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1.
郭鸿旭  王庆华  陈晨  梁敏  陈铃 《中国化学》2008,26(4):640-644
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。  相似文献   

2.
The calcium salts Ca2P2O6 · 2H2O ( 1 ) and [Ca(H2O)3(H2P2O6)] · 0.5(C12H24O6) · H2O ( 2 ) were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pbca and compound 2 in the monoclinic space group P21/n. The crystal structure of compound 1 consists of chains of edge‐sharing [CaO7] polyhedra linked by hypodiphosphate(IV) anions to form a three‐dimensional network. The crystal structure of compound 2 consists of alternated layers of crown ether and water molecules and respective ionic units. Within the layers of ionic units the Ca2+ cations are octahedrally coordinated by three monodentate dihydrogenhypodiphosphate(IV) anions and three water molecules. The IR/Raman spectra of the title compounds were recorded and interpreted, especially with respect to the [P2O6]4– and [H2P2O6]2– groups. The phase purity of 2 was verified by powder diffraction measurements.  相似文献   

3.
利用水热法合成了两种过渡金属配合物为模板剂的含水硼酸盐晶体Co(en)3[B4O5(OH)4]Cl·3H2O(1) 和 [Ni(en)3][B5O6(OH)4]2·2H2O (2),并通过元素分析、X射线单晶衍射、红外光谱及热重分析对其进行了表征。化合物1晶体结构的主要特点是在所有组成Co(en)33+, [B4O5(OH)4]2–, Cl– 和 H2O之间通过O–H…O、O–H…Cl、N–H…Cl和N–H…O四种氢键连接形成网状超分子结构。化合物2晶体结构的特点是[B5O6(OH)4]–阴离子通过O–H…O氢键连接形成沿a方向有较大通道的三维超分子骨架,模板剂[Ni(en)3]2+阳离子和结晶水分子填充在通道中。  相似文献   

4.
The asymmetric unit of the title compound consists of two crystallographically independent, but structurally identical, [HP2Mo5O23]5− anions, ten guanidinium cations and five water molecules. Each singly protonated diphosphopentamolybdate(VI) anion retains the typical geometry of a ring of five edge‐sharing MoO6 octahedra [Mo...Mo = 3.3265 (8)–3.4029 (10) Å], except for one corner‐sharing link [Mo...Mo = 3.6642 (7) and 3.6826 (8) Å]. Two capping PO4 tetrahedra share corners with the five octahedra. Despite being surrounded by an extensive network of hydrogen bonds, predominantly from the guanidinium cations, short P—O—H...O=P contacts [O...O = 2.519 (7) and 2.457 (7) Å] associate the anions into infinite columns generated by the c‐glide. In addition to their heavy involvement in hydrogen bonding, with all N—H donors being utilized, the guanidinium cations assemble into extensive π‐stacked columns with an average interplanar spacing of 3.53 Å.  相似文献   

5.
The title compound, hexa­ammonium tetra‐μ3‐selenido‐tetra­kis­(tri­cyano­molybdenum) hexahydrate, is isostructural with the Mo/S, W/S and W/Se analogues. The structure contains disordered cyclic hydrogen‐bonded [{(NH4)(H2O)}3]3+ cations and [Mo4Se4(CN)12]6? cluster anions with 3m symmetry. The cation assembly consists of alternating ammonium and water mol­ecules linked by N—H?O hydrogen bonds. The anion has a typical cubane cluster structure. The cations and anions are linked together by hydrogen bonds involving the terminal N atoms of the CN groups.  相似文献   

6.
The salts [Cu(phen)3][Cu(pheida)2]·10H2O ( 1 ) and [(phen)2Cu(μ‐BAAP)Cu(μ‐BAAP)Cu(phen)2][Cu(BAAP)2]·8.5H2O ( 2 ) (H2pheida = N‐phenetyl‐iminodiacetic acid, H2BAAP = N‐benzylaminoacetic‐2‐propionic acid, phen = 1, 10‐phenanthroline) have been prepared and studied by thermal, spectroscopic and X‐ray diffraction methods. 1 has the rather unusual [Cu(phen)3]2+ cation and two non‐equivalent [Cu(pheida)2]2— anions with a coordination type 4+2 but quite different tetragonality (T = 0.848 and 0.703 for anions 1 and 2, respectively). The crystal consists of multi‐π, π‐stacked chains (…anion 2 — cation — cation — anion 2…) connected by hydrophobic interactions; these chains build channels which are partially filled by anions 1 and water molecules. In contrast, compound 2 has a mixed‐ligand trinuclear cation with a bridging central moiety close similar to the counter anion. The formation of such a trinuclear cation is discussed as a consequence of the most advantageous molecular recognition process between [Cu(phen)2(H2O)1 or 2]2+ and [Cu(BAAP)2]2— in solution. In the crystal of 2, multi‐π, π‐stacked arrays of C6‐rings from phen and (BAAP)2— ligands of trinuclear cations generate channels where counter anions and water molecules are located.  相似文献   

7.
Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH and (C18H36N2O6Na)2[Mo6Cl8(OC6H5)6] . The reaction of Na2[Mo6Cl8(OCH3)6] and 2,2,2-crypt yields (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6 CH3OH ( 1 ), which is converted to (C18H36N2O6Na)2[Mo6Cl8(OC6H5)6] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo6Cl8i(ORa)6]2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo6Cl8(OC6H5)6]2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.  相似文献   

8.
A novel polymer (NH4)6[Ce(H2W12O40)(C4H2O4)(NO3)(H2O)3] ( 1 ) has been constructed at room temperature and characterized by single crystal X‐ray structural analyses, elemental analyses, cyclic voltammetry, IR spectrum, and thermogravimetry. X‐ray structural analysis reveals that through the W–Ot′–Ce–Ob–W linkages a one‐dimension infinitely linear chain with alternating cations and anions is formed. 1 represents the first characterized compound that the Ce3+ ions are coordinated by four different types of ligands, and maleinate as ligands in constructing LnPOM architecture.  相似文献   

9.
The Lanthanum Dodecahydro‐closo‐Dodecaborate Hydrate [La(H2O)9]2[B12H12]3·15 H2O and its Oxonium‐Chloride Derivative [La(H2O)9](H3O)Cl2[B12H12]·H2O By neutralization of an aqueous solution of the free acid (H3O)2[B12H12] with basic La2O3 and after isothermic evaporation colourless, face‐rich single crystals of a water‐rich lanthanum(III) dodecahydro‐closo‐dodecaborate hydrate [La(H2O)9]2[B12H12]3·15 H2O are isolated. The compound crystallizes in the trigonal system with the centrosymmetric space group (a = 1189.95(2), c = 7313.27(9) pm, c/a = 6.146; Z = 6; measuring temperature: 100 K). The crystal structure of [La(H2O)9]2[B12H12]3·15 H2O can be characterized by two of each other independent, one into another posed motives of lattice components. The [B12H12]2− anions (d(B–B) = 177–179 pm; d(B–H) = 105–116 pm) are arranged according to the samarium structure, while the La3+ cations are arranged according to the copper structure. The lanthanum cations are coordinated in first sphere by nine oxygen atoms from water molecules in form of a threecapped trigonal prism (d(La–O) = 251–262 pm). A coordinative influence of the [B12H12]2− anions on La3+ has not been determined. Since “zeolitic” water of hydratation is also present, obviously the classical H–Oδ–···H–O‐hydrogen bonds play a significant role in the stabilization of the crystal structure. During the conversion of an aqueous solution of (H3O)2[B12H12] with lanthanum trichloride an anion‐mixed salt with the composition [La(H2O)9](H3O)Cl2[B12H12]·H2O is obtained. The compound crystallizes in the hexagonal system with the non‐centrosymmetric space group (a = 808.84(3), c = 2064.51(8) pm, c/a = 2.552; Z = 2; measuring temperature: 293 K). The crystal structure can be characterized as a layer‐like structure, in which [B12H12]2− anions and H3O+ cations alternate with layers of [La(H2O)9]3+ cations (d(La–O) = 252–260 pm) and Cl anions along [001]. The [B12H12]2− (d(B–B) = 176–179 pm; d(B–H) = 104–113 pm) and Cl anions exhibit no coordinative influence on La3+. Hydrogen bonds are formed between the H3O+ cations and [B12H12]2− anions, also between the water molecules of [La(H2O)9]3+ and Cl anions, which contribute to the stabilization of the crystal structure.  相似文献   

10.
Complex Hydroxides of Chromium: Na9[Cr(OH)6]2(OH)3 · 6 H2O and Na4[Cr(OH)6]X · H2O (X = Cl, (S2)1/2) – Synthesis, Crystal Structure, and Thermal Behaviour Green plate‐like crystals of Na9[Cr(OH)6]2(OH)3 · 6 H2O (triclinic, P1, a = 872.9(1) pm, b = 1142.0(1) pm, c = 1166.0(1) pm, α = 74.27(1)°, β = 87.54(1)°, γ = 70.69(1)°) are obtained upon slow cooling of a hot saturated solution of CrIII in conc. NaOH (50 wt%) at room temperature. In the presence of chloride or disulfide the reaction yields green prismatic crystals of Na4[Cr(OH)6]Cl · H2O (monoclinic, C2/c, a = 1138.8(2) pm, b = 1360.4(1) pm, c = 583.20(7) pm, β = 105.9(1)°) or green elongated plates of Na4[Cr(OH)6](S2)1/2 · H2O (monoclinic, P21/c, a = 580.8(1) pm, b = 1366.5(3) pm, c = 1115.0(2) pm, β = 103.71(2)°), respectively. The latter compounds crystallize in related structures. All compounds can be described as distorted cubic closest packings of the anions and the crystal water molecules with the cations occupying octahedral sites in an ordered way. The thermal decomposition of the compounds was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In all cases the final decomposition product is NaCrO2.  相似文献   

11.
In the presence of N, N′‐dicyclohexylcarbodiimide (DCC), (Bu4N)2[Mo6O18(NAr)] ( 1 ) and (Bu4N)2[Mo6O17(NAr)2] ( 2 ), Ar = o‐CH3C6H4, have been synthesized via the reaction of [α‐Mo8O26]4— with o‐toluidine. If the hydrochloride salt of o‐toluidine was added into the reactive mixture, only the monofunctionalized imido derivative of [Mo6O19]2— was obtained; the bifunctionalized derivative of [Mo6O19]2— was exclusively synthesized in the presence of non‐protonated o‐toluidine. The molecular and crystal structures of the hybrid compounds 1 and 2 were determined by X‐ray single crystal diffraction, and their UV, IR and NMR spectra were compared. Additionally, a possible reaction mechanism was proposed.  相似文献   

12.
通过水热合成技术,一个新颖的基于Zn配合物修饰的Keggin型钴钨酸的有机-无机杂化化合物:[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O已经被合成,化合物通过红外光谱、热重分析和单晶X-射线衍射进行了表征。单晶X-射线衍射的结果显示标题化合物是由一个单支撑的{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2}6-多阴离子,三个[Zn(2,2’-bipy)3]2+阳离子和一个水分子构成。有趣的是[Zn(1)(2,2’-bipy)3]2+阳离子通过氢键连接在一起形成螺旋链。另外标题化合物在空气中是稳定的,并且在室温下显示了强的荧光。  相似文献   

13.
Preparation and Crystal Structures of New Complex Clorides of Lanthanides containing 3, 5‐Dimethylpyridinium Cations: (3, 5‐Dimethylpyridinium)2[LnCl4(H2O)2]Cl (Ln = La, Pr) and (3, 5‐Dimethylpyridinium)3[TbCl6] Crystals of the complex chlorides (3, 5‐dimethylpyridinium)2[LaCl4(H2O)2]Cl ( 1 ), (3, 5‐dimethylpyridinium)2[PrCl4(H2O)2]Cl ( 2 ) and (3, 5‐dimethylpyridinium)3[TbCl6] ( 3 ) have been prepared by reaction of LnCl3 · x H2O (Ln = La, Pr, Tb; x = 6‐7) with 3, 5‐dimethylpyridiniumchloride in ethanol/butanol solution. The crystal structures have been determined from single crystal X‐ray diffraction data. The compounds 1 and 2 are isotypic with each other and crystallize in the triclinic space group P1¯ (Z = 2). The 3, 5‐dimethylpyridinium cations are linked by hydrogen bonds to the anionic part of the structure built up by isolated chloride ions and strings of edge coupled triangulated dodecahedra [LnCl4/2Cl2(H2O)2]. The organic units are arranged forming a “π‐stacking”. 3 cristallizes monoclinically in the space group P21/c (Z = 4). The structure contains octahedral building units [TbCl6]3—. These octahedra are interconnected by the organic cations via hydrogen bonds forming chains parallel to [0 0 1].  相似文献   

14.
Metal Salts of Benzene‐1, 2‐di(sulfonyl)amine. 8. Lamellar Layers Based upon Hydrogen Bonding and π‐Stacking: Crystal Structures of the Complexes [Mg(H2O)6]Z2 and [Be(H2O)4]Z2�2 H2O, where Z is C6H4(SO2)2N The crystal structures of the title complexes (both triclinic, space group P1¯, Z = 1 for M = Mg, Z = 2 for M = Be) have been determined by low‐temperature X‐ray diffraction. They consist of non‐coordinating ortho‐benzenedisulfonimide anions and, respectively, inversion‐symmetric octahedral [Mg(H2O)6]2+ cations or tetrahedral [Be(H2O)4]2+ cations and two non‐coordinating water molecules. In both structures, all O—H hydrogen bond donor groups are used to associate the components into two‐dimensional assemblies comprising an internal polar lamella of metal cations, (SO2)2N groups and water molecules, and hydrophobic peripheral regions consisting of vertically protruding benzo rings. Carbocycles drawn alternatingly from adjacent layers form π‐stacking arrays, whereby the aromatic rings display intercentroid distances in the range 340—370 pm. Several short C—H ⃜O contacts, which may be viewed as weak hydrogen bonds, occur within and between the layers.  相似文献   

15.
On the Crystal Structures of the Transition‐Metal(II) Dodecahydro‐closo‐Dodecaborate Hydrates Cu(H2O)5.5[B12H12]·2.5 H2O and Zn(H2O)6[B12H12]·6 H2O By neutralization of an aqueous solution of the free acid (H3O)2[B12H12] with basic copper(II) carbonate or zinc carbonate, blue lath‐shaped single crystals of the octahydrate Cu[B12H12]·8 H2O (≡ Cu(H2O)5.5[B12H12]·2.5 H2O) and colourless face‐rich single crystals of the dodecahydrate Zn[B12H12]·12 H2O (≡ Zn(H2O)6[B12H12]·6 H2O) could be isolated after isothermic evaporation. Copper(II) dodecahydro‐closo‐dodecaborate octahydrate crystallizes at room temperature in the monoclinic system with the non‐centrosymmetric space group Pm (Cu(H2O)5.5[B12H12]·2.5 H2O: a = 768.23(5), b = 1434.48(9), c = 777.31(5) pm, β = 90.894(6)°; Z = 2), whereas zinc dodecahydro‐closo‐dodecaborate dodecahydrate crystallizes cubic in the likewise non‐centrosymmetric space group F23 (Zn(H2O)6[B12H12]·6 H2O: a = 1637.43(9) pm; Z = 8). The crystal structure of Cu(H2O)5.5[B12H12]·2.5 H2O can be described as a monoclinic distortion variant of the CsCl‐type arrangement. As characteristic feature the formation of isolated [Cu2(H2O)11]4+ units as a condensate of two corner‐linked Jahn‐Teller distorted [Cu(H2O)6]2+ octahedra via an oxygen atom of crystal water can be considered. Since “zeolitic” water of hydratation is also present, obviously both classical H–Oδ?···H–O and non‐classical B–Hδ?···H–O hydrogen bonds play a significant role for the stabilization of the structure. A direct coordinative influence of the quasi‐icosahedral [B12H12]2? anions on the Cu2+ cations has not been determined. The zinc compound Zn(H2O)6[B12H12]·6 H2O crystallizes in a NaTl‐type related structure. Two crystallographically different [Zn(H2O)6]2+ octahedra are present, which only differ in their relative orientation within the packing of the [B12H12]2? anions. The stabilization of the crystal structure takes place mainly via H–Oδ?···H–O hydrogen bonds, since again the hydrogen atoms of the [B12H12]2? anions have no direct coordinative influence on the Zn2+ cations.  相似文献   

16.
From hydrothermal synthesis needle‐shaped crystals of [Ca3(C6H5O7)2(H2O)2] · 2H2O were obtained. The crystal structure was determined by single‐crystal X‐ray experiments and confirmed by powder data (P$\bar{1}$ (no. 2) a = 5.9466(4), b = 10.2247(8), c = 16.6496(13) Å, α = 72.213(7)°, β = 79.718(7)°, γ = 89.791(6)°, V = 947.06(13) Å3, Z = 2, R1 = 0.0426, wR2 = 0.1037). The structure was obtained from pseudo merohedrically polysynthetic twinned crystals using a combined data collection approach and refinement processes. The observed three‐dimensional network is dominated by eightfold coordinated Ca2+ cations linked by citrate anions and hydrogen bonds between two non‐coordinating crystal water molecules and two coordinating water molecules.  相似文献   

17.
Cubic [Ta6Br12(H2O)6][CuBr2X2]·10H2O and triclinic [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl, Br, NO3) cocrystallize in aqueous solutions of [Ta6Br12]2+ in the presence of Cu2+ ions. The crystal structures of [Ta6Br12(H2O)6]Cl2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O ( 1 ) and [Ta6Br12(H2O)6]Br2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O ( 3 )have been solved in the triclinic space group P&1macr; (No. 2). Crystal data: 1 , a = 9.3264(2) Å, b = 9.8272(2) Å, c = 19.0158(4) Å, α = 80.931(1)?, β = 81.772(2)?, γ = 80.691(1)?; 3 , a = 9.3399(2) Å, b = 9.8796(2) Å, c = 19.0494(4) Å; α = 81.037(1)?, β = 81.808(1)?, γ = 80.736(1)?. 1 and 3 consist of two octahedral differently charged cluster entities, [Ta6Br12]2+ in the [Ta6Br12(H2O)6]2+ cation and [Ta6Br12]4+ in trans‐[Ta6Br12(OH)4(H2O)2]. Average bond distances in the [Ta6Br12(H2O)6]2+ cations: 1 , Ta‐Ta, 2.9243 Å; Ta‐Bri , 2.607 Å; Ta‐O, 2.23 Å; 3 , Ta‐Ta, 2.9162 Å; Ta‐Bri , 2.603 Å; Ta‐O, 2.24 Å. Average bond distances in trans‐[Ta6‐Br12(OH)4(H2O)2]: 1 , Ta‐Ta, 3.0133 Å; Ta‐Bri, 2.586 Å; Ta‐O(OH), 2.14 Å; Ta‐O(H2O), 2.258(9) Å; 3 , Ta‐Ta, 3.0113 Å; Ta‐Bri, 2.580 Å; Ta‐O(OH), 2.11 Å; Ta‐O(H2O), 2.23(1) Å. The crystal packing results in short O···O contacts along the c axes. Under the same experimental conditions, [Ta6Cl12]2+ oxidized to [Ta6Cl12]4+ , whereas [Nb6X12]2+ clusters were not affected by the Cu2+ ion.  相似文献   

18.
Li6[TeMo6O24] · 18 H2O is triclinic (space group P1 , a = 1 041.7(1), b = 1 058.6(1), c = 1 070.8(1) pm, α = 61.08(1), β = 60.44(1), γ = 73.95(1)°). Single crystal X-ray structure analysis (Z = 1, 295 K, 317 parameters, 3 973 reflections, Rg = 0.0250) revealed an infinite branched chain of edge-sharing Li coordination polyhedra to be the prominent structural feature. One of the four crystallographically independent Li+ is coordinated octahedrally. The coordination polyhedra of the remaining Li+ are distorted trigonal bipyramids. Only three unique oxygen atoms (O(9), O(10), O(12)) of the centrosymmetric [TeMo6O24]6? anion are bound to Li+. The further positions in the coordination spheres of the Li+ are occupied by water molecules. Intermolecular hydrogen bonds involve mainly oxygen atoms of the [TeMo6O24]6? anion as nearly equivalent proton acceptors without regard to their different bonding modes to Te and Mo, respectively. Li6[TeMo6O24] · Te(OH)6 · 18 H2O crystallizes monoclinically in space group P21/n with Z = 4, a = 994.1(3), b = 2 344.8(10), c = 1 764.9(4) pm, and β = 91.36(4)°. Single crystal structure analysis with least squares refinement of 627 parameters (5 900 reflections, 295 K) converged to Rg = 0.0324. There are six unique Li+ cations. The coordination polyhedra of Li(1), Li(2), Li(3), and Li(4) are linked by common edges to yield an eight membered centrosymmetric strand. The coordination polyhedra of the remaining two Li+ sites (Li(5), Li(6)) are connected to a dimeric unit via a common corner. All oxygen atoms of the Te(OH)6 molecule are involved in the coordination of Li+. However, only three oxygen atoms (O(13), O(18), O(23)) of the [TeMo6O24]6? anion which lacks crystallographic symmetry are involved in the coordination of Li+. The oxygen atoms of the anion act as proton acceptors in hydrogen bonds of predominantly medium strength. Te(OH)6 molecules and [TeMo6O24]6? anions connected by strong hydrogen bonds form an infinite chain.  相似文献   

19.
Synthesis, Crystal Structure, and Thermal Decomposition of Mg(H2O)6[B12H12] · 6 H2O By reaction of an aqueous solution of the free acid (H3O)2[B12H12] with MgCO3 and subsequent isothermic evaporation of the resulting solution to dryness, colourless, bead‐shaped single crystals of the dodecahydrate of magnesium dodecahydro closo‐dodecaborate Mg(H2O)6[B12H12] · 6 H2O (cubic, F4132; a = 1643.21(9) pm, Z = 8) emerge. The crystal structure is best described as a NaTl‐type arrangement in which the centers of gravity of the quasi‐icosahedral [B12H12]2— anions (d(B—B) = 178—180 pm, d(B—H) = 109 pm) occupy the positions of Tl while the Mg2+ cations occupy the Na+ positions. A direct coordinative influence of the [B12H12]2— units at the Mg2+ cations is however not noticeable. The latter are octahedrally coordinated by six water molecules forming isolated hexaaqua complex cations [Mg(H2O)6]2+ (d(Mg—O) = 206 pm, 6×). In addition, six “zeolitic” water molecules are located in the crystal structure for the formation of a strong O—Hδ+···δ—O‐hydrogen bridge‐bonding system. The evidence of weak B—Hδ—···δ+H—O‐hydrogen bonds between water molecules and anionic [B12H12]2— clusters is also considered. Investigations on the dodecahydrate Mg[B12H12] · 12 H2O (≡ Mg(H2O)6[B12H12] · 6 H2O) by DTA/TG measurements showed that its dehydration takes place in two steps within a temperature range of 71 and 76 °C as well as at 202 °C, respectively. Thermal treatment eventually leads to the anhydrous magnesium dodecahydro closo‐dodecaborate Mg[B12H12].  相似文献   

20.
A series of lanthanide coordination polymers, [LnIII(mal)(ox)0.5(H2O)2]·2H2O (Ln = Pr ( 1 ), Nd ( 2 ), and La ( 3 ); H2mal= maleic acid; H2ox = oxalic acid), were synthesized firstly by the reaction of LnIII nitrate salts with maleic anhydrid and oxalic acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. X‐ray diffraction analyses reveal that they are crystallized in orthorhombic space group Fddd. Lanthanide metal center atom (Ln) and its corresponding centrosymmtric atom link through two chelating/bridging bidentate carboxyl groups of maleic acid ligands to form an infinite inorganic rod‐shaped building unit. These rod‐shaped building units were linked to each other through the carbon atoms of the maleate anions on the [110] plane to form lanthanide‐maleic acid layers. The oxalic acid pillared lanthanide‐maleic acid layers with intersected channels by free water molecules consist of a 3D framework structure. The thermogravimetric analyses of 1 – 3 were discussed in detail. The courses of the thermal decomposition of complexes are similar.  相似文献   

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