Ship-in-a-bottle formation of Ru3(CO)12 in zeolite NaY

A NaY zeolite entrapped Ru₃(CO)₁₂ cluster has been synthesized from RuCl₃ ionexchanged NaY, which are well characterized by IR and Raman spectroscopy and CO chemisorption. When the Ru³⁺/NaY sample is heated from 298 to 393 K for 25 h and kept for 10–20 h at 393 K, the sample color changes from dark to brown-yellow. Thein situ infrared spectrum exhibits bands at 2130, 2064, 2040, 2017, 1990, 1953 and 1925 cm⁻¹. The bands at 2064, 2040, 2017 and 1990 cm⁻¹ are assigned to Ru₃(CO)₁₂/NaY, which are close to crystalline Ru₃(CO)₁₂. Furthermore, Raman results provide the bands at 150 and 185 cm⁻¹, which are attributed to Ru-Ru bonds of crystalline Ru₃(CO)₁₂). CO chemisorption on [Ru₃]/NaY gives a CO/Ru ratio of 3.85, which is similar to the stoichiometry of Ru₃(CO)₁₂ (CO/Ru=4.0).     

Chirality and Relativistic Effects in Os3(CO)12

The energy and structural parameters were obtained for all forms of the carbonyl complex of osmium Os₃(CO)₁₂ with D_3h and D₃ symmetries using density functional theory (DFT) methods. The calculations took into account various levels of relativistic effects, including those associated with nonconservation of spatial parity. It was shown that the ground state of Os₃(CO)₁₂ corresponds to the D₃ symmetry and thus may be characterized either as left-twisted (D_3S) or right-twisted (D_3R). The D_3S↔D_3R transitions occur through the D_3h transition state with an activation barrier of ~10^–14 kJ/mol. Parity violation energy difference (PVED) between D_3S and D_3R states equals to ~5 × 10⁻¹⁰ kJ/mol. An unusual three-center exchange interaction was found inside the {Os₃} fragment. It was found that the cooperative effects of the mutual influence of osmium atoms suppress the chirality of the electron system in the cluster.     

Convenient method for the synthesis of phthalazinones via carbonylation of 2-bromobenzaldehyde using Co2(CO)8 as a CO source

A simple one-pot synthesis of phthalazinones by the condensation and intra-molecular carbonylative cyclization of 2-bromobenzaldehydes with hydrazines is reported. This method utilizes solid Co₂(CO)₈ as carbonyl source making it readily accessible in small-scale laboratory applications.     

Non-empirical pseudopotentials (PSIBMOL algorithm) for molecular calculations: The Rh2Cl2(CO)4 complex

The electronic structure of Rh₂Cl₂(CO)₄ in the ground state is computed using the recently proposed PSIBMOL (Pseudo-potentials + IBMOL/H) formalism. The drawing of the total and differential isoelectronic contour maps supports the idea that there does not exist any rhodium-rhodium bond in such a binuclear complex, the origins of the preferred bent conformation having to be found elsewhere.     

新型配合物Mn2Hg4(SCN)12的合成与晶体结构分析

A new inorganic coordination compound Mn₂Hg₄(SCN)₁₂ was synthesized. The grown crystals were characterized by elemental analysis, infrared spectroscopic analysis and powder crystal X-ray diffraction in detail. The crystal structure of Mn₂Hg₄(SCN)₁₂ was determined by single-crystal X-ray diffraction. It belongs to monoclinic system, P2₁/c space group. The cell dimensions are: a=1.171 6 nm, b=1.431 05 nm, c=2.105 1 nm, β=100.738°, and Z=4. In the structure of it, half of Mn²⁺ cations have five-coordinate number, and other half of Mn²⁺ cations have six-coordinate number; 3/4 of Hg²⁺ cations are coordinated by four SCN^-, 1/4 of Hg²⁺ cations are coordinated by three SCN^- and one NCS^-, all the coordination geometry of Hg²⁺ show slightly distorted tetrahedrons. CCDC: 244939.     

Die Kristallstruktur von Dikalium-trikobalt(II)-dihydroxid-trisulfat-dihydrat,K2Co3(OH)2(SO4)3·2H2O

Crystals of K₂Co₃(OH)₂(SO₄)₃·2H₂O were synthesized under hydrothermal conditions. The crystal structure [a=17.945 (4) Å,b=7.557 (2) Å,c=9.760 (3) Å, space group Cmc2₁,Z=4] was determined by direct methods and refined with single crystal X-ray data. The H atoms were located byFourier syntheses. Their structural parameters were refined, too. The finalR-values areR=0.025 andR _w =0.028 (w=1/) for 612 reflections withF ₀>3 (F ₀). Both Co(II) atoms are octahedral six coordinated and form zigzag chains running parallel [001]. These chains are connected via sulfate groups to built up sheets parallel (100). The KO₉ polyhedron and one of the four hydrogen bonds link these sheets.

     

FT-IR photoacoustic spectra of the surface of Ru3(CO)12/Al2O3 system

The FT-IR photoacoustic spectra of Ru₃(CO)₁₂/Al₂O₃ (acidic and basic alumina) system have been measured for different ageing times. The behaviors of oxidation states of Ru on the surface of basic or acidic alumina and their difference are discussed on the ground of CO stretching bands of their spectra.     

A comparison of quantitative theoretical results of the bonding in Ni(CO)4 and Ni(N2)4

Using non-empirical calculations the details of bonding in Ni(CO)₄ and in the analogous Ni(N₂)₄ are investigated.For Ni(CO)₄ some previous results are confirmed. In the calculation on Ni(N₂)₄ the close resemblance with Ni(CO)₄ is quite remarkable. The main difference is contained in the fact that carbon has a lower -electron density than nitrogen and that therefore the *-orbital in CO is lower in energy and geometrically more favourable for back donation.From the calculations we find a difference in metal-ligand bond energy between the carbonyl complex and the dinitrogen complex of approximately 18 kcal/mol.     

Kinetics of the thermal decomposition of [Co(NH3)6]2(C2O4)3·4H2O

The thermal decomposition of [Co(NH₃)₆]₂(C₂O₄)₃·4H₂O was studied under isothermal conditions in flowing air and argon. Dissociation of the above complex occurs in three stages. The kinetics of the particular stages thermal decomposition have been evaluated. The R_N and/or A_M models were selected as those best fitting the experimental TG curves. The activation energies,E, and lnA were calculated with a conventional procedure and by a new method suggested by Kogaet al. [10, 11]. Comparison of the results have showed that the Arrhenius parameters values estimated by the use of both methods are very close. The calculated activation energies were in air: 96 kJ mol^–1 (R_1.575, stage I); 101 kJ mol^–1 (Ain1.725 stage II); 185 kJ mol^–1 (A _2.9, stage III) and in argon: 66 kJ mol^–1 (A _1.25, stage I); 87 kJ mol^–1 (A _1.825, stage II); 133 kJ mol^–1 (A _2.525, stage III).     

IR STUDIES OF THE THERMAL DECOMPOSITION OF[Rh_6(CO)_(16) Co_4(CO)_(12)]/SiO_2: EVIDENCE FOR THE FORMATION OF RhCo_3(CO)_(12)/SiO_2

IntroductionThepreparativeapproachofaneffectivebilTldslliccatalystisalwaysasubjectofboortantsignificanceinheterogeneouscatalysis.InourrecentstUdies,wefoundthatthebAnetallitcarbonylclustercoCo3(CO)12favorablygivesthebAnetalliccoCo3clusterontheSiOZsubdueaft…     

SiO44-对Li3Sc2(PO4)3快离子导体的阴离子替代效果研究

Li3Sc2(PO4)3因具有有利的离子传导通道、低的电子电导率和高的稳定性而成为全固态锂离子电池用固体电解质最具竞争力的材料之一,然而这一化合物只有在245℃以上的γ相才具有快离子传导特性。人们主要采用Zr4+、Ti4+等阳离子部分取代其中的Sc3+以改善材料的室温电导率,有关该化合物PO43-阴离子替代的报道还很少。本研究试图利用机械研磨技术,通过向Li3Sc2(PO4)3原料混合物中加入适量SiO2,以期能够实现对该化合物的部分阴离子替代。研究结果表明:所制备的Li3+xSc2(PO4)3-x(SiO4)x(x=0~0.6)系列化合物在x=0.15时电导率达到最大值,σ298=9.55×10-4 S.m-1,离子传导激活能达到最小值45.06 kJ.mol-1。29Si MAS-NMR测试结果证实所加入的SiO2主要以[SiO4]四面体形式存在替代Li3Sc2(PO4)3中部分[PO4]四面体。     

Multinuclear NMR studies on substituted derivatives of Rh6(CO)16 in solution

Multinuclear NMR data (¹³C, ³¹P, ¹³C–{³¹P}, ¹³C–{¹⁰³Rh} and ³¹P–{¹⁰³Rh}) for a series of mono- and di-substituted derivatives of Rh₆(CO)₁₆ containing neutral two electron donor ligands [Rh₆(CO)₁₅L, (L=NCMe, py, cyclooctene, PPh₃, P(OPh)₃,1/2(μ₂,η¹:η¹-dppe)); Rh₆(CO)₁₄(LL), (LL=cis-CH₂=CMe-CMe=CH₂, dppm, dppe, (P(OPh)₃)₂)] are reported; these data show that the solid state structure is maintained in solution. Detailed assignments of the ¹³CO NMR spectra of Rh₆(CO)₁₅(PPh₃) and Rh₆(CO)₁₄(dppm) clusters have been made on the basis ¹³C–{¹⁰³Rh} double resonance measurements and the specific stereochemical features of the observed long range couplings in these clusters have been studied. The stereochemical dependence of ³J(P–C) for terminal carbonyl ligands is discussed and the values of ³J(P–C) are found to be mainly dependent on the bond angles in the P–Rh–Rh–C fragment; these data enable the fine structure of the complex multiplets in the ¹³C–{¹H} and ³¹P–{¹H} NMR spectra of Rh₆(CO)₁₄ (dppm) to be simulated. Variable temperature ¹³C–{¹H} NMR measurements on Rh₆(CO)₁₅(PPh₃) reveal the carbonyl ligands in this complex to be fluxional. The fluxional process involves exchange of all the CO ligands except the two terminal CO's associated with the rhodium trans to the substituted rhodium and can be explained by a simple oscillation of the PPh₃ on the substituted rhodium atom aided by concomitant exchange of the unique terminal CO on this rhodium with adjacent μ₃-CO's.     

Decomposition of P2S2N4(Si(CH3)3)4A12C14 as Studied by FT-Raman and Quantum Chemistry Means

The dimeric title compound decomposes upon heating to give the monomer and desulphurized monomer as shown by FT-Raman and quantum chemical means.     

Tailoring Electrochemical Performance of Co3O4 Electrode Materials by Mn Doping

Reasonable design of electrode materials is the key to solving the low energy density of the supercapacitors. Transition metal oxide Co₃O₄ material is commonly used in the field of supercapacitors, but the poor cycle stability limits its practical application. Herein, we report 0.3Mn-Co₃O₄ nanostructures grown on nickel foam by a facile one-step hydrothermal approach. The morphology of the samples can be regulated by the introduction of different amounts of Mn ions. The specific capacitance reaches 525.5 C/g at 1 A/g. The performance of 0.3Mn-Co₃O₄ material is significantly improved due to its excellent stability and conductivity, which makes it a suitable electrode material for supercapacitors. A flexible asymmetric device is also fabricated using the sample as the cathode. The assembled capacitor still possesses a desirable cycle stability after charging and discharging of 10,000 times, and its capacitance retention rate can reach 83.71%.     

The influence of oxygen pressure on the kinetics of the thermal decomposition of Co3O4

The kinetics of the thermal decomposition of Co₃O₄ has been examined in the 1123–1200 K temperature and 2.66–20.73 kPa oxygen pressure range. The kinetics of this process has been deseribed in terms of a mixed-control model of reaction. The values of activation energies of diffusion and chemical reaction as well as the observed activation energy have been given. The strong dependence of the decomposition rate on temperature and oxygen pressure has been explained.     

一个新的双核锌配合物Zn2(dhaash)2(py)4的合成及晶体结构

The crystal of binuclear zinc complex Zn₂(dhaash)₂(py)₄ was obtained in DMF and pyridine, where H₂dhaash is 2,4-dihydroxy-5-acetylacetophenone-N-salicylhydrazone. It has been characterized by IR, UV, element analysis and X-ray single crystal diffraction. The crystallographic data were as follows: monoclinic system, space group P2₁/c, a=1.108 98(11) nm, b=1.640 84(16) nm, c=1.445 14(14) nm, β=108.617(2)°, Z=2, V=2.492 1(4) nm³, D_c=1.466 g·cm^-3, M_r=1 099.74, μ=1.031 mm^-1, F(000)=1 136 and the final R=0.044 8 and wR=0.105 8 for 4 143 observed reflections with I≥2σ(I), respectively. The X-ray crystal structure analysis revealed that, in the centrosymmetric binuclear complex molecule, two zinc(Ⅱ) centers are linked by two oxygen atoms (O(3) and O(3A)), respectively. Zn(1)…Zn(1A) distance is 0.314 81(6) nm, O(3)…O(3A) distance is 0.270 4(2) nm. Every zinc(Ⅱ) ion has an elongated octahedral coordination. For example, the two pyridine nitrogen atoms, one oxygen atom and one nitrogen atom from salicylhydrazone, one oxygen atom from 2,4-dihydroxy-5-acetylacetophenone in one dhaash^2- ligand and one oxygen atom from 2,4-dihydroxy-5-acetylacetophenone in another dhaash^2- ligand coordinated to zinc(Ⅱ) ion, respectively. Two zinc(Ⅱ) ions and all the 72 non-hydrogen atoms in the two dhaash^2- ligands are in the same plane. CCDC: 261929.     

Syntheses and crystal structures of NH4Ag2(AsS2)3 and (NH4)5Ag16(AsS4)7 with a discussion of (NH4)Sx polyhedra

Summary The atomic arrangements within the structures of NH₄Ag₂(AsS₂)₃ [a=9.557(2),b=7.414(2),c=16.29(1) Å; =91.30(5)°; space group P2₁/n;R(F)=0.042] and (NH₄)₅Ag₁₆(AsS₄)₇ [a=64.49(6),b=6.471(2),c=12.806(4) Å; =95.47(5)°; space group Cc;R(F)=0.073] were determined from single crystal X-ray data. In these two compounds the coordination spheres of the Ag atoms are quite different. In NH₄Ag₂(AsS₂)₃, the Ag atoms exhibit a [2+2]- and a [3+1]-coordination to S atoms up to 3.3 Å and with Ag atom neighbours at 2.93 Å and 3.05 Å respectively. In (NH₄)₅Ag₁₆(AsS₄)₇, the Ag atoms are — with one exception- [4] coordinated (Ag-S<3.3 Å) and the distances to further Ag atom neighbours are greater than 3.1 Å. NH₄Ag₂(AsS₂)₃ represents an ordered cyclo-thioarsenate(III) with three-membered As₃S₆ rings, (NH₄)₅Ag₁₆(AsS₄)₇ a neso-thioarsenate(V) with two split Ag atom positions. Both compounds were synthesized under moderate hydrothermal conditions.

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Synthesen und Kristallstrukturen von NH₄Ag₂(AsS₂)₃ und (NH₄)₅Ag₁₆(AsS₄)₇ mit einer Diskussion über (NH₄)S_x Polyeder

Zusammenfassung Die Atomanordnungen in den Strukturen von NH₄Ag₂(AsS₂)₃ [a=9.557(2),b=7.414(2),c=16.29(1) Å; =91.30(5)°; Raumgruppe P2₁/n;R(F)=0.042] und (NH₄)₅Ag₁₆(AsS₄)₇ [a=64.49(6),b=6.471(2),c=12.806(4) Å; =95.47(5)°; Raumgruppe Cc;R(F)=0.073] wurden anhand von röntgenographischen Einkristalldaten bestimmt. In diesen beiden Verbindungen sind die Koordinationsverhältnisse um die Ag-Atome sehr unterschiedlich. In NH₄Ag₂(AsS₂)₃ besitzen die Ag-Atome bis 3.3 Å eine [2+2]- und [3+1]-Koordination durch S-Atome mit weiteren Ag-Atomen bei 2.93 Å und 3.05 Å. In (NH₄)₅Ag₁₆(AsS₄)₇ sind die Ag-Atome mit einer Ausnahme [4]-koordiniert (Ag-S < 3.3 Å), und die Abstände zu weiteren Ag-Atomen sind größer als 3.1 Å. NH₄Ag₂(AsS₂)₃ stellt ein geordnetes Cyclothioarsenat(III) mit dreigliedrigen As₃S₆-Ringen dar, (NH₄)₅Ag₁₆(AsS₄)₇ ein Nesothioarsenat (V) mit zwei aufgespaltenen Ag-Positionen. Beide Verbindungen wurden unter mäßigen Hydrothermalbedingungen synthetisiert.

     

Synthesis of Co3O4 nanoparticles by oxidation-reduction method and its magnetic characterization

Without any surfactant, antiferromagnetic Co₃O₄ nanoparticles were synthesized successfully for the first time by means of an oxidation-reduction method with cobalt sulfate as starting material, which was oxidized to cobalt salt by NaNO₃ after alkalinizing with NaOH. Morphological, structural, spectroscopic and magnetic characterization of the product were done by SEM, TEM, XRD, and VSM, respectively. The average crystallite size (on the base of line profile fitting method), D and σ, is estimated as 30 ± 6 nm. Some anomalous magnetic properties and their enhanced effect have been observed in Co₃O₄ antiferromagnetic nanocrystallites, including a bias field, coercivity, permanent magnetic moments and an open loop. These phenomena are attributed to the unidirectional anisotropy which is caused by the exchange coupling between AFM and FM layers, the existence of the spin glass like surface spins of Co₃O₄ nanoparticles due to size effects and surface-area effect.