Interactions of thiamine monophosphate (TMP) with one- and two-dimensional polymeric halogenomercurate anions. Crystal structures of (TMP)(Hg2Br5)center dot 0.5H(2)O and (TMP)(2)(Hg3I8)

An investigation into the interactions between thiamine monophosphate (TMP) and anions has resulted in the preparation and X-ray characterization of the compounds (TMP)(Hg2Br5).0.5H(2)O (1) and (TMP)(2)(Hg3I8) (2). In each compound the TMP molecule exists as a monovalent cation in the usual F conformation. The halogenomercurate anions occur in two-dimensional (2-D) network in 1 or one-dimensional (1-D) chain in 2. In both 1 and 2, the structures consist of alternating cationic sheets of the hydrogen-bonded TMP molecules and anionic sheets of the polymeric halogenomercurate anions. The TMP molecule binds to the polymeric anions through the characteristic 'anion bridge I', C(2)-H..X...pyrimidinium (X = Br in 1 and 1 in 2), and electrostatic interactions between electropositive S(1) and halogen atoms. The 'anion bridge II' of the type N(4'1)-H...X...thiazolium (X = phosphate group) plays a role in stabilizing the molecular conformation. The biological implication of the host-guest-like complexation between TMP and polymeric anions is discussed.

Synthesis and crystal structure of cyclopentylindene rare earth complex (C5H9C9H6)(3)SMCl-Li+ (THF)(4)

Rare earth complex (C5H9C9H6)(3)SmCl-Li+ (THF)(4)( I ) was synthesized by reacting anhydrous SmCl3 with two equivalents of C5H9C9H6Li. From mix-solvent of THF and hexane, red color single crystals were obtained. The crystal belongs to a cubic system, space group P2(1)3 with unit cell parameters a= b=c= 1. 754 0(2) nm, alpha=beta=gamma=90degrees, V=5. 396 4(11) nm(3), Z = 4. The ten-coordinated samarium atom is bonded to three cyclopentylindenyl rings and a chlorine atom to form the anionic part of the title complex, ring centroids and the chlorine atom form a tortured tetrahedron around samarium. In the cationic part, lithium atom coordinates to four oxygen atoms of THF molecules to form a normal tetrahedron. The Sm-C(within the same ring) distance varies from 0. 268 to 0. 299 nm.

Solvent-dependent formation of di- and trinuclear rhodiurn and iridium complexes bridged by N,N '-donor ligands

Reactions of Rh and Ir hydrido complexes. [Rh(H)(2)(PPh3)(2)(solv)(EtOH)]ClO4 (solv = Me2CO, 1a; EtOH, 1b) and [Ir(H)(2)(PPh3)(2)(Me2CO)(2)]BF4 (2), with various N,N'-donor bridging ligands, such as pyrazine (pyz), 4,4'-trimethylenedipyridine (tmdp) and di(4-pyridyl) disulfide (dpds), in some solvents were examined, and their reaction products were characterized by X-ray crystal structure analysis. IR, H-1 NMR and UV-vis spectra. Rh hydrido complexes, la or 1b, formed a dinuclear Rh complex, [Rh-2(PPh3)(2) {(eta(6)-C6H5PPh2}(2)] (ClO4)(2).6CH(2)Cl(2) (3.6CH(2)Cl(2)), in dichloromethane with a reductive elimination of hydrogen. The reactions of 1a or 1b with the pyz ligand in dichloromethane and tetrahydrofuran gave triangular Rh-3 complexes, [Rh-3(PPh3)(6)(pyz)(3)](ClO4)(3).CH2Cl2 (5.CH2Cl2) and [Rh-3(PPh3)(6)(pyz)(3)](ClO4)(3).EtOH (5.EtOH), respectively, in contrast to the formation of a dinuclear Rh hydrido complex, [Rh-2(H)(4)(PPh3)(4)(Me2CO)(2)(pyz)](ClO4)(2).EtOH A-EtOH). in acetone. The reactions of la or 1b with the tmdp ligand in dichloromethane and 3-methyl-2-butanone also afforded dinuclear Rh complexes, [Rh-2(PPh3)(4)(tmdp)(2)](ClO4)(2) (6) and [Rh-2(PPh3)(4)(tmdp)(2)](ClO4)(2).4MeCOCHMe(2) (6.4MeCOCHMe(2)), respectively. On the other hand, Ir hydrido complex 2 reacted with pyz and dpds ligands in dichloromethane to afford dinuclear Ir complexes, [Ir-2(H)(4)(PPh3)(4)(Me2CO)(2)(pyz)]- (BF4)(2).3CH(2)Cl(2) (7.3CH(2)Cl(2)) and [Ir-2(H)(4)(PPh3)(4)(dpds)(2)](BF4)(2).3CH(2)Cl(2).H2O (8.3CH(2)Cl(2).H2O), respectively, without any reductive elimination of hydrogen. Based on structural studies in solution and in the solid state. it was demonstrated that various Rh and Ir complexes were selectively produced depending on the choice of solvents and N,N'-donor bridging ligands.

Synthesis and characterization of tris(cyclopentylcyclopentadienyl)lanthanide complexes (C5H9C5H4)(3)NdBrLi(THF)(3) and (C5H9C5H4)(3)SmTHF

(C5H9C5H4)(3)NdBrLi(THF)(4)(1)(C5H9=cyclopentyl) was obtained from the reaction of NdCl3 with C5H9C5H4Na and LiBr (Nd:Na:Li=1:2:1 molar ratio) in THE X-ray crystallography showed that the ten-coordinated neodymium atom is bonded to three cyclopentylcyclopentadienyl(eta(5)) rings and a single bromine atom bridging a lithium which is bonded to three THF molecules. Complex 1 is triclinic, P1 space group with unit dimensions of a= 12.048(2), b= 13.498(3), c= 13.831(3)Angstrom, a = 104.16(3), beta = 104.07(3), gamma =95.96(3)degrees, V=2083.3(7)Angstrom(3), Z=2, D-c=1.35Mg/m(3) and F(000)=874. (C5H9C5H4)(3)SmTHF (2) was synthesized by reaction of anhydrous SmCl3 with C5H9C5H4Na at a molar ratio of 1:3. The structure was determined by X-ray crystallography. The ten-coordinated samarium atom is bonded to three cycloperrtylcyclopentadienyl rings and one oxygen of THF molecule to form a pseudo-tetrahedron. Complex 2 is orthorhombic, Fdd2 space group with unit cell dimensions of a =28.175(5)Angstrom, b =46.24(2) Angstrom, c =9.167(4) Angstrom(3), V=11943(8)Angstrom(3), Z= 16, D-c = 1.38Mg/m(3) and F(000)=5136.

Hydrothermal synthesis and structural characterization of a novel organic-inorganic hybrid compound {[Cu(2, 2 '-bpy)(2)](2)-Mo8O26}

A novel organic-inorganic hybrid compound {[Cu (2, 2'-bpy)(2)](2)Mo8O26} has been hydrothermally Synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group, Pna2(1), with a=2.4164 (5), b=1.8281 (4), c=1.1877 (2) nm, V=5.247(2) nm(3), Z=4, and final R-1=0.0331, wR(2)=0.0727. The structure consists of discrete {[Cu(2,2'-bpy)(2)](2)Mo8O26} clusters, constructed from a beta -octamolybdate subunit[Mo8O26](4-) covalently bonded to two [Cu(2,2'-bpy)(2)](2+) coordination complex cations via bridging oxo groups. In addition, the spectroscopic properties and thermal behavior of this compound have been investigated by spectroscopic techniques (UV-vis, IR, Raman and EPR spectra) and TG analysis.

Gas transport properties of a series of cardo polyarylethers

Gas transport of H-2, CO2, O-2, N-2, and CH4 in a series of cardo polyarylethers were examined over a temperature range of 30 similar to 100 degreesC. These polymers include three poly(aryletherketone)s, two poly(arylethersulfone)s, and one poly(aryletherketoneketone). It was found that the large length/diameter ratio of the polymer repeat unit for cardo polyaryletherketoneketone (PEKK-C) and strong intermolecular interaction in hydrogen-bonded polyarylethersulfone (PES-H) and hydrogen-bonded polyaryletherketone (PEK-H) resulted in a considerable increase in gas permselectivity. Alkyl-substituted polyaryletherketone (PEK-A), bearing a pendant bulky propyl group on the cardo ring, simultaneously exhibited 62.5% higher H-2 permeability and 59.8% higher H-2/N-2 permselectivity than unmodified poly(aryletherketone) (PEK-C). The causes of the trend were interpreted in terms of chain packing density, segmental motion ability, steric factor, and intermolecular interaction of polymers, together with gas kinetic diameter and critical temperature data.

A chromic molybdenum phosphate with a tunnel structure: hydrothermal synthesis and structure of (NH3CH2CH2NH3)(2) center dot (NH3CH2CH2NH2)(3)center dot[NaCr2Mo12O30(PO4)(HPO4)(4)(H2PO4)(3)]center dot 6H(2)O

A chromic molybdenum phosphate, (NH3CH2CH2NH3)(2).(NH3CH2CH2NH2)(3).[NaCr2Mo12O30(PO4)(HPO4)(3)]. 6H(2)O, involving molybdenum present in V oxidation, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction and IR spectrum. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a = 12.067(2), b = 14.677(3), c = 21.290(2) Angstrom, alpha = 80.940(10)degrees, beta = 82.960(10)degrees, gamma = 76.61(2)degrees. The structure of the title compound may be considered to be two [Mo6O15(HPO4)(H2PO4)(3)](5-) units bonded to a chromic atom, although several P-O groups are not protonated on account of coordination with a Na+ cation. The one-dimensional tunnels were formed in the solid of the title compound. (C) 2000 Elsevier Science B.V. All rights reserved.

Metal ion and anion coordination in the thiamine-[Pt-II(NO2)(4)](2-) system. Structures of a metal complex, Pt(thiamine)(NO2)(3), and two salts, (H-thiamine)[Pt(NO2)(4)]center dot 2H(2)O and (thiamine monophosphate)(2)[Pt(NO2)(4)]center dot 2H(2)O

Reaction of thiamine or thiamine monophosphate (TMP) with K2Pt(NO2)(4) afforded a metal complex, Pt(thiamine)(NO2)(3) (1), and two salt-type compounds, (H-thiamine)[Pt(NO2)(4)]. 2H(2)O (2) and (TMP)(2)[Pt(NO2)(4)]. 2H(2)O (3), which were structurally characterized by X-ray diffraction. In 1, the square-planar Pt2+ ion is coordinated to the pyrimidine N(1'), a usual metal-binding site, and three NO2- groups. The thiamine molecule exists as a monovalent cation in 1 and a divalent cation in 2 while the TMP molecule is a monovalent cation in 3. In each compound, thiamine or TMP adopts the usual F conformation and forms two types of host-guest-like interactions with anions, which are of the bridging forms, C(2)-H . . . anion . . . pyrimidine-ring and N(4'1)-H(...)anion(...)thiazolium-ring. In 3, there is an additional anion-bridging interaction between the pyrimidine and thiazolium rings of TMP, being of the form C(6')-H . . . anion . . . thiazolium-ring. The salts 2 and 3 show similar hydrogen-bonded cyclic dimers of thiamine or TMP between which the anions are held. Results are compared with those of the other thiamine-platinum complexes. (C) 2001 Elsevier Science B.V. All rights reserved.

Influence of temperature on lattice spacings of melt-crystallized poly(iminosebacoyl iminodecamethylene)

The variation of lattice spacings of poly(iminosebacoyl iminodecamethylene) (nylon-10,10) with temperature was studied by wide-angle X-ray diffraction (WAXD) during both heating and cooling processes, which demonstrates a gradual and continuous transition with temperature. However, the crystal melts before the two peaks merge completely. Both WAXD and differential scanning calorimetry show that crystallization from molten sample results directly in the triclinic form. Additionally, this transition is thermodynamically reversible. Comparison of this transition with that of nylon-6,6, suggests that no hydrogen-bonded network is formed during or after the transition. We prefer to attribute this transition to asymmetrical thermal expansion in the nylon-10,10 crystals rather than to a true first-order phase transition. (C) 2001 Society of Chemical Industry.

The research of cellulose derivatives as chiral stationary phases and high performance liquid chromatography with polarimeter as on-line detector

Three cellulose derivatives were synthesized and used as chiral stationary phases based on silica gel. The effects of adsorbances on the column numbers and stabilities have been investigated. These stationary phases exhibited high chiral recognition for various racemates. At the same time, the on-line curves of polarimeter were obtained by high performance liquid chromatography with polarimeter as on-line detector.

Morphology and structure of micro-fibrillar crystal of nylon 10 10

The nanoscale and microscale fibrillar crystals of nylon 10 10 were obtained by atomizing the very dilute formic acid solution. The length-diameter ratio of these fibrillar crystals increases as the concentration of the atomizing solution increases. Electron diffraction (ED) analysis showed that the hydrogen-bonded sheet in these solution-grown fibrillar crystals was imperfect and had a lower order. Both electron diffraction and characteristic morphology show that melt-crystallized fibrillar crystals always possess perfect packing order and stable structure. A rather perfect ED pattern of the triclinic form of nylon 10 10 along the [001] zone was obtained by tilting the specimen 41 degrees along the elongated direction of the crystal. Fibrillar crystals from bulk have a great tendency to aggregate with parallel packing to form crystal clusters, which look like shish kebabs in morphology. Spherulite is observed occasionally in the domains with very rich sample. (C) 2001 Elsevier Science Ltd. All rights reserved.

A manganese molybdenum phosphate with a tunnel: hydrothermal synthesis, structure and catalytic properties of (NH3CH2CH2NH3)(10-)H3O)(3)(H5O2)Na-2[MnMo12O24(OH)(6)(PO4)(4)(PO3OH)(4)]-[MnMo12O24(OH)(6)(PO4)(6)(PO3OH)(2)] center dot 9H(2)O

A manganese molybdenum phosphate, (NH3CH2CH2NH3)(10)(H3O)(3)(H5O)Na-2[MnMo12O24(OH)(6) (PO4)(4)(PO3OH)(4)][MnMo12O24 (OH)(6)(PO4)(6)(PO3OH)(2)]. 9H(2)O, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. The structure of this compound may be considered to be two [Mo6O12(OH)(3)(PO4)(2)(HPO4)(2)](7-) units bonded together by a manganese atom, although several P-O groups are not protonated on account of coordination to a Na+ cation. One-dimensional tunnels were formed in the solid. A probe reaction of the oxidation of acetaldehyde with H2O2 using this compound as catalyst was carried out in a liquid-solid system, showing that the manganese molybdenum phosphate has high catalytic activity in the reaction.

Influence of interface on radiation effects of crystalline polymer - radiation effects on polyamide-1010 containing BMI

Aimed at saving the radiation dose required to crosslinking the polyamid-1010, BMI/PA1010 systems containing different amounts of difunctional crosslinking agent N,N'-bis-maleimide-4,4'-biphenyl methane (BMI) were prepared and the structure changes at the crystallographic and supermolecular levels before and after irradiation were studied by using WAXD, SAXS, and DSC techniques. It was found that by incorporation of BMI the microcrystal size L-100 is lowered due to the formation of hydrogen bond between the carbonyl oxygen of BMI and the amide hydrogen of PA1010 in the hydrogen bonded plane, and the overall crystallinity W-c is also decreased. The presence of BMI causes the crystal lamella thickness d(c) to decrease and greatly thickens the transition zone d(tr) between the crystalline and amorphous regions. As for the irradiated specimen, the maximum increments in the L-100 and W-c against dose curves decrease with BMI content, and the interception point D-i, at which the L-100 and W-c curves intercept their respective horizontal line of L-100/L-100(0) and W-c/W-c(0)=1, shift to lower dose with an increase in BMI concentration. In addition. the mechanism of the radiation chemical reactions in the three different phases under the action of BMI are discussed with special focus on the interface region. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.

A nickel molybdenum phosphate with tunnel: Hydrothermal synthesis and structure of (NH3CH2CH2NH3)(4)center dot(NH3CH2CH2NH2)center dot Na center dot[Ni2Mo12O30(PO4)(HPO4)(4)(H2PO4)(3)]center dot 6H(2)O

A nickel molybdenum phosphate, (NH3CH2CH2NH3)(4).(NH3CH2CH2NH2). Na .[Ni2Mo12O30(PO4)(HPO4)(4)(H2PO4)(3)]. 6H(2)O, invoicing molybdenum present in V oxidation, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a = 12,011(2), b = 14,612(3), c = 21.252(4) Angstrom, alpha = 80.54(2)degrees, beta = 83.10(2)degrees, gamma = 76.29(2)degrees, V = 3561.4(12) Angstrom(3), Z = 2, lambda(MoK alpha) = 0.71073 Angstrom (R(F) = 0.0529 for 9880 reflections), Data mere collected on a Siemens P4 diffractometer at 20 degrees C in the range of 1.75 degrees < theta < 23.02 degrees using the omega-scan technique. The structure was solved by direct methods using the program SHELXTL-93 and refined with the method of fun-matrix least-squares on F-2. The structure of the title compound may be considered to be two [Mo6O15(HPO4)(H2PO4)(3)](5-) units bonded together with a nickel atom, although several P-O groups are not protonated on account of coordination with a Na+ cation, The one-dimensional tunnels were formed in the solid of the title compound. A probe reaction of the oxidation of acetaldehyde with H2O2 using the title compound as catalyst was carried out in a liquid- solid system, showing that the title compound had high catalytic activity in the reaction, (C) 1999 Academic Press.

Metal-oxo cluster-supported transition metal complexes: hydrothermal synthesis and characterization of [{M(phen)(2)}(2)(Mo8O26)] (M = Ni or Co)

Two new metal-ore supported transition metal complexes, E{M(phen)(2)}(2)(Mo8O26) (M = Ni or CO; phen = 1,10-phenanthroline) are synthesized by a hydrothermal method and characterized by X-ray crystallography, showing that the octamolybdate possesses a novel unprecedented structure and that [M(phen)(2)](2+) units are covalently bonded to the [Mo8O26](4-) cluster.