Channel-selective independent sorption and collection of hydrophilic and hydrophobic molecules by Cs2[Cr3O(OOCC2H5)6(H2O)3]2[alpha-SiW12O40] ionic crystal

An ionic crystal of Cs2[Cr3O(OOCC2H5)6(H2O)3]2[alpha-SiW12O40].4H2O 1a with hydrophilic and hydrophobic channels has been designed and successfully synthesized. The guest-free phase 1b sorbs dichloromethane and water in the hydrophobic and hydrophilic channels, respectively. The rate and equilibrium amount of the dichloromethane sorption into the hydrophobic channel and those of water into the hydrophilic channel were independent of each other. The sorption properties can be applied to the channel-selective sorption and collection of hydrophobic (dichloromethane) and hydrophilic (water) molecules from the mixture.     

Control of structures and sorption properties of ionic crystals of A2[Cr3O(OOCC2H5)6(H2O)3]2[alpha-SiW12O40] (A = Na, K, Rb, NH4, Cs, TMA)

The complexation of Keggin-type polyoxometalate [alpha-SiW 12O 40] (4-), macrocation [Cr 3O(OOCC 2H 5) 6(H 2O) 3] (+), and monovalent cation A (+) forms ionic crystals of A 2[Cr 3O(OOCC 2H 5) 6(H 2O) 3] 2[alpha-SiW 12O 40]. nH 2O [A = Na ( 1a), K ( 2a), Rb ( 3a), NH 4 ( 4a), Cs ( 5a), and tetramethylammonium (TMA) ( 6a)]. Single crystal (1a- 4a and 6a) and powder (5a) X-ray analyses have shown that the ionic crystals possess 2D layers of polyoxometalates and macrocations. Compounds 2a- 5a had almost the same structure, while the layers in 1a and 6a stack in different ways. The structures and sorption properties of 2b- 5b are investigated in more detail. The interlayer distances of guest free phases 2b- 5b increase with the increase in the ionic radii of the monovalent cations, which reside between the layers. Compounds 2b- 5b possess hydrophobic and hydrophilic channels, which exist between the layers and through the layers, respectively. The volumes of the hydrophobic channels increase in the order of 2b < 3b approximately 4b < 5b, and those of the hydrophilic channels increase in the order of 2b < or = 3b < or = 4b < 5b. Single-crystal X-ray structure analyses of 2a- 4a have shown that the water of crystallization resides in the hydrophilic channel. It is probable that the water of crystallization in 5a resides in the hydrophilic channel in the same manner as those in 2a- 4a since 2a- 5a have almost the same structure. The water vapor sorption profiles of 2b- 5b are approximately reproduced by a linear driving force model. Therefore, water molecules sorbed in 2b- 5b probably reside in the hydrophilic channel. The n-propanol sorption profiles are reproduced by the summation of the linear driving force model, showing that two independent barriers exist in the n-propanol sorption. The in situ IR spectra of n-propanol sorbed showed the presence of two n-propanol species. These data show that n-propanol is sorbed into both hydrophilic and hydrophobic channels. Compound 5b sorbs halocarbons in the hydrophobic channel, while 2b- 4b exclude them.     

Unique guest-inclusion properties of a breathing ionic crystal of K3[Cr3O(OOCH)6(H2O)3][alpha-SiW12O40].16 H2O

A microstructured ionic crystal, K(3)[Cr(3)O(OOCH)(6)(H(2)O)(3)][alpha-SiW(12)O(40)].16 H(2)O (1) was synthesized by the complexation of the Keggin-type polyoxometalate of [alpha-SiW(12)O(40)](4-) with a macrocation of [Cr(3)O(OOCH)(6)(H(2)O)(3)](+). Compound 1 possessed a straight channel, with an opening of approximately 0.5x0.8 nm, which contained the water of crystallization. The use of the macrocation with large size (0.7 nm) and small charge (+1) reduced the anion-cation interaction and was essential for the channel formation. The molecular structures of the polyoxometalate and the macrocation in 1 were retained under vacuum at 473 K. Analogues of 1 were synthesized with [alpha-PVW(11)O(40)](4-) or [Fe(3)O(OOCH)(6)(H(2)O)(3)](+). The water of crystallization in 1 was removed under vacuum at room temperature to form the closely packed guest-free phase 2. Compound 2 reversibly and repeatedly included water and polar organic molecules with two carbon atoms or less. Guest inclusion was highly selective and a difference of even one methylene group in the organic guest molecule was discriminated by the host. Polar organic molecules with longer methylene chains and nonpolar molecules such as dinitrogen and methane were completely excluded. The guest-inclusion properties could be explained by the ion-dipole interaction between the host and the guest, which is proportional to the dipole moment of the guest molecule and inversely proportional to the ion-dipole (host-guest) distance. Thus, small polar molecules were selectively absorbed. These distinctive guest-inclusion properties were successfully applied to the oxidation of methanol from a mixture of C(1) and C(2) alcohols. These results show unique guest inclusion and catalysis by rationally designed ionic crystals.     

Zeotype ionic crystal of Cs5[Cr3O(OOCH)6(H2O)3][alpha-CoW12O40].7.5H2O with shape-selective adsorption of water

A polyoxometalate-macrocation ionic crystal of Cs5[Cr3O(OOCH)6(H2O)3][alpha-CoW12O40].7.5H2O (1a) was synthesized by the complexion of an inorganic metal-oxide cluster of [alpha-CoW12O40]6- and a macrocation of [Cr3O(OOCH)6(H2O)3]+. About 50% of the water of crystallization in 1a was desorbed by the evacuation to form phase 1b, and the crystallinity and crystal structure was essentially maintained by the transformation. 1b adsorbed water into the solid bulk but excluded larger alcohols. 1b was easily reusable for the separation of only water in the azeotropic mixture of ethanol and water.     

K3[Cr3O(OOCH)6(H2O)3][α-GeW12O40]·17H2O 的合成、结构及特性研究

研究了多金属氧酸盐分子基化合物K3[Cr3O(OOCH)6(H2O)3][α-GeW12O40]·17H2O的合成、晶体结构及其结晶水可逆脱附和吸附性能.该化合物属于单斜晶系,C2/m空间群,α=2.738 3(6)nm,b=1.58 3 0(3)nm,c=1.730 4(4)nm,β=102.43(3)°,V=7.325(3)nm3,Z=4,R1(wR2)=0.067 8(0.171 9).该晶体具有孔道结构,孔道内的结晶水能够可逆的脱附和吸附,而晶体结构随之恢复,因此具有分子筛的特性.     

Syntheses,Crystal Structures,and Properties of the Isotypic Pair [Cr(H2O)6]2[B12H12]3·15H2O and [In(H2O)6]2[B12H12]3·15H2O

Single crystals of [Cr(H₂O)₆]₂[B₁₂H₁₂]₃ · 15H₂O and [In(H₂O)₆]₂[B₁₂H₁₂]₃ · 15H₂O were obtained by reactions of aqueous solutions of the acid (H₃O)₂[B₁₂H₁₂] with chromium(III) hydroxide and indium metal shot, respectively. The title compounds crystallize isotypically in the trigonal system with space group R$\bar{3}$ c (a = 1157.62(3), c = 6730.48(9) pm for the chromium, a = 1171.71(3), c = 6740.04(9) pm for the indium compound, Z = 6). The arrangement of the quasi‐icosahedral [B₁₂H₁₂]^2– dianions can be considered as stacking of two times nine layers with the sequence …ABCCABBCA… and the metal trications arrange in a cubic closest packed …abc… stacking sequence. The metal trications are octahedrally coordinated by six water molecules of hydration, while another fifteen H₂O molecules fill up the structures as zeolitic crystal water or second‐sphere hydrating species. Between these free and the metal‐bonded water molecules, bridging hydrogen bonds are found. Furthermore, there is also evidence of hydrogen bonding between the anionic [B₁₂H₁₂]^2– clusters and the free zeolitic water molecules according to B–H^δ– ··· ^δ+H–O interactions. Vibrational spectroscopy studies prove the presence of these hydrogen bonds and also show slight distortions of the dodecahydro‐closo‐dodecaborate anions from their ideal icosahedral symmetry (I_h). Thermal decomposition studies for the example of [Cr(H₂O)₆]₂[B₁₂H₁₂]₃ · 15H₂O gave no hints for just a simple multi‐stepwise dehydration process.     

Hybrid Tungstocuprate [Cu(2,2'-bpy)3]2H4[CuW12O40]·6H2O Based on Keggin Polyoxoanion [CuW12O40]6-with CuⅡas Heteroatom

A novel hybrid tungstocuprate(Ⅱ) [Cu(2,2'-bpy)3]2H4[CuW12O40]·6H2O(2,2'-bpy=2,2'-bipyridine) was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [CuW12O40]6- and a pair of chiral complex cations [Cu(2,2'-bpy)3] together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [Cu(2,2'-bpy)3] via multiple C-H…O hydrogen bonds resulting in a dimer.     

Die IR-Spektren von [Cr(O2)2(NH3)3] und K3[Cr(O2)2(CN)3]

The infrared spectra of the title compounds are reported and discussed. The influence of the peroxide groups on the bond properties of the other ligands and some characteristics of the metal—peroxide interactions are analyzed.     

K3Na5(H2NCH2CH2NH3)2{(VO)12O6[B3O6(OH)]6}(H2O)•12H2O的合成与晶体结构

利用水热合成技术成功制备出一种新型多钒硼氧化合物， 用X射线单晶衍射分析技术对其晶体结构和分子结构进行了确定。结果表明在该化合物中多钒硼氧阴离子具有一个新颖的三明治结构。上下两个结构单元都是由六个VO₅四角锥交替地通过顺式和反式共边的方式连接起来构成的一个钒氧三角形结构。中间的结构单元是由BO₃平面三角形和BO₄四面体以共角的方式相互连接形成的一个折叠型的B₁₈O₃₆(OH)₆环。三明治结构中层与层之间通过桥氧相连。一个水分子处于它的核心位置上，与每个VO₅四角锥中的钒原子都保持几乎相等的距离。该化合物及其晶体中存在着丰富的化学结构和成键信息，同时也有作为氧化还原反应催化剂的潜能。     

VO(H2O)5]H[PMo12O40]-catalyzed nitration of alkanes with nitric acid

[VO(H2O)5]H[PMo12O40], which contains vanadyl counter cations and PMo12O40(3-), can act as a catalyst for the nitration of various alkanes including alkylbenzenes using nitric acid as a nitrating agent in acetic acid at 356 K.     

A polyoxometallate-templated coordination polymer: synthesis and crystal structure of [Cu3(4,4'-bipy)5(MeCN)2]PW12O(40).2C6H5CN

The spherical phosphotungstate ion, PW12O40(3-), has been used as a non-coordinating anionic template for the construction of a novel, three-dimensional Cu(I) coordination polymer.     

K4H2[PMo9V3O40]·10H2O的合成及其晶体结构

采用低温技术,用X射线单晶衍射法测定了标题化合物的结构。晶体属P4/mnc空间群,=12.515(3),c=17.636(7)A,Z=2.用788个独立可观测反射精修所有结构参数得R=0.061.钼钒磷杂多酸阴离子中,PO4四面体是无序的,P-O键长1.54A.M(Mo,V)是6配位,M-O键长1.62-2.48A,K是7配位,K-O键长2.84-3.10A。     

一种新颖的六帽Keggin型钼钒砷酸盐——(H3O)3[AsMo12O40(VO)6]·6H2O的水热合成和晶体结构

近年来,含有Keggin结构的杂多酸以其优异的结构可修饰性及其在催化、功能材料和医药等方面的潜在应用而引起人们广泛的研究兴趣.在这一领域中,众多过渡金属取代的Keggin型杂多化合物,尤其是含有钒和铝的多金属氧酸盐由于其独特的电磁特性及结构特点而倍受关注.但迄今为止,只有少数带帽Keggin型结构的杂多阴离子被报道.这些Keggin阴离子通常具有低的V/Mo.     

Cis-trioxa-tris-β-homobenzene as tridentate ligand : X-ray crystal structure analyses of [Li(C6H6O3)2 PF6] and [Ca(C6H6O3)3H2O(ClO4)2]

In the title complexes the cis-benzenetrioxide acts as tridentate ligand, allowing for octahedral and unusual tetracapped trigonal prismatic coordination (TECTP).     

Double complexes [Co(NH3)5(H2O)]2[Zr3F18]·6H2O and [Co(NH3)6]2[Zr3F18]·6H2O

The structures of orthorhombic bis[pentaammineaquacobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Ibam), [Co(NH₃)₅(H₂O)]₂[Zr₃F₁₈]·6H₂O, (I), and bis[hexaamminecobalt(III)] tetra‐μ₂‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Pnna), [Co(NH₃)₆]₂[Zr₃F₁₈]·6H₂O, (II), consist of complex [Co(NH₃)_x(H₂O)_y]³⁺ cations with either m [in (I)] or and 2 [in (II)] symmetry, [Zr₃F₁₈]⁶⁻ anionic chains located on sites with 222 [in (I)] or 2 [in (II)] symmetry, and water molecules.