Synthesis,structure, and some reactions of the cluster complex [(μ-H)<Subscript>2</Subscript>Fe<Subscript>5</Subscript>(μ<Subscript>3</Subscript>-Se)<Subscript>2</Subscript>(CO)<Subscript>14</Subscript>]

In the reaction of Na₂Se with [Fe(CO)₅] in isopropanol with subsequent acidification with HCl, which is used to synthesize [(μ-H)₂Fe₃(μ₃-Se)(CO)₉] (II), the cluster [(μ-H)₂Fe₅(μ₃-Se)₂(CO)₁₄] (I) was detected. In assumption that compound I could serve as a suitable synthon for preparing the bulky heterometallic clusters, its reactions with the Rh-containing complexes were studied. The reaction of I with [Rh(CO)₂Cp*] (Cp* is pentamethylcyclopentadienyl) was found to give a mixture of the products. The main reaction products were isolated and their structures were determined: [Fe₂Rh(μ₃-Se)₂(CO)₆Cp*], [Fe₂Rh(μ₃-Se)(μ₃-CO)(CO)₆Cp*], [FeRh₂(μ₃-Se)(μ-CO)(CO)₃Cp ₂ ^* ], [Fe₂Rh₂(μ₄-Se)(μ-CO)₄(CO)₂Cp ₂ ^* ]. Potassium hydride treatment of II with subsequent addition of [Cp*Rh(CH₃CN)₃](CF₃SO₃)₂ leads to the well-known cluster complex [Fe₃Rh(μ₄-Se)(CO)₉Cp*]. A set of the reaction products indicates that the {Fe₅Se₂} core cannot be used as one-piece “building block” in the synthesis of heterometallic clusters.     

Hydroethoxycarbonylation of α-olefins at low pressure of carbon(II) oxide in the presence of the PdCl<Subscript>2</Subscript>(PPh<Subscript>3</Subscript>)<Subscript>2</Subscript>–PPh<Subscript>3</Subscript>–AlCl<Subscript>3</Subscript> system

High catalytic activity of the PdCl₂(PPh₃)₂–PPh₃–AlCl₃ system containing AlCl3 as promotor has been demonstrated in the reaction of hydroethoxycarbonylation of hexene-1 and octene-1 at low pressure of carbon(II) oxide (≤25 atm). The reaction yields linear and branched products. The optimal conditions of the process have been elaborated. The target products yield is 84.6–93.8%.     

[Ca(OPPh<Subscript>3</Subscript>)<Subscript>5</Subscript>][Mo<Subscript>6</Subscript>(μ<Subscript>3</Subscript>-Cl)<Subscript>8</Subscript>Cl<Subscript>6</Subscript>] · OPPh<Subscript>3</Subscript>: Synthesis and crystal structure

A solvatothermal reaction of the octahedral cluster molybdenum complex (H₃O)₂[Mo₆(μ₃-Cl)₈Cl₆] · 6H₂O with CaCl₂ · 6H₂O and OPPh₃ in acetonitrile gave the known polymeric complex trans-[{Ca(OPPh₃)₄}{Mo₆(μ₃-Cl)₈Cl₆}]_∞. However, a closer examination revealed that this system also produces a novel cluster complex, [Ca(OPPh₃)₅][Mo₆(μ₃-Cl)₈Cl₆] · OPPh₃, which was isolated and characterized by X-ray diffraction.     

Crystal structure of [Pb<Subscript>3</Subscript>(OH)<Subscript>4</Subscript>Co(NO<Subscript>2</Subscript>)<Subscript>3</Subscript>](NO<Subscript>3</Subscript>)(NO<Subscript>2</Subscript>)·2H<Subscript>2</Subscript>O

The structure of [Pb₃(OH)₄Co(NO₂)₃](NO₃)(NO₂)·2H₂O is determined by single crystal X-ray diffraction. The crystallographic characteristics are as follows: a = 8.9414(4) Å, b = 14.5330(5) Å, c = 24.9383(9) Å, V = 3240.6(2) ų, space group Pbca, Z = 8. The Co(III) atoms have a slightly distorted octahedral coordination formed by three nitrogen atoms belonging to nitro groups (Co–N_av is 1.91 Å) and three oxygen atoms belonging to hydroxyl groups (Co–O_av is 1.93 Å). The hydroxyl groups act as μ₃-bridges between the metal atoms. The geometric characteristics are analyzed and the packing motif is determined.     

Induced currents and an <Superscript>1</Superscript>H NMR chemical shifts in transition metal clusters (μ-H)<Subscript>2</Subscript>Fe<Subscript>3</Subscript>(μ<Subscript>3</Subscript>-Q)(CO)<Subscript>9</Subscript> (Q = S,Se, Te)

The quantum chemical calculations of induced electric currents in (μ-H)₂Fe₃(μ₃-Q)(CO)₉ complexes, where Q = S, Se, Te, are carried out. It is demonstrated that the appearance of anomalous ¹Н NMR chemical shifts on bridging hydrogen atoms is, first of all, due to the effect of induced currents on iron atoms.     

Synthesis and structure of the complex [Mo<Subscript>3</Subscript>(μ<Subscript>3</Subscript>-S)(μ<Subscript>2</Subscript>-S<Subscript>2</Subscript>)<Subscript>3</Subscript>(Et<Subscript>2</Subscript>NCS<Subscript>2</Subscript>)<Subscript>3</Subscript>]I

The structure of tri-μ₂-disulfido-μ₃-thiotris(diethyldithiocarbamato)-S,S′-triangle-trimolybdenum iodide [Mo₃(μ₃-S)(μ₂-S₂)₃(Et₂NCS₂)₃]I was determined. The compound was characterized by differential thermal analysis and IR, Raman, and X-ray electronic spectroscopy.     

Lanthanide-Organic Frameworks Based on {Ln<Subscript>4</Subscript>(μ<Subscript>3</Subscript>-OH)<Subscript>4</Subscript>(μ<Subscript>2</Subscript>-OH)<Subscript>2</Subscript>} Cluster Units

Abstract  

Three novel lanthanide-organic frameworks: [Ln₂(pyba)₃(μ₃-OH)₂(μ₂-OH)(H₂O)] _n (Ln = Er (1), Y (2), Dy (3) Hpyba = 4-pyridin-4-yl-benzoic acid) have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Structure analysis shows that each {Ln₄(μ₃-OH)₄(μ₂-OH)₂} cluster units interconnect to form 1-D chains, which are further linked by π–π interactions to make a 3-D supramolecular network structure. Furthermore, the IR, PXRD and TGA of compounds 1–3 were also studied.     

Synthesis and thermal analysis of indium-based hydrotalcites of formula Mg<Subscript>6</Subscript>In<Subscript>2</Subscript>(CO<Subscript>3</Subscript>)(OH)<Subscript>16</Subscript>·4H<Subscript>2</Subscript>O

Insight into the unique structure of layered double hydroxides (LDHs) has been obtained using a combination of X-ray diffraction and thermal analysis. Indium containing hydrotalcites of formula Mg₄In₂(CO₃)(OH)₁₂·4H₂O (2:1 In-LDH) through to Mg₈In₂(CO₃)(OH)₁₈·4H₂O (4:1 In-LDH) with variation in the Mg:In ratio have been successfully synthesised. The d(003) spacing varied from 7.83 Å for the 2:1 LDH to 8.15 Å for the 3:1 indium containing LDH. Distinct mass loss steps attributed to dehydration, dehydroxylation and decarbonation are observed for the indium containing hydrotalcite. Dehydration occurs over the temperature range ambient to 205 °C. Dehydroxylation takes place in a series of steps over the 238–277 °C temperature range. Decarbonation occurs between 763 and 795 °C. The dehydroxylation and decarbonation steps depend upon the Mg:In ratio. The formation of indium containing hydrotalcites and their thermal activation provides a method for the synthesis of indium oxide-based catalysts.     

Iridium–Ruthenium Cluster Complexes with SnPh<Subscript>3</Subscript> Ligands from the Reaction of IrRu<Subscript>3</Subscript>(CO)<Subscript>13</Subscript>(μ-H) with HSnPh<Subscript>3</Subscript>

The reaction of IrRu₃(CO)₁₃(μ-H), 1 with HSnPh₃ in hexane solvent at reflux has provided the new mixed metal cluster compounds Ir₂Ru₂(CO)₁₁(SnPh₃)(μ-H)₃, 2 and IrRu₃(CO)₁₁(SnPh₃)₃(μ-H)₄, 3 containing SnPh₃ ligands. Compound 2 which was obtained in low yield (3%) contains one SnPh₃, two iridium atoms and two ruthenium atoms. The increase in the number of iridium atoms must have resulted from a metal–metal exchange process. The major product 3 (19% yield) contains an open cluster of one iridium and three ruthenium atoms with three SnPh₃ ligands and four hydride ligands. Both compounds were characterized structurally by single crystal X-ray diffraction analysis.     

Synthesis of cyclohexyl isovalerate by carbonylation of isobutylene with carbon monoxide and cyclohexanol in the presence of Pd(PPh<Subscript>3</Subscript>)<Subscript>4</Subscript>‒PPh<Subscript>3</Subscript>‒TsOH and its antimicrobial activity

A procedure has been developed for the synthesis of cyclohexyl isovalerate by reaction of isobutylene with carbon monoxide and cyclohexanol in the presence of the three-component catalytic system Pd(PPh₃)₄?PPh₃?TsOH. Cyclohexyl isovalerate showed a pronounced antibacterial activity.     

Exploration of Solvent Effects on the Spectroscopic Properties (Ir and <Superscript>13</Superscript>C NMR) in the OsCl<Subscript>3</Subscript>(≡CCH<Subscript>2</Subscript>CMe<Subscript>3</Subscript>)(PH<Subscript>3</Subscript>)<Subscript>2</Subscript> Carbyne Complex

In this investigation, the spectroscopic properties (IR and ¹³C NMR) of the carbyne complex OsCl₃(≡CCH₂CMe₃)(PH₃)₂ are investigated in the gas and solution phases. The polarizable continuum model is used to study the solvent effect on these parameters. The wavenumbers of selected IR-active vibrations and ¹³C NMR chemical shifts of the carbyne atom in various solvents (acetone, methanol, ethanol, nitromethane, DMSO) are calculated and correlated with the Kirkwood–Bauer–Magat equation and the linear solvation energy relationship.     

A Raman Spectroscopic Study of Aqueous La(CH<Subscript>3</Subscript>CO<Subscript>2</Subscript>)<Subscript>3</Subscript> Solutions and La(CH<Subscript>3</Subscript>CO<Subscript>2</Subscript>)<Subscript>3</Subscript>·1.5 H<Subscript>2</Subscript>O(cr)

Aqueous solutions of La(CH₃CO₂)₃, NaCH₃CO₂ and La(ClO₄)₃ were studied using Raman spectroscopy. In dilute NaCH₃CO₂ solution, acetate is fully hydrated and forms only minor amounts of ion pairs. The characteristic Raman bands are discussed and assigned. In fairly dilute La(ClO₄)₃ solutions, the La³⁺(aq) ion occurs as the nonahydrate. The separation of the carboxylate bands, ν_as – ν_s (Δ-value), in NaCH₃CO₂(cr) compared to La(CH₃CO₂)₃·1.5H₂O(cr) correlates with the bonding type of acetate which is “ionic” in the former but bidentate chelating/tridentate chelating in the latter. Other acetate bands such as the deformation mode of the CO₂ moiety, δ CO₂, and the two rocking vibrations (ρ), as well as the C–C stretch show marked differences in their band positions in NaCH₃CO₂(cr) compared to the ones in La(CH₃CO₂)₃·1.5H₂O(aq). In a ternary solution of La(CH₃CO₂)₃/LaCl₃ with a molar ratio La³⁺(aq): \( {\text{CH}}_{3} {\text{CO}}_{2}^{ - } \)(aq) = 3.87: 1.00), the bands of the bound acetate on La³⁺ were characterized and compared to those of fully hydrated acetate, \( {\text{CH}}_{3} {\text{CO}}_{2}^{ - } \left( {\text{aq}} \right) \). In this solution, almost all acetate is ligated to La³⁺ in a bidentate fashion and two complex species could be identified (molar ratios La³⁺: \( {\text{CH}}_{3} {\text{CO}}_{2}^{ - } \)  = 1:1 and 1:2, respectively). In La(CH₃CO₂)₃ solutions in H₂O and D₂O strong acetato complexes are formed and the bands of the bound acetate were characterized and compared with the ones of the fully hydrated acetate modes. A dilution series down to 0.0037 mol·L^?1 in La(CH₃CO₂)₃(aq) and to 0.0150 mol·L^?1 in La(CH₃CO₂)₃(D₂O) showed that two acetate complexes are formed in these solutions. Again, it was shown that in these solutions the bound acetates on La³⁺ exist as bidentate ligands. DFT frequencies of the acetate on clusters {La(OH₂)₇O₂CCH₃)}²⁺ and {La(OH₂)₅(O₂CCH₃)₂}⁺ compared well with the measured values. By determining the ligation number, \( \bar{n} \), it can be established that in dilute solutions, below 0.04 mol·L^?1, a complex with a 1:1 stoichiometry (La³⁺: \( {\text{CH}}_{3} {\text{CO}}_{2}^{ - } \)) exists in equilibrium with “free” acetate while in more concentrated solutions a 1:2 complex also forms. La³⁺(aq) hydrolysis is slight and very small equilibrium concentrations of CH₃COOH were detected (C–C stretch at 893 cm^?1). From quantitative Raman measurements, K ₁ was determined to be 160 ± 10 at 22 °C.     

Conventional and controlled rate thermal analysis of nesquehonite Mg(HCO<Subscript>3</Subscript>)(OH)·2(H<Subscript>2</Subscript>O)

The understanding of the thermal stability of magnesium carbonates and the relative metastability of hydrous carbonates including hydromagnesite, artinite, nesquehonite, barringtonite and lansfordite is extremely important to the sequestration process for the removal of atmospheric CO₂. The conventional thermal analysis of synthetic nesquehonite proves that dehydration takes place in two steps at 157, 179°C and decarbonation at 416 and 487°C. Controlled rate thermal analysis shows the first dehydration step is isothermal and the second quasi-isothermal at 108 and 145°C. In the CRTA experiment carbon dioxide is evolved at 376°C. CRTA technology offers better resolution and a more detailed interpretation of the decomposition processes of magnesium carbonates such as nesquehonite via approaching equilibrium conditions of decomposition through the elimination of the slow transfer of heat to the sample as a controlling parameter on the process of decomposition. Constant-rate decomposition processes of non-isothermal nature reveal partial collapse of the nesquehonite structure.     

Synthesis and Crystal Structure of Nitrotriammine Complex of Nitrosoruthenium(II) [RuNO(NH<Subscript>3</Subscript>)<Subscript>3</Subscript>(NO<Subscript>2</Subscript>)(OH)]Cl·0.5H<Subscript>2</Subscript>O

Procedures for the synthesis of the [RuNO(NH_{3 3}(NO₂)(OH)]Cl·0.5H₂O complex have been developed. The compound was investigated by IR spectroscopy, and also by powder and single crystal X-ray diffraction. Crystal data for H₁₁CIN₅O_4.5Ru: a = 6.5752(7) Å, b = 11.0900(18) Å, c = 12.296(2) Å, ά = 79.692(13)°, β = 85.088(11)°, γ = 87.395(11)°, V = 878.5(2) ų, Z = 4, d _calc = 2.190 g/cm³, space group . The structure is formed by [RuNO(NH₃)₃(NO₂)(OH)]⁺] complex cations, Cl⁻ anions, and crystallization water molecules. The complex crystallizes as yellow transparent prisms belonging to the triclinic crystal system; it is soluble in water and insoluble in ethanol and acetone. The crystals are stable when kept in a closed beaker, but gradually degrade in dry air.Original Russian Text Copyright © 2004 by V. A. Emel’yanov, S. A. Gromilov, and I. A. Baidina__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 923–932, September–October, 2004.     

Reduction of Oxide Mixtures of (Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> + CuO) and (Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> + Co<Subscript>3</Subscript>O<Subscript>4</Subscript>) by Low-Temperature Hydrogen Plasma

The paper presents experimental results pertaining to the reduction of oxide mixtures namely (Fe₂O₃ + CuO) and (Fe₂O₃ + Co₃O₄), by low-temperature hydrogen plasma in a microwave hydrogen plasma set-up, at microwave power 750 W and hydrogen flow rate 2.5 × 10^?6 m³ s^?1. The objective was to examine the effect of addition of CuO or Co₃O₄, on the reduction of Fe₂O₃. In the case of the Fe₂O₃ and CuO mixture, oxides were reduced to form Fe and Cu metals. Enhancement of reduction of iron oxide was marginal. However, in the case of the Fe₂O₃ and Co₃O₄ mixture, FeCo alloy was formed within compositions of Fe₇₀Co₃₀, to Fe₃₀Co₇₀. Since the temperature was below 841 K, no FeO formed during reduction and the sequence of Fe₂O₃ reduction was found to be Fe₂O₃ → Fe₃O₄ → Fe. Reduction of Co₃O₄ preceded that of Fe₂O₃. In the beginning, the reduction of oxides led to the formation of Fe–Co alloy that was rich in Co. Later Fe continued to enter into the alloy phase through diffusion and homogenization. The lattice strain of the alloy as a function of its composition was measured. In the oxide mixture in which excessive amount of Co₃O₄ was present, all the Co formed after reduction could not form the alloy and part of it appeared as FCC Co metal. The crystallite size of the alloy was in the range of 22–30 nm. The crystal size of the Fe–Co alloy reduced with an increase in Co concentration.     

Synthesis,properties, and molecular and crystal structure of diantipyrylmethanium Bis(μ-tartrato)dihydroxydigermanate(IV) tetrahydrate (HDAm)<Subscript>2</Subscript>[Ge<Subscript>2</Subscript>(μ-L)<Subscript>2</Subscript>(OH)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The complex (HDam)₂[Ge₂(μ-L)₂(OH)₂] · 4H₂O (I) (H₄L is tartaric acid, Dam is diantipyrylmethane) was synthesized for the first time. The individual character and composition of I was established by elemental analysis and X-ray diffraction. The thermal stability of I was studied. The coordination sites of H₄L in the germanium complex were determined by IR spectroscopy. The structure of I was determined by X-ray crystallography. The crystals of I are triclinic: a = 9.3098(10) Å, b = 9.8088(10) Å, c = 17.6869(10) Å, α = 84.009(10)°, β = 77.926(10)°, γ = 67.088(5)°, V = 1454.3(2) ų, Z = 2, space group P \(\bar 1\), R = 0.0628 for 6343 reflections with I > 2σ(I). The compound is composed of the complex anions [Ge₂(μ-L)₂(OH)₂]^2?, the HDam⁺ cations, and crystal water molecules. In the dimeric anion, the metal atoms are bound to two completely deprotonated ligands L^4?. The latter are coordinated to the metal through the carboxyl (av. Ge-O, 1.911(6) Å) and hydroxyl (av. Ge-O, 1.768(6) Å) oxygen atoms. The coordination of each Ge atom is completed to trigonalbipyramidal by the O atom of the hydroxy ligand in the axial position (av. Ge-O, 1.748(7) Å). Both L^4? ligands are D isomers. In the crystal, the complex anions and crystal water molecules are combined by a system of hydrogen bonds.     

Platinum–Ruthenium Cluster Complexes from the Reaction of Ru<Subscript>3</Subscript>(CO)<Subscript>12</Subscript> with Pt(PBu<Superscript>t</Superscript><Subscript>3</Subscript>)<Subscript>2</Subscript>

Three new platinum–ruthenium complexes: Pt₃Ru₃(PBu^t ₃)₃(CO)₁₂, 8, Pt₅Ru₃(PBu^t ₃)₃(CO)₁₂, 9 and PtRu₃(PBu^t ₃)₂(CO)₈(μ₃-PBu^t)(μ-H)₂, 10 were obtained from the reaction of Ru₃(CO)₁₂ with Pt(PBu^t ₃)₂. Compound 8 was obtained from this reaction when conducted at 25 °C. Compounds 9 and 10 were obtained when the reaction was conducted at 68 °C. The structure of 8 consists of a central triangular cluster of three ruthenium atoms with one Pt(PBu^t ₃) group bridging each of the three Ru–Ru bonds. The structure of 9 consists of a capped pentagonal bipyramidal cluster of eight metal atoms that is formed formally by the addition of two platinum atoms to 8. The structure of 10 contains a triangular cluster of three ruthenium atoms with a Pt(PBu^t ₃) group bridging one of the Ru–Ru bonds. A t-butyl phosphido ligand formed by degradation of a molecule of PBu^t ₃ bridges the three ruthenium atoms. This report is dedicated to the memory of Professor F. A. Cotton for his many pioneering contributions to inorganic and metal cluster chemistry.     

Crystal structure and spectroscopic properties of ciprofloxacinium pentachloroantimonate(III) monohydrate (C<Subscript>17</Subscript>H<Subscript>19</Subscript>N<Subscript>3</Subscript>O<Subscript>3</Subscript>F)SbCl<Subscript>5</Subscript> · H<Subscript>2</Subscript>O

Synthesis, X-ray diffraction, IR and luminescence spectroscopic studies of the monohydrate of pentachloroantimonate(III) of doubly protonated ciprofloxacin (C₁₇H₁₉N₃O₃F)SbCl₅ · H₂O (I) were performed. The structure of I is formed by SbCl₆ octahedra combined into polymeric chains [SbCl₅] _n ^2n? through common vertices, ciprofloxacinium cations (CfH₃)²⁺, and water molecules linked by hydrogen bonds. CfH is protonated at the carbonyl oxygen atom and the terminal nitrogen atom of the piperazinyl group. The electronic and geometric aspects determining the luminescence properties of I and of related compounds are discussed.     

Synthesis and structure of a three-dimensional coordination polymer [Ag<Subscript>3</Subscript>hmt<Subscript>3</Subscript>(μ<Subscript>3</Subscript>-btc)]·5H<Subscript>2</Subscript>O

A new coordination polymer [Ag₃hmt₃(₃-btc)]·5H₂O (1 )(hmt = hexamethylenetetramine, btc = 1,3,5-benzenetricarboxyl)has been successfully synthesized. Crystal data: P2₁/a , a = 11.9906(2) Å, b = 17.3689(2) Å, c = 16.96100(10) Å, = 101.9820(14)°, V = 3455.40(7) ų, Z = 4, Dc = 2.002 mg/m³. In the hexagonal structure of the Ag-hmt unit, each Ag-hmt unit comprises three Ag atoms and three hmt ligands. The ₃-btc ligands bridge the adjacent two-dimensional honeycomb-like Ag-hmt layers to form three-dimensional networks. Structural analysis shows that hydrogen bonds play a key role for the structural stability of the compounds.Original Russian Text Copyright © 2004 by Shoubo Qin, Sheming Lu, Yanxiong Ke, Jianmin Li, Shuxi Zhou, Xintao Wu, and Wenxin DuTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 566–571, May–June 2004.     

Cationic (metallic) “Memory” in double condensed phosphates: Metals Ln-oxides Ln<Subscript>2</Subscript>O<Subscript>3</Subscript>-phosphates MLn(PO)<Subscript>3</Subscript>)<Subscript>4</Subscript> and MLnP<Subscript>4</Subscript>O<Subscript>12</Subscript>

The cationic networks that fix the distribution of cations in planar sections parallel to basis planes of the unit cell of crystal structures have been studied. Topologically identical cationic networks have been shown to be the carriers of deep structure-forming “memory” that successively relates the structures of rare earth metals (La ST) and oxides Ln₂O₃ (A-and B-Ln₂O₃ ST) to the structures of double condensed phosphates MLn(PO₃)₄ and MLnP₄O₁₂.