crystallizes in monoclinic system, space group C2/c, β=105.59(3), Z=8 and R₁(wR₂)=0.0398(0.0885). The compound 1 is constructed from [As₈V₁₄O₄₂(PO₄)]⁷⁻ anions and H₂en cations linked through hydrogen bonds into a network. The [As₈V₁₄O₄₂(PO₄)]⁷⁻ cluster consists of 14 VO₅ square pyramids linked by 4 As₂O₅ handle-like units, and includes at its center an ordered PO₄³⁻ anion.     

Cu2(bipy)2V6O17: A new type of layered inorganic–organic hybrid copper(II) vanadate

Hydrothermal reaction of copper(II) acetate, 2,2′-bipyridine (bipy) and NH₄VO₃ at 170 °C lead to a new layered polyoxovanadate with organically covalent-bonded copper(II) complex, Cu₂(bipy)₂V₆O₁₇ (1). Cu₂(bipy)₂V₆O₁₇ (1) is a new copper(II) vanadium(V) oxide featuring a new layered architecture, in which the V₂O₇ dimeric units and the cyclic tetranuclear V₄O₁₂ cluster units are interconnected via corner sharing into a unique one-dimensional {V₆O₁₇}⁴⁻ anionic chain, such chains are further bridged by {Cu(bipy)}²⁺ complex cations into a 010 organic–inorganic hybrid layer.     

锂在共轭双键高分子中的电化学嵌入反应III. 锂嵌入聚噻吩的量子化学计算†

采用Gaussian软件和HF方法, 通过从头计算(ab initio)法选取4-31G基组计算锂离子嵌入聚噻吩过程中结构与结合能的变化关系. 发现噻吩聚合时主要生成三或四聚合物. 聚合物在Li原子(或Li^＋离子)嵌入后, 聚噻吩间距离明显变小, 同时发生电荷转移, 形成稳定嵌合物; 并使噻吩环的C-α—C-β键级变小. 同时, 研究了锂离子(或原子)嵌入后体系的HOMO, LUMO能级. 聚噻吩在嵌入锂离子时LUMO轨道能级变为负值, 成为电池反应得电子的正极. 而金属Li₂ 释放Li^＋后的Li^－的HOMO能级为＋0.7427 eV, 则成为给电子的负极. 由此, 可以完成由锂/聚噻吩在高氯酸锂电解质中组成的放电过程, 并提出嵌合键级概念用来表征锂在聚噻吩间的结合程度.     

多肽中氢键强度的理论研究

用B3LYP/6-31G^*法优化了多肽分子的几何构型,计算了各个构型的电荷分布和氢键酸度,进而对多肽分子中的氢键强度进行了研究.结果表明,多肽分子中氢键的强度同时取决于形成氢键的H…O原子间距R和N-H…O之间的键角β;多肽分子倾向于形成R值小、β值大的大环氢键.3₁₀螺旋结构的多肽分子中的氢键具有协同效应,分子越大,分子中氢键越多,氢键的协同效应越强.     

Synergistic effects of a specific metal template and H-bonds in controlling macrocyclization: a simple, selective, and effective cyclization from N,N-bis(2-hydroxybenzyl)alkylamine derivatives

A macrocyclic compound obtained from a simple, selective, and effective reaction between N,N-bis(2-hydroxybenzyl)alkylamine derivatives and 1,3-bis(tosyloxy)propane is a good example of a cyclization controlled by synergistic effects of a metal template and hydrogen bonds.     

三维氢键超分子化合物[H3cth][Fe(CN)6]·3H2O的合成与结构

用内消旋５,７,７,１２,１４,１４－六甲基－１,４,８,１１－四氮杂环十四烷（ｃｔｈ）和Ｋ_３［Ｆｅ（ＣＮ）_６〕合成了氢键连接的超分子化合物［Ｈ_３ｃｔｈ］［Ｆｅ（ＣＮ）_３］·３Ｈ_２Ｏ．该化合物的晶体属三斜晶系,Ｐ－１空间群,晶胞参数ａ＝０．９３０ ９７（９）ｎｍ,ｂ＝１．０５１ ６０（１１）ｎｍ,ｃ＝１．６３８ ４７（１７）ｎｍ,ａ＝１０１．０７７（２）°,β＝９０．８６０（２）°,γ＝１１１．６７１（２）°, Ｖ＝１．４５６ ４（３） ｎｍ３, Ｚ＝２, Ｒ＝０．０４１５．晶体中质子化的大环四胺与六氰合铁（Ⅱ ）离子之间通过氢键连接成二维层状结构,而水分子所形成的氢键使化合物呈现三维超分子网络．     

Characterization of two linear chain compounds: Ferromagnet NiCl2(CH3OH)2(1,4-dioxane)0.5 (1) and paramagnet [NiCl2(H2O)2(1,4-dioxane)](1,4-dioxane) (2)

The solvent-mediated crystal-to-crystal transformation was observed from yellow crystal of NiCl₂(CH₃OH)₂(1,4-dioxane)_0.5 (1) to green crystal of [NiCl₂(H₂O)₂(1,4-dioxane)](1,4-dioxane) (2) under high humidity or adding of H₂O in CH₃OH/1,4-dioxane solution. The μ-Cl₂ bridge in 1 replaced by 1,4-dioxane bridge in 2. In 1, the chlorine-bridged linear chains of NiCl₂(CH₃OH)₂ and 1,4-dioxane molecules stack along the b- and c-axis alternatively with hydrogen bonds intrachain, interchain, between chain and solvent. These hydrogen bonds and dipolar interaction between ferromagnetic coupling chlorine-bridged chains result in long-range ferromagnetic ordering at 3.1 K and a strong frequency dependence of the ac-susceptibilities associated to domain structures with very large shape anisotropy was observed below 3.1 K. In 2, layers of 1,4-dioxane-bridged linear chains of NiCl₂(H₂O)₂(1,4-dioxane) are intercalated by layer of 1,4-dioxane molecules with hydrogen bonds between chain and solvent. Compound 2 is paramagnet to 2 K.     

尿素及硫脲与羰基化合物间的氢键相互作用

利用量子化学二级微扰理论方法对尿素及硫脲衍生物与羰基化合物之间的氢键复合物进行了研究, 在自然键轨道分析基础上进一步揭示了氢键本质并研究了取代基效应. 结果表明, 羰基化合物中供电子基和共轭基, 尿素及硫脲中的吸电子基和共轭基均有利于氢键的形成. 结合尿素与硫脲的催化反应过程, 讨论了氢键复合物两种可能的顺反异构并分析比较了顺反式构象异构体的稳定能大小.     

Synthesis,structural characterization,and properties of two new polyoxovanadates based on decavanadate [V10O28]6−

Two new decavanadate metal compounds, [Co(pyim)₃]₂[V₁₀O₂₈]·7H₂O (1) and [Ni(pyim)₃]₂[H₂V₁₀O₂₈]·4H₂O (2) (pyim?=?2-(2-pyridyl)-imidazole), have been synthesized under hydrothermal conditions and characterized by elemental analysis, single-crystal X-ray diffraction analysis, infrared spectra, powder X-ray diffraction analysis, and thermogravimetric analysis. Crystallographic analysis reveals that 1 is constructed from [V₁₀O₂₈]^6?, metal cation [Co(pyim)₃]³⁺, and water. [V₁₀O₂₈]^6? clusters are connected by waters through O–H?O hydrogen bonds to form a sheet structure which is further connected by N–H?O hydrogen bonds to form a 3-D supermolecular framework. In 2, although [Ni(pyim)₃]²⁺ is similar to [Co(pyim)₃]³⁺ in 1, the M?O cluster anion is protonated [H₂V₁₀O₂₈]^4?.     

Synthesis and structure of polyhydroxyl rigid triangular nano-macrocyclic imine having multiple hydrogen-bonding sites

42-Membered macrocyclic oligoimines based on the rigid biphenyl framework with 12 hydroxyl groups directing inward were synthesized by six-component cyclization without using a template. In the crystalline state, six dimethylsulfoxide molecules are bound simultaneously in a nano-sized cavity via hydrogen bonds.