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1.
The triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) copolymers, Pluronics (L64, P65, and P123), form liquid crystalline (LC) mesophases with transition metal nitrate salts (TMS), [M(H(2)O)(n)](NO(3))(2), in the presence and absence of free water in the media. In this assembly process, M-OH(2) plays an important role as observed in a TMS:C(n)EO(m) (C(n)EO(m) is oligo(ethylene oxide) nonionic surfactants) system. The structure of the LC mesophases and interactions of the metal ion-nitrate ion and metal ion-Pluronic were investigated using microscopy (POM), diffraction (XRD), and spectroscopy (FTIR and micro-Raman) techniques. The TMS:L64 system requires a shear force for mesophase ordering to be observed using X-ray diffraction. However, TMS:P65 and TMS:P123 form well structured LC mesophases. Depending on the salt/Pluronic mole ratio, hexagonal LC mesophases are observed in the TMS:P65 systems and cubic and tetragonal LC mesophases in the TMS:P123 systems. The LC mesophase in the water/salt/Pluronic system is sensitive to the concentration of free (H(2)O) and coordinated water (M-OH(2)) molecules and demonstrates structural changes. As the free water is evaporated from the H(2)O:TMS:Pluronic LC mesophase (ternary mixture), the nitrate ion remains free in the media. However, complete evaporation of the free water molecules enforces the coordination of the nitrate ion to the metal ion in all TMS:Pluronic systems. 相似文献
2.
Phase transitions of polycrystalline [Fe(H2O)6](ClO4)3 and [Cr(H2O)6](ClO4)3 studied by DSC 总被引:1,自引:0,他引:1
Mikuli E. Grad B. Zaremba K. Wróbel S. 《Journal of Thermal Analysis and Calorimetry》2004,76(3):719-726
The effects of heat treatment on soymilk protein denaturation were studied by differential scanning calorimetry (DSC) and
electrophoresis. Transition behavior of soymilk was studied by DSC. Three endotherms were found in DSC heating curves; the
transition observed at around 70°C is attributed to the denaturation of 7S (b-conglycinin) and the transition at around 90°C
is to 11S (glycinin). The denaturation temperature increased with the increasing soymilk protein content. The change of electrophoretic
patterns after heat treatments indicated that soy proteins were dissociated into subunits, some of which coalesced. When the
heating temperature is below their denaturation temperature, the protein fractions cannot completely be denatured even after
heat exposure for extended periods of time.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Bezombes JP Hitchcock PB Lappert MF Nycz JE 《Dalton transactions (Cambridge, England : 2003)》2004,(4):499-501
Treatment of P(X)(X')Cl with KC8 gave the crystalline diphosphine [P(X)X']2 (1) which dissociated reversibly into the phosphinyl radical *P(X)X' (2), a plausible intermediate in the reaction of with [Cr(CO)6], [Co(NO)(CO)3] or P4, yielding [Cr[P(X)X']2(CO)3] (3), [Co[P(X)X'](CO)3] (4), or 1,4-P4[P(X)X']2 (5); the P(X)X' substituent is pyramidal at P in but planar in [X = N(SiMe3)2, X'= NPri2]. 相似文献
4.
Annika Arndt Damir Posavec Stefan Schwarzer Mathias S. Wickleder Prof. Dr. 《无机化学与普通化学杂志》2008,634(3):431-435
The reaction of the nitrates M(NO3)3·6H2O (M = La, Pr) and (H3O)2PtCl6 led to yellow single crystals of [M(NO3)2(H2O)6]2[PtCl6]·2H2O (M = La, Pr) (monoclinic, P21/c, Z = 2, La/Pr: a = 697.4(3)/695.5(1), b = 1654.5(1)/1652.5(2), c = 1317.7(6)/1318.5(3) pm, β = 93.97°(7)/93.93°(2), Rall = 0.0169/0.0659) while the reaction of M(NO3)3·5H2O (M = Gd, Dy) and (H3O)2PtCl6 yielded yellow single crystals of [M(NO3)(H2O)7][PtCl6]·4H2O (monoclinic, P21/n, Z = 4, Gd/Dy: a = 838.72(3)/838.40(2), b = 2131.98(6)/2139.50(7), c = 1142.63(3)/1143.10(3) pm, β = 95.670(4)/95.698(3), Rall = 0.0475/0.0337). The crystal structures consist of octahedral [PtCl6]2? anions and complex [M(NO3)2(H2O)6]2+ and [M(NO3)(H2O)7]2+ cations, respectively. The thermal decomposition of both types of compounds leads via various steps to elemental platinum and the oxide chlorides MOCl (M = La, Pr, Gd, Dy). 相似文献
5.
1INTRODUCTIONRecently,therehasbeenconsiderableinterestinthelanthanide(III)hexacyanoferrates,theanalogoushexacyanocobaltateandhexacyanochromiumatecom-plexesbecauseoftheirpotentialapplicationsascata-lyticandsemi-conductivematerials.InitialstudiesofmetalhexacyanocobaltateswerecarriedoutbyJa-mesandWilland[1]whoreportedtheamountofhy-drationassociatedwithmicroscopiccrystalsofsever-allanthanidecomplexes.FurtherBonnetandParis[2]studiedtheLNCo(CN)6?nH2Oseries(n=4)byusinginfraredandX-raymethod… 相似文献
6.
《Chemical physics letters》1986,123(3):182-186
EPR studies have been carried out in Mn2+-doped paramagnetic single crystals of [Co(H2O)6]SiF6, [Co(H2O)6]SnF6 and [Co(H2O)6]PtCl6 at different temperatures using X-band microwave frequency. Reasonably sharp resonance lines of Mn2+ have been obtained at room temperature and analysed using the spin Hamiltonian for trigonal symmetry. From the observed linewidths of Mn2 + in single-crystal [Co(H2O)6]SiF6 the T1 of Co2 + has been estimated to be = 3.3 × 10−11 s. A st phase transition in [Co(H2O)6]SiF6 was observed and the low-temperature phase studied. 相似文献
7.
8.
Safin DA Babashkina MG Robeyns K Garcia Y 《Dalton transactions (Cambridge, England : 2003)》2012,41(15):4324-4327
Reaction of the potassium salt of N-thiophosphorylated thiourea 6-MeO(O)CC(6)H(4)NHC(S)NHP(S)(OiPr)(2) (HL) with PdX(2) (X = Cl(-), Br(-), I(-)) leads to the dark red binuclear complexes [(PdLX)(2)], while the same reaction with PdY(2) (Y = NO(3)(-), CN(-), CH(3)COO(-)) leads to the light red mononuclear complex [PdL(2)]. [PdL(2)] exhibits reversible photoinduced cis-isomerization upon irradiation at 365 or 450 nm, reverting back to the trans-isomer in darkness or upon irradiation at 546 nm. 相似文献
9.
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
10.
The results of DSC measurements in the temperature range 140–370 K on nine crystalline compounds of the type [M(H2O)6](ClO4)2, where M=Mg, Mn, Fe, Co, Ni, Cu, Zn, Cd and Hg, are discussed. Anomalies detected in the DSC curves are related to the existence
of solid-solid phase transitions and/or to the melting points of these compounds. In consequence of two different hypothetical
structural modifications of [Fe(H2O)6](ClO4)2, two DSC curves are obtained. For the compounds with M=Fe, Cd and Hg, new phase transitions have been discovered. The transition
temperatures of the other phase transitions are in good agreement with literature data obtained by adiabatic calorimetry.
For the compounds with M=Mg, Ni and Cd, DTA measurements were also carried out and the melting points of theses compounds
were established.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
Albayrak C Soylu AM Dag O 《Langmuir : the ACS journal of surfaces and colloids》2008,24(19):10592-10595
The mixture of two surfactants (C12EO10-CTAB and C12EO10-SDS) forms lyotropic liquid-crystalline (LLC) mesophases with [Zn(H2O)6](NO3)2 in the presence of a minimum concentration of 1.75 H2O per C12EO10. The metal ion/C12EO10 mole ratio can be increased up to 8.0, which is a record high metal ion density in an LLC mesophase. The metal ion concentration can be increased in the medium by increasing the CTAB/C12EO10 or SDS/C12EO10 mole ratio at the expense of the stability of the LLC mesophase. The structure and some thermal properties of the new mesophase have been investigated using XRD, POM, FTIR, and Raman techniques. 相似文献
12.
以硝酸铜和对氯苯氧乙酸为原料,合成了标题化合物[Cu(C8H6ClO3)2(H2O)2],并用元素分析仪、红外光谱仪、X射线单晶衍射仪表征了其组成和晶体结构.结果表明,所合成的晶体属三斜晶系,Pi空间群,a=0.51146(6)nm,b=0.70640(8)nm,c=1.326410(15)nm,a=81.7770(10)°,β=86.361(2)°,γ=76.3970(10)°,F(000)=239,Z=1;最终偏离因子R=0.0264,wR=0.0674.在配合物中,铜离子与来自两个对氯苯氧乙酸根的两个羧基氧原子、两个醚氧原子以及来自两个水分子的氧原子配位,形成变形八面体结构. 相似文献
13.
Alexander I. Gubanov Natalia V. Kuratieva 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(10):i83-i85
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. 相似文献
14.
Kou HZ Tang JK Liao DZ Gao S Cheng P Jiang ZH Yan SP Wang GL Chansou B Tuchagues JP 《Inorganic chemistry》2001,40(19):4839-4844
Two bimetallic assemblies, [Ni(tn)(2)](2)[Cr(CN)(5)(NO)]OH.H(2)O (1) and [Ni(tn)(2)](2)[Co(CN)(6)]NO(3).2H(2)O (2) (tn = 1,3-diaminopropane), have been prepared and structurally and magnetically characterized. Crystal data for 1 (2): space group P1 (P1), a = 8.698(3) (8.937(2)) A, b = 10.001(2) (9.863(1)) A, c = 10.158(2) (10.064(1)) A, alpha = 87.40(2) (86.064(10)) degrees, beta = 65.10(2) (65.489(10)) degrees, gamma = 81.63(2) (81.572(12)) degrees and Z = 1 (1). Both structures consist of two-dimensional grid-like polycations containing Ni-N triple bond C-M linkages (M = Cr or Co) and counteranions (OH, NO(3)). Magnetic studies of 1 showed that the complex displays a metamagnetic behavior originating from intralayer ferromagnetic and interlayer antiferromagnetic interactions. Long-range antiferromagnetic ordering was observed at T(N) = 3.3 K. Complex 2 exhibits intramolecular ferromagnetic interactions through the diamagnetic N triple bond C-Co-N triple bond C bridges, owing to superexchange involving the empty d(sigma) orbital of the diamagnetic Co(III) ion. 相似文献
15.
The novel Ru(II)-supported heteropolytungstates [Ru(dmso)(3)(H(2)O)XW(11)O(39)](6-)(X = Ge, Si) have been synthesized and characterized by single-crystal X-ray diffraction, multinuclear NMR ((183)W, (13)C, (1)H, (29)Si) and IR spectroscopy, elemental analysis and electrochemistry. The novel polyanion structure consists of a Ru(dmso)(3)(H(2)O) unit linked to a monolacunary [XW(11)O(39)](8-) Keggin fragment via two Ru-O-W bonds resulting in an assembly with C(1) symmetry. Polyanions 1 and 2 were synthesized by reaction of cis-Ru(dmso)(4)Cl(2) with [A-alpha-XW(9)O(34)](10-) in aqueous, acidic medium (pH 4.8). Tungsten-183 NMR of 1 leads to a spectrum with 11 peaks of equal intensity, indicating that the solid-state structure is preserved in solution. Electrochemistry studies revealed that 1 and 2 are stable in solution at least from pH 0 to 7, even in the presence of dioxygen. Their cyclic voltammetry patterns show mainly two two-electron reversible W-waves, those of the Si derivative 2 being located at slightly more negative potentials than those of the Ge derivative 1. The observed stability of 1 and 2 might be attributed to a stabilization of the Ru-center both by the strongly bound dmso ligands and the Keggin moiety. This stabilization drives the redox waves of Ru outside the accessible potential range. However, conditions were found to reveal, at least partially, the redox behavior of Ru in 1 and 2. 相似文献
16.
Ruthenium-terpyridine complexes incorporating a 2,2'-dipyridylamine ancillary ligand [Ru(II)(trpy)(L)(X)](ClO(4))(n) [trpy = 2,2':6',2' '-terpyridine; L = 2,2'-dipyridylamine; and X = Cl(-), n = 1 (1); X = H(2)O, n = 2 (2); X = NO(2)(-), n = 1 (3); X = NO(+), n = 3 (4)] were synthesized in a stepwise manner starting from Ru(III)(trpy)(Cl)(3). The single-crystal X-ray structures of all of the four members (1-4) were determined. The Ru(III)/Ru(II) couple of 1 and 3 appeared at 0.64 and 0.88 V versus the saturated calomel electrode in acetonitrile. The aqua complex 2 exhibited a metal-based couple at 0.48 V in water, and the potential increased linearly with the decrease in pH. The electron-proton content of the redox process over the pH range of 6.8-1.0 was calculated to be a 2e(-)/1H(+) process. However, the chemical oxidation of 2 by an aq Ce(IV) solution in 1 N H(2)SO(4) led to the direct formation of corresponding oxo species [Ru(IV)(trpy)(L)(O)](2+) via the concerted 2e(-)/2H(+) oxidation process. The two successive reductions of the coordinated nitrosyl function of 4 appeared at +0.34 and -0.34 V corresponding to Ru(II)-NO(+) --> Ru(II)-NO* and Ru(II)-NO* --> Ru(II)-NO(-), respectively. The one-electron-reduced Ru(II)-NO* species exhibited a free-radical electron paramagnetic resonance signal at g = 1.990 with nitrogen hyperfine structures at 77 K. The NO stretching frequency of 4 (1945 cm(-1)) was shifted to 1830 cm(-1) in the case of [Ru(II)(trpy)(L)(NO*)](2+). In aqueous solution, the nitrosyl complex 4 slowly transformed to the nitro derivative 3 with the pseudo-first-order rate constant of k(298)/s(-1) = 1.7 x 10(-4). The chloro complex 1 exhibited a dual luminescence at 650 and 715 nm with excited-state lifetimes of 6 and 1 micros, respectively. 相似文献
17.
18.
In the title complexes the cis-benzenetrioxide acts as tridentate ligand, allowing for octahedral and unusual tetracapped trigonal prismatic coordination (TECTP). 相似文献
19.
Jakob
sterberg Eriksen Alan Hazell Astrid Jensen Josua Jepsen Rasmus Damgaard Poulsen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):551-553
The reaction between tris(ethylenediamine)nickel(II) cations and hexacyanometallate(III) anions (M = Fe, Co) yields ordered bimetallic assemblies, catena‐poly[[tris(ethylenediamine)nickel‐bis(μ‐hexacyanoiron‐N,N′)] trihydrate] and catena‐poly[[tris(ethylenediamine)nickel‐bis(μ‐hexacyanocobalt‐N,N′)] trihydrate], [{Ni(C2H8N2)2}3{M(CN)6}2]·3H2O, in which both cis and trans [Ni(en)2] and [M(CN)6] moieties are linked to give S‐shaped Ni–NC–M–CN–Ni–NC–M–CN–Ni units which are crosslinked to give ribbons parallel to the b axis. The two compounds are isomorphous with mean metal–ligand distances Fe—C = 1.940 (3), Co—C = 1.844 (3) and Ni—N = 2.102 (2) Å for the iron, and 2.105 (3) Å for the cobalt compound. These compounds appear to be identical with those formulated as [Ni(en)2]3[M(CN)6]2·2H2O [Ohba, Maruona, Okawa, Enoki & Latour (1994). J. Am. Chem. Soc. 116 , 11566–11567; Ohba, Fukita & Okawa (1997). J. Chem. Soc. Dalton Trans. pp. 1733–1737] which were indexed on a smaller unit cell and described as disordered. 相似文献