非晶态镍硼酸盐结构的EXAFS研究

由摩尔比分别为1:2和1:8的NiCl₂·6H₂O和Na₂B₄O₇·10H₂O作为反应物, 合成两种非晶态镍硼酸盐, 同时通过水热法合成β-Ni(OH)₂. 化学分析和热重-微商热重法(TG-DTG)分析结果确定两种非晶态镍硼酸盐的分子组成分别为NiO·0.8B₂O₃·4.5H₂O和NiO·B₂O₃·3H₂O. 激光拉曼(Raman)实验结果表明镍硼酸盐样品中主要存在的硼氧阴离子为B₃O₃(OH)₅^2-和B₂O(OH)₆^2-. 同步辐射扩展X射线吸收精细结构(EXAFS)方法对样品进行结构解析, 通过数据拟合给出样品中Ni 原子周围近邻配位原子种类、配位数以及原子间距离. 用不同晶体结构作为标准对两种非晶态镍硼酸盐进行拟合的结果表明, 样品中Ni 原子周围局域结构与Ni₃B₂O₆晶体(ICSD No.31387)中的吻合较好. Ni 原子周围配位原子为O、B和Ni, 对于NiO·0.8B₂O₃·4.5H₂O, 配位数分别为5.7、3.8和3.8, 配位距离分别为0.208、0.263 和0.311 nm; 对于NiO·B₂O₃·3H₂O, 配位数分别为6.0、4.0 和4.0, 配位距离分别为0.207、0.262和0.310 nm.     

298.15 K Li2B4O7-MgCl2-H2O体系热力学性质的电动势法测定及离子相互作用模型的研究

测定了298.15 K下, 无液接电池Li-ISE│Li₂B₄O₇ (m_A)(aq.), MgCl₂(m_B)(aq.)│AgCl/Ag的电动势, 利用测定结果计算了Li₂B₄O₇-MgCl₂-H₂O体系离子强度在0.05～3 mol•kg^－1范围内, 不同MgCl₂离子强度分数的溶液中LiCl的平均活度系数, 并给出了其随离子强度I, B₄O₇^2－和Mg^2＋浓度的变化规律. 结合以往关于该体系和Li₂B₄O₇-LiCl-H₂O, Li₂B₄O₇-H₂O体系的等压研究结果, 用迭代和多元线性回归方法对Li^＋-Mg^2＋-Cl^－-B₄O₇^2－-H₂O体系的离子相互作用模型进行了研究. 具体方法为考虑了该体系在不同的总硼浓度范围H₃BO₃, B(OH)₄^－, B₃O₃(OH)₄^－和B₄O₅(OH)₄^2－四种含硼化合物的存在以及各硼化合物间的化学平衡, 以修正了的Pitzer渗透系数方程和活度系数方程为基础, 对该体系的等压法和电动势法研究结果进行最小二乘拟合, 拟合的标准偏差为0.0167, 用该模型计算的该体系的渗透系数、活度系数与实验值基本一致.     

298.15 K Li2B4O7-MgCl2-H2O体系热力学性质的电动势法测定及离子相互作用模型的研究

测定了298.15 K下, 无液接电池Li-ISE│Li₂B₄O₇ (m_A)(aq.), MgCl₂(m_B)(aq.)│AgCl/Ag的电动势, 利用测定结果计算了Li₂B₄O₇-MgCl₂-H₂O体系离子强度在0.05～3 mol•kg^－1范围内, 不同MgCl₂离子强度分数的溶液中LiCl的平均活度系数, 并给出了其随离子强度I, B₄O₇^2－和Mg^2＋浓度的变化规律. 结合以往关于该体系和Li₂B₄O₇-LiCl-H₂O, Li₂B₄O₇-H₂O体系的等压研究结果, 用迭代和多元线性回归方法对Li^＋-Mg^2＋-Cl^－-B₄O₇^2－-H₂O体系的离子相互作用模型进行了研究. 具体方法为考虑了该体系在不同的总硼浓度范围H₃BO₃, B(OH)₄^－, B₃O₃(OH)₄^－和B₄O₅(OH)₄^2－四种含硼化合物的存在以及各硼化合物间的化学平衡, 以修正了的Pitzer渗透系数方程和活度系数方程为基础, 对该体系的等压法和电动势法研究结果进行最小二乘拟合, 拟合的标准偏差为0.0167, 用该模型计算的该体系的渗透系数、活度系数与实验值基本一致.     

采用稀释成盐法从富硼浓缩盐卤中合成的镁硼酸盐化合物及其结构与性质（英文）

通过稀释成盐法在富硼浓缩盐卤体系Na-K-Mg-Cl-SO_4中合成了一种新的六硼酸镁Mg[B_6O_7(OH)_6]·5H_2O化合物。根据X射线粉末衍射数据对其晶体结构进行了精修,并采用红外及拉曼光谱法对其结构进行了表征,分析了其光谱及结构特征。结果表明,该化合物由1个Mg原子、1个B_6O_7(OH)_6基团和5个H_2O分子构成,Mg原子以六配位形式与氧结合形成畸变MgO_6八面体构型;热重分析表明,高温分解过程该化合物脱水转化为四硼酸镁MgB_4O_7;通过紫外可见漫反射法求得其禁带宽度为4.44 eV。     

MgO-B2O3-28%MgCl2-H2O体系0℃热力学非平衡态相图

采用结晶动力学方法对MgO-B₂O₃-28%MgCl₂-H₂O体系0℃时过饱和溶液的结晶过程进行了研究，结晶析出固相通过化学分析确定了组成，并用X-射线粉末衍射和红外光谱等对其进行了表征。给出了该体系0℃时的热力学非平衡态相图。该相图有4个相区，分别与H₃BO₃、MgO·3B₂O₃·7.5H₂O、2MgO·2B₂O₃·MgCl₂·14H₂O和3Mg(OH)₂·MgCl₂·8H₂O相对应。     

一个新颖镍配位阳离子修饰的还原型钼磷酸盐：Ni[Mo6O12(OH)3(PO4)(HPO4)3]2][Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O

水热合成并通过红外、热重、单晶X-射线衍射表征了一个新颖镍配位阳离子修饰的还原型钼磷酸盐,Ni[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂][Ni(H₂O)₂][Ni(H₂O)(bipy)₂]₄·5H₂O。单晶X-射线衍射研究表明,两个{Mo₆P₄}簇单元通过一个镍离子连接形成一个Ni[Mo₆P₄]₂二聚结构单元,其进一步和其他的镍配位阳离子连接成钼磷酸盐一维链状结构。在H₂O₂存在下的液－固体系中,使用该化合物催化氧化苯甲醛的探针反应结果表明,该化合物具有较高的催化氧化活性。     

新型水合稀土多硼酸盐Ln[B5O8(OH)2](Ln=Pr，Nd)的合成与结构

采用熔融硼酸法在200 ℃下合成了一种具有层状结构的新型水合稀土多硼酸盐，Ln[B₅O₈(OH)₂](Ln=Pr，Nd)，并利用粉末X射线衍射技术确定了它的结构。Ln[B₅O₈(OH)₂]晶体属于单斜晶系、P2₁/c空间群，它的基本构建单元(FBB)是由3个BO₄和2个BO₃组成的双三元环，[B₅O₁₂](2Δ+3T)。每一个FBB和邻近的4个FBB通过共用氧原子相连，形成了具有九元环窗口的层状硼酸根基团，稀土离子位于九元环中心附近。CSD：391317。     

羟基羧酸钛(Ⅲ)配合物的合成和热性质研究

三氯化钛分别与苹果酸铵、酒石酸铵和柠檬酸铵反应，制得三种新的固态配合物：苹果酸羟基钛(Ⅲ)、酒石酸羟基钛(Ⅲ)和柠檬酸钛(Ⅲ)(化学式分别为Ti(OH)(C₄H₄O₅)·1.5H₂O、Ti(OH)(C₄H₄O₆)·1.5H₂O和Ti(C₆H₅O₇)·1.5H     

盐卤硼酸盐化学 Ⅻ. MgO·3B2O3·7H2O的热行为和脱水动力学

通过对合成MgO·3B2O₃·7H₂O的热分析研究确定热脱水反应的阶段、温度和产物,给出脱水过程的热化学反应方程式.利用甲醇、水与三氧化二硼之间的酯化反应进行相分离,确定该化合物高温结晶化产物的物相组成为晶态六硼酸镁(2MgO·3B₂O₃)和无定形B₂O₃.对该化合物的TG和DTG数据进行处理结果,给出了相应的非等温热脱水反应动力学方程.     

含磷钼酸及2,2’-联吡啶-3,3’-二羧酸配体的铜配位聚合物的合成、晶体结构与电化学性质

在水热条件下合成了一个新的化合物{[Cu₄(PMo₁₂O₄₀)(H₂O)₅(H₂bpdc)(Hbpdc)(bpdc)₂]·6H₂O}_n(H₂bpdc=2, 2’-联吡啶-3, 3’-二羧酸), 并用元素分析、IR、TG和X-射线衍射等手段进行了表征。结果表明本化合物的晶体结构中, 最小不对称单元包含1个 [Cu₄(H₂O)₅(H₂bpdc)(Hbpdc)(bpdc)₂]³⁺阳离子, 1个[PMo₁₂O₄₀]^3-阴离子和6个结晶水分子。Cu(Ⅱ)与相邻[PMo₁₂O₄₀]^3-的桥氧原子配位, 形成一维链状结构。电化学研究表明, 化合物存在三步氧化还原过程。     

Structural Patterns and Dimensionality in Magnesium Borophosphates: The Crystal Structures of Mg2(H2O)[BP3O9(OH)4] and Mg(H2O)2[B2P2O8(OH)2]·H2O

Hydrothermal investigations in the system MgO/B₂O₃/P₂O₅(/H₂O) yielded two new magnesium borophosphates, Mg₂(H₂O)[BP₃O₉(OH)₄] and Mg(H₂O)₂[B₂P₂O₈(OH)₂]·H₂O. The crystal structures were solved by means of single crystal X‐ray diffraction. While the acentric crystal structure of Mg₂(H₂O)[BP₃O₉(OH)₄] (orthorhombic, P2₁2₁2₁ (No. 19), a = 709.44(5) pm, b = 859.70(4) pm, c = 1635.1(1) pm, V = 997.3(3) × 10⁶ pm³, Z = 4) contains 1D infinite chains of magnesium coordination octahedra interconnected by a borophosphate tetramer, Mg(H₂O)₂[B₂P₂O₈(OH)₂]·H₂O (monoclinic, P2₁/c (No. 14), a = 776.04(5) pm, b = 1464.26(9) pm, c = 824.10(4) pm, β = 90.25(1)°, V = 936.44(9) × 10⁶ pm³,Z = 4) represents the first layered borophosphate with 6³ net topology. The structures are discussed and classified in terms of structural systematics.     

Mg(BO2)2在MgCl2水溶液中的相平衡与化学平衡

借助拉曼光谱和X射线衍射(XRD)检测手段,对Mg(BO_2)_2在MgCl_2水溶液中水解的固液相平衡与物种化学平衡规律进行了研究。结果表明,MgCl_2对Mg(BO_2)_2的溶解转化、多硼氧配阴离子的物种分布有很大影响:(1)随着MgCl_2浓度从0达到饱和,Mg(BO_2)_2的表观饱和浓度从0.79%增加到1.96%,pH值从9.96降到6.27;(2)Mg(BO_2)_2在纯水中水解形成固相Mg_2B_6O_(11)·15H_2O和Mg(OH)_2,在MgCl_2溶液中形成固相Mg_2B_6O_(11)·15H_2O和Mg_3Cl_2(OH)_4·4H_2O;(3)Mg(BO_2)_2在纯水中水解,硼的物种主要为B_4O_5(OH)_4~(2-)和B_3O_3(OH)_4~-,分别占液相总硼含量的49.81%和19.54%。在MgCl_2饱和溶液中,主要为B_3O_3(OH)_4~-和B_5O_6OH)_4~-,分别占液相总硼含量的44.57%和40.00%。     

Hydrothermal Syntheses and Crystal Structures of Two New Heteropolyoxovanadoborates Containing {(VO)<Subscript>12</Subscript>O<Subscript>6</Subscript>[B<Subscript>3</Subscript>O<Subscript>6</Subscript>(OH)]<Subscript>6</Subscript>(H<Subscript>2</Subscript>O)} Cluster

Two new heteropolyoxovanadoborates (H₂dap)₂H₆{(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)}·13H₂O (1, dap = 1,2-diaminopropane) and {[Zn(dien)]₂[Zn(dien)(H₂O)]₄(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)}₂·15H₂O (2, dien = diethylenetriamine) have been hydrothermally synthesized and structurally characterized. Both 1 and 2 contain {(VO)₁₂O₆[B₃O₆(OH)]₆(H₂O)} cluster (denoted on V₁₂B₁₈), which is constructed by a puckered B₁₈O₃₆(OH)₆ ring sandwiched between two triangles of six alternating cis and trans edge-sharing vanadium atoms, and a central water molecule. 1 consists of discrete [V₁₂B₁₈]¹⁰⁻ cluster anions with H₂dap²⁺ as counterions, while 2 consists of discrete neutral {[Zn(dien)]₂[Zn(dien)(H₂O)]₄[V₁₂B₁₈]} clusters, which are built from two types of zinc(II) complex fragments connecting with V₁₂B₁₈ cluster through two Zn-(μ ₃-O)-B bonds. Interestingly, 2 is the only example of the V₁₂B₁₈ cluster decorated by two types of zinc(II) complex fragments.     

Two new transition metal inorganic–organic hybrid borates: [tris(2‐aminoethoxy)trihydroxyhexaborato]cobalt(II) and its nickel(II) analogue

The two isomorphous title compounds, [1,5,9‐tris(2‐aminoethoxy)‐3,7,11‐trihydroxy‐3,7,11‐tribora‐1,5,9‐triborata‐2,4,6,8,10,12‐hexaoxa‐13‐oxoniatricyclo[7.3.1.0^5,13]tridecane]cobalt(II), [Co(C₆H₂₁B₆N₃O₁₃)] or Co{B₆O₇(OH)₃[O(CH₂)₂NH₂]₃}, and the Ni^II analogue, [Ni(C₆H₂₁B₆N₃O₁₃)], each consist of an M^II cation and an inorganic–organic hybrid {B₆O₇(OH)₃[O(CH₂)₂NH₂]₃}²⁻ anion. The M^II cation lies on a crystallographic threefold axis (as does one O atom) and is octahedrally coordinated by three N atoms from the organic component. Three O atoms covalently link the B–O cluster and the organic component. Molecules are connected to one another through N—H...O and O—H...O hydrogen bonds, forming a three‐dimensional supramolecular network.     

Mg7(AsO4)2(HAsO4)4: a new magnesium arsenate with a very strong hydrogen bond

A new compound, heptamagnesium bis­(arsenate) tetrakis(hydrogenarsenate), Mg₇(AsO₄)₂(HAsO₄)₄, was synthesized by a hydro­thermal method. The structure is based on a three‐dimensional framework of edge‐ and corner‐sharing MgO₆, MgO₄(OH)₂, MgO₅, AsO₃(OH) and AsO₄ polyhedra. Average Mg—O and As—O bond lengths are in the ranges 2.056–2.154 and 1.680–1.688 Å, respectively. Each of the two non‐equivalent OH groups is bonded to both an Mg and an As atom. One OH group is involved in a very short hydrogen bond [O⋯O = 2.468 (3) Å]. The formula unit is centrosymmetric, with all atoms in general positions except for one Mg atom, which has site symmetry . The compound is isotypic with Mn₇(AsO₄)₂(HAsO₄)₄ and M₇(PO₄)₂(HPO₄)₄, where M is Fe, Co or Mn.     

Oxidopolyborate chemistry: The self-assembled,templated, synthesis,and an XRD study of a 1-D coordination polymer, [Cu(en){B6O7(OH)6}].3H2O (en = 1,2-diaminoethane)

Abstract

[Cu(en){B₆O₇(OH)₆}]^.3H₂O (1) (en = 1,2-diaminoethane), obtained as a crystalline solid in low yield (31%) after prolonged standing of an aqueous solution initially containing [Cu(en)₂](OH)₂ and B(OH)₃ (1:7 ratio), was characterized by thermal analysis (TGA/DSC), ¹¹B NMR and IR spectroscopy, powder XRD, and single-crystal XRD studies, and magnetic susceptibility measurements. The single-crystal X-ray diffraction revealed that the oxidoborate complex is a 1D coordination polymer with the hexaborate(2-) ligand bridging two hexacoordinate Cu^(II) centers, in an alternating a fac-tridentate (κ³-O) and monodentate (κ¹-O) arrangement. Cu-O coordination bonds and extensive H-bonding networks promote and stabilize the self-assembly of [Cu(en){B₆O₇(OH)₆}]^.3H₂O from the Dynamic Combinatorial Libraries of available reactants. [Cu(en){B₆O₇(OH)₆}]^.3H₂O is thermally decomposed to CuB₆O₁₀ in air at 700?°C.     

(Ni3–xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5): A Novel BorophosphateHydrate Containing Isolated Six‐Membered Rings of Tetrahedra

A novel borophosphate‐hydrate, (Ni_3–xMg_x)[B₃P₃O₁₂(OH)₆] · 6 H₂O (x ≈ 1.5), has been prepared by hydrothermal synthesis (T = 170 °C) from a mixture of NiCl₂ · 6 H₂O, Mg(OH)₂, B₂O₃ and H₃PO₄. The crystal structure was determined at 293 K from single‐crystal X‐ray diffraction data (trigonal, R3c (no. 167), a = 14.957(10) Å, c = 13.812(6) Å, V = 2676(2) ų, Z = 6, R₁ = 0.0276, wR₂ = 0.0714 for 779 observed reflections with I > 2σ(I)). The crystal structure contains unbranched six‐membered rings [B₃P₃O₁₂(OH)₆]^6– of alternating corner linked borate and phosphate tetrahedra, which are stacked along [001] and connected via M^IIO₂(OH)₂(H₂O)₂ coordination polyhedra. Hydrogen bonding between the tetrahedral six‐membered rings and M^IIO₂(OH)₂(H₂O)₂ octahedra leads to a further cross‐linking. With respect to the arrangement of isolated six‐membered tetrahedral rings the crystal structure of this borophosphate‐hydrate is closely related to the cyclo‐hexasilicate dioptase, Cu₆[Si₆O₁₈] · 6 H₂O.     

Studies on synthesis, characterization and thermochemistry of Mg2[B2O4(OH)2]·H2O

A new magnesium borate Mg₂[B₂O₄(OH)₂]·H₂O has been synthesized by the method of phase transformation of double salt at hydrothermal condition and characterized by XRD, IR, TG and DSC. The enthalpy of solution of Mg₂[B₂O₄(OH)₂]·H₂O in 0.9764 mol L^–1 HCl was determined. With the incorporation of the enthalpies of solution of H₃BO₃ in HCl (aq), of MgO in (HCl+H₃BO₃) (aq), and the standard molar enthalpies of formation of MgO(s), H₃BO₃(s), and H₂O(l), the standard molar enthalpy of formation of –(3185.78±1.91) kJ mol^–1 of Mg₂[B₂O₄(OH)₂]·H₂O was obtained.This revised version was published online in November 2005 with corrections to the Cover Date.     

A New Organic‐Inorganic Hybrid Copper Pentaborate with Free Boric Acid Group

The hydrothermal reaction of Cu(CH₃COO)₂·H₂O, H₃BO₃, ethylenediamine and H₂O in a molar ratio of 3:20:9:222 at 140°C for 5 d yields the deep blue crystals of a new copper polyborate [Cu(en)₂B(OH)₃]· [B₅O₅(OH)₇] (en?H₂NCH₂CH₂NH₂) in 70% yield. It crystallizes in monoclinic system, space group P2₁/c, with unit cell dimensions, a=1.2779(2) nm, b=1.0167(15) nm, c=1.5019(2) nm, β=90.30(2)°, Z=4. The crystal structure of this compound consists of [Cu(en)₂B(OH)₃]²⁺ cation and [B₅O₅(OH)₇]^2? anion, which are linked together through hydrogen bonding interactions and electrostatic forces, forming an interesting three‐dimensional framework. The [B₅O₅(OH)₇]^2? anion is constituted of [B₄O₅(OH)₄]^2? anion and discrete B(OH)₃ group which attaches to the side of [B₄O₅(OH)₄]^2? through intramolecular hydrogen bonds. Fundamental vibrational modes of this compound were identified and band assignments were made. The middle bands observed at 882 and 575 cm^?1 in Raman spectrum are the characteristic peak of B(OH)₃ group and [B₄O₅(OH)₄]^2? anion, respectively. Additionally the thermal behavior of title compound was recorded and its decomposition mechanism was discussed.     

过渡金属硼酸盐K7{(BO3)Zn[B12O18(OH)6]}·H2O的合成与量子化学研究

通过水热的方法合成了一例新的过渡金属硼酸盐K7{(BO3)Zn[B12O18(OH)6]}·H2O(1),并对其进行了红外,热重,能谱以及X-射线单晶衍射和粉末衍射分析。晶体学测试结果表明,化合物1属于正交晶系,Pmn21空间群,晶胞参数a=1.236 51(4)nm,b=0.909 61(3)nm,c=1.304 05(5)nm,V=1.466 72(9)nm3,Z=2,R1=0.049 7,wR2=0.146 8。对{(BO3)Zn[B12O18(OH)6]}7-阴离子簇的量化分析显示此簇中的端基BO3基团对前线分子轨道的贡献最大。除端O原子外,BO3端基的原子电荷较其它B和O原子电荷低。