Recent Chemistry Based on the [RuCp(CH3CN)3]+ Cation: Reappraisalof an Old Precursor

Summary.  This article gives an overview of recent chemistry based on the tris-acetonitrile complex [RuCp(CH₃CN)₃]⁺. Due to the labile nature of the CH₃CN ligands, substitution reactions are a dominant feature of this complex. Important derivatives are the highly reactive complexes [RuCp(PR ₃)(CH₃CN)₂]⁺ which are a source of the 14e⁻ fragment [RuCp(PR ₃)]⁺. These species are catalytically active in the redox isomerization of allyl alcohols to give aldehydes and ketones. Furthermore, the cationic complex [RuCp(κ¹(P),η²-PPh₂CH₂CH₂CH*CH₂)(CH₃CN)]PF₆ derived from the reaction of [RuCp(CH₃CN)₃]⁺ with PPh₂CH₂CH₂CH*CH₂ is a model compound for studying coupling reactions of olefins and acetylenes. In addition, [RuCp(CH₃CN)₃]⁺ is a valuable precursor for the synthesis of configurationally stable chiral three-legged piano-stool ruthenium complexes. These are currently being intensively investigated as Lewis acid catalysts in asymmetric synthesis. Received May 31, 2000. Accepted June 13, 2000     

Selective formation of trans and cis(CH3CN) isomers of [Ru(bpy)(CO)2(CH3CN)2] (bpy=2,2-bipyridine) from [Ru(CO)2(CH3CN)3]2(PF6)2 using an electrochemical oxidation step

The selective in situ synthesis of trans and cis(CH₃CN)-[Ru(bpy)(CO)₂ (CH₃CN)₂]²⁺ isomers from the same [Ru(CO)₂ (CH₃CN)₃]₂²⁺ dimer precursor but using either an electrochemical-chemical or chemical-electrochemical process is described.     

三氮唑配合物[Cu2(CH3COO)4(C4H8N4)2]·2CH3CN的合成及晶体结构

Cu(CH₃COO)₂和4-氨基-3,5-二甲基-1,2,4-三氮唑反应制得标题化合物的单晶[Cu₂(CH₃COO)₄(C₄H₈N₄)₂]·2CH₃CN。晶体属三斜晶系,空间群,a=8.266(2),b=8.585(2),c=10.741(2)Å,α=75.58(3),β=88.     

配合物[La(pic)3(phen)2]·CH3CN的合成及晶体结构

The Lanthanum picrate complex with 1,10-phenanthroline was synthesized, whose chemical formula can be written in [La(pic)₃(phen)₂]·CH₃CN. The crystal Xray diffraction analysis shows that crystal belongs to monoclinic with space group P2₁/a and unit cell parameters:a=17.072(4),b=16.083(4),c=17.789(4),β=106.34(2)°,V=4687(4)³, Z=4,Dc=1.735g·cm³, μ=10.106cm¹,F(000)=2448,R=0.0589,Rw=0.0589. The coordination number of La³⁺ is nine. Acetonitrile, a solvent molecule is not coordinated. Between three Pic ligands, that possesses 2 bidentate forms six member ring with La. The other is unidentate ligand. As usually, phen is bidentate ligand.     

Study on the covalence of Cu and chemical bonding in an inorganic fullerene-like molecule, [CuCl]20[Cp*FeP5]12 [Cu-(CH3CN)+2Cl-]5, by a density functional approach

The electronic structure and chemical bonding in a recently synthesized inorganic fullerene-like molecule, [CuCl]₂₀[Cp*FeP₅]₁₂[Cu-(CH₃CN) ⁺ ₂Cl⁻]₅ has been studied by a density functional approach. Geometrical optimization of the three basic structural units of the molecule is performed with Amsterdam Density Functional Program. The results are in agreement with the experiment. Localized MO’s obtained by Boys-Foster method give a clear picture of the chemical bonding in this molecule. The reason why CuCl can react with Cp*FeP₅ in solvent CH₃CN to form the fullerene-like molecule is explained in terms of the soft-hard Lewis acid base theory and a new concept of covalence.     

Reaction of [CpRu(CH3CN)3]PF6 with bidentate ligands: structural characterization of [{CpRu(CH3CN)2}2(μ-η-dppe)](PF6)2 [dppe=1,2-bis(diphenylphosphino)ethane]

The reaction of [CpRu(CH₃CN)₃]PF₆ with the bidentate ligands L-L=1,2-bis(diphenylphosphino)ethane, dppe, and (1-diphenylarsino-2-diphenylphosphino)ethane, dpadppe, affords mononuclear or dinuclear complexes of formula [CpRu(η²-L-L)(CH₃CN)]PF₆, [{CpRu(CH₃CN)₂}₂(μ-η^1:1-L-L)](PF₆)₂ and [{CpRu(CH₃CN)}₂(μ-η^1:1-L-L)₂](PF₆)₂ (L-L=dppe, dpadppe). All of the compounds are characterized by microanalysis and NMR [¹H and ³¹P{¹H}] spectroscopy. The crystal structure of [{CpRu(CH₃CN)₂}₂(μ-η^1:1-dppe)](PF₆)₂ has been determined by X-ray diffraction analysis. The complex exhibits a dppe ligand bridging two CpRu(CH₃CN)₂ fragments.     

Synthesis, DNA-binding and photocleavage studies of ruthenium(Ⅱ) complexes [Ru(btz)_3]~(2+) and [Ru(btz)(dppz)_2]~(2+)

Two new ruthenium(Ⅱ) complexes, [Ru(btz)3](ClO4)2 (1) and [Ru(btz)(dppz)2](ClO4)2 (2) (btz = 4,4′-bithi-azole, dppz = dipyrido[3,2-a:2′,3′-c]phenazine), have been synthesized and characterized by elemental analysis, 1H NMR, ES-MS and X-ray crystallography. The DNA binding behaviors of two complexes have been studied by spectroscopic and viscosity measurements. The results suggest that complex 1 binds to CT-DNA via an electrostatic mode, while complex 2 via an intercalative mode. Under irradiation at 365 nm,...     

[Fe(phen)3]2+ aquation in aqueous polyacrylamide solution

The aquation of tris(1, 10-phenanthroline) iron(II) has been studied in aqueous polyacrylamide solutions. The rate increases up to 2.8 times at low polymer concentrations, and subsequently decreases. These effects are attributed to changes in the local water activity in the region of the complex.

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(1, 10-) (II) . 2,8 , . .

     

Structure and bonding in a series of cyano complexes: RuCp(PPh3) 2CN, [RuCp(PPh3) 2(CNH)]CF3SO3, and H-bridged [Ru2(Cp) 2(PPh3) 4CNHNC]CF3SO3

The three title cyanoruthenium complexes have been characterized by means of X-ray diffraction analysis, IR and NMR solution spectroscopies, as well as extended Hückel molecular orbital calculations examining the properties of the cyanide fragment changing with complexation and with the co-ligands Cp and PPh₃. Explanations are given for crystallographic results of the C-N bond shortening upon complexation, the supershort (2.573 Å) bond length of N(H) N in the bridged complex, as well as the Ru-C-N and C-N-H-N-C bendings. Although the crystallographically found asymmetry of coordinated Cp is not significant, the MO calculations suggest a distorted endocyclic bond-length pattern indicative of the relative importance of σ and π bonding in the metalcyclopentadienyl interactions.     

Lumineszenz von [Co(CN)6]3-[Rh(CH)6]3-[Ir(CN)6]3-mit verschiedenen Gegenionen

Ohne Zusammenfassung     

微量热法研究 [Cu(phen)2]2+、[Cu(bpy)2]2+与DNA的作用

用微量热法对菲咯啉合铜([Cu(phen)     

Formation of a Hydroxo-bridged Dinuclear Ru(III)/Ru(III) Complex from N-Methylimidazole and [Ru Cp(CH 3CN) 3] +

The reaction of [RuCp(CH₃CN)₃]PF₆ with 1 equiv of N-Me-imidazole results in the quantitative formation of [RuCp(¹N-N-Me-imidazole)(CH₃CN)₂]PF₆ (1) featuring a ¹N rather than a ¹C bound N-Me-imidazole ligand. According to DFT/B3LYP calculations, ¹N coordination of N-Me-imidazole is preferred over ¹C coordination by 25.5kJ/mol. Upon exposure to air 1 reacts with oxygen and water to afford the novel hydroxo-bridged dinuclear complex of [Ru₂Cp₂(¹N-N-Me-imidazole)₂(-OH)₂](PF₆)₂ (2) featuring a metal-metal single bond. The dimeric nature of 2 was confirmed by a single-crystal X-ray structure analysis.     

Actinide-centered cyclometalation chemistry. An unusually distorted thorium bishydrocarbyl: Thp[η5-(CH3)5C5]2CH2Si(CH3)3]2

The crystal and molecular structure of the complex Th[η⁵-(CH₃)₅C₅]₂[CH₂-Si(CH₃)₃]₂, which undergoes facile intramolecular cyclometalation to the thoracyclobutane Th[η⁵-(CH₃)₅C₅]₂(CH₂)₂Si(CH₃)₂, is reported. While the Th[η⁵-(CH₃)₅C₅]₂ ligation is unexceptional, the Th[CH₂Si(CH₃)₃]₂ fragment is highly unsymmetrical having Th-C (corresponding angle Th-C-Si) 2.51(1) Å (132.0(6)°) and 2.46(1) Å (148.0(7)°). This conformation, which appears to result from severe intramolecular non-bonded contacts, allows a methyl hydrogen atom of one CH₂Si(CH₃)₃ ligand to approach within ca. 2.3 Å of the α-carbon atom of the other CH₂Si(CH₃)₃ ligand.     

铜氨络离子的形成和空间构型的探究

基于化学平衡的原理,通过简单的计算解释了氢氧化铜溶于氨水的反应机理,同时基于价键理论和Jahn-Teller效应来阐述铜氨络离子以及其他铜离子配合物的形成过程.     

Synthesis and x-ray crystal structure of [PPN]+2[RuIr4(CO)9(μ2-CO)6]2-

The dianion [RuIr₄(CO)₁₅]^2- has been obtained by reductive carbonylation of mixtures of Ir₄(CO)₁₂ and RuCl₃ · χ H²O, and the bis(triphenylphosphine)-iminium salt has been characterized by single-crystal X-ray diffraction techniques. Crystal data: [((C₆H₅)₃P)₂N]₂[RuIr₄(CO)₁₅], space group P$\text{1}$ (Z  2), a  11.425(3), b  14.141(2), c  25.979(5) Å, α  84.55(1), β  83.53(2), γ  80.71(2)°. The mixed-metal cluster has a structure with an elongated trigonal bipyramidal array of metal atoms in which Ru occupies an apical position. The anion is unstable in vacuum or in an N₂ atmosphere yielding predominantly another mixed-metal species which is not as yet fully characterized. Upon reexposure to CO, this latter species is converted back to [RuIr₄(CO)₁₅]^2-, plus additional products.     

New Bimetallic Ni–Rh Carbonyl Clusters: Synthesis and X-ray Structure of the [Ni7Rh3(CO)18]3?, [Ni3Rh3(CO)13]3? and [NiRh8(CO)19]2? Cluster Anions

The reaction of the [Ni₆(CO)₁₂]²⁻ dianion with [Rh(COD)Cl]₂ (COD = cyclooctadiene) in acetone affords a mixture of bimetallic Ni–Rh clusters, mainly consisting of the new [Ni₇Rh₃(CO)₁₈]³⁻ and [Ni₈Rh(CO)₁₈]³⁻ trianions. A study of the reactivity of [Ni₇Rh₃(CO)₁₈]³⁻ led to isolation of the new [Ni₃Rh₃(CO)₁₃]³⁻ and [NiRh₈(CO)₁₉]²⁻ anions. All these new bimetallic Ni–Rh carbonyl clusters have been isolated in the solid state as tetrasubstituted ammonium salts and have been characterised by elemental analysis, X-ray diffraction studies, ESI-MS and electrochemistry. The unit cell of the [NEt₄]₃[Ni₇Rh₃(CO)₁₈] salt contains two orientationally-disordered ν₂-tetrahedral [Ni₇Rh₃(CO)₁₈]³⁻ trianions with occupancy factors of 0.75 and 0.25. Besides, their inner Ni₃Rh₃ octahedral moieties show two cis sites purely occupied by Rh atoms, two trans sites purely occupied by Ni atoms and the remaining two cis sites are disordered Ni and Rh sites with respective occupancy fraction of 0.5. At difference from the parent [Ni₇Rh₃(CO)₁₈]³⁻, the octahedral [Ni₃Rh₃(CO)₁₃]³⁻ displays an ordered distribution of Ni and Rh atoms in two staggered triangles. The [NiRh₈(CO)₁₉]²⁻ dianion adopts an isomeric metal frame with respect to that of the [PtRh₈(CO)₁₉]²⁻ congener. As a fallout of this work, new high-yield synthesis of the known [Ni₆Rh₃(CO)₁₇]³⁻ and [Ni₆Rh₅(CO)₂₁]³⁻, as well as other currently-investigated bimetallic Ni–Rh clusters have been obtained.     

Aggregates of complexes [Sc(H2O)4(NCS)2]+ and [Sc(H2O)2(NCS)4]? with 18-crown-6

The compounds [Sc(H₂O)₄(NCS)₂][Sc(H₂O)₂(NCS)₄] ·2(18C6) (I) and [Sc(H₂O)₄(NCS)₂][Sc(H₂O)₂(NCS)₄] · 3(18C6) · H₂O (II) were synthesized and studied by X-ray diffraction analysis. It was found that the cations in the structures of compounds I and II form sandwiches [Sc(H₂O)₄(NCS)₂] · 2(18C6). In the case of I, the sandwiches are united by the [Sc(H₂O)₂(NCS)₄]⁻ anions into chains, while in compound II, the sandwiches and infinite chains of [Sc(H₂O)₂(NCS)₄] · 18C6 · H₂O are bonded by van der Waals contacts only. Original Russian Text ? A.B. Ilyukhin, S.P. Petrosyants, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 4, pp. 275–281.     

Spectroscopic characteristics of dimethylsulfoxide molecules coordinated to Mg2+ cation. structure of complexes [Mg(DMSO)i(CH3CN)6-i]2+ from the data of quantum-chemical calculations and IR spectra of Mg(ClO4)2-DMSO-CH3CN Solutions

By the DFT B3LYP/6-31G** method the geometry was optimized and IR spectra were calculated of complexes [Mg(DMSO) _i (CH₃CN)_6-i ]²⁺ (i = 1–6). The values of free energy ΔG in the reaction of ligands substitution in the coordination sphere of the cation were determined. A satisfactory agreement between experimental and calculated values of structural parameters and infrared spectra of free molecules and coordinated to the cation DMSO was obtained. The regularities in the changes of the spectroscopic and structural characteristics of [Mg(DMSO) _i (CH₃CN)_6-i ]²⁺ complexes at varying their composition were revealed. The frequencies and absolute integral intensities of DMSO bands in the IR spectra of pure liquid, solutions in acetonitrile, and in three-component solutions Mg(ClO₄)₂-DMSO-CH₃CN were measured. A correspondence between the calculated change of the frequency and absolute intensity of the IR bands v(C≡N), v(C-C), v(S=O), and v(SC) of the complexes and the corresponding values in the IR spectra of the solutions with different content of components of binary solvent was found.     

Multiparameter equations of state for siloxanes: [(CH3)3-Si-O1/2]2-[O-Si-(CH3)2]i=1,…,3, and [O-Si-(CH3)2]6

This article presents the continuation of the work on the development of technical equations of state for linear and cyclic siloxanes already documented in this journal. The fluids considered herewith are octamethyltrisiloxane (MDM, C₈H₂₄Si₃O₂), decamethyltetrasiloxane (MD₂M, C₁₀H₃₀Si₄O₃), dodecamethylpentasiloxane (MD₃M, C₁₂H₃₆Si₅O₄), dodecamethylcyclohexasiloxane (D₆, C₁₂H₃₆Si₆O₆). The 12-parameter functional form proposed by Span and Wagner has been selected because of its positive characteristics. Siloxanes are produced in bulk quantities and are mostly utilized in the cosmetics industry and, mixed, as high-temperature heat transfer fluids. Furthermore, they are used as working fluids in high-temperature organic Rankine cycle power plants. The available property measurements are carefully evaluated and selected for the optimization of equation of state parameters. For some of the fluids, experimental values are scarce, therefore ad hoc estimation methods have been used to supply more information to the procedure for the optimization of the parameters of the equation of state. In addition, saturated liquid density and vapor pressure measurements are correlated with the equations proposed by Daubert and Wagner–Ambrose, respectively, to provide short, simple, and accurate equations for the computation of these properties. The recently developed isobaric ideal-gas heat capacity correlation for the selected siloxanes is included in the thermodynamic models. The performance of the newly developed equations of state is tested by comparison with experimental data and also with predictions calculated with the Peng–Robinson–Stryjek–Vera cubic EoS, as this model was adopted in previous technical studies. The new thermodynamic models perform significantly better than cubic equations of state. T–s and P  – v$v$ diagrams for all the substances are also reported.     

Trimeric, Cyclic Dimethyltin-Containing Tungstophosphate [{(Sn(CH3)2)(Sn(CH3)2O)( A- PW9O34)}3]21?

The trimeric, cyclic dimethyltin-containing tungstophophate [{(Sn(CH₃)₂)(Sn(CH₃)₂O)(A-PW₉O₃₄)}₃]²¹⁻ (1) has been synthesized in aqueous acidic medium and characterized by IR, elemental analysis, electrochemistry, and FT-ICR MS. Single-crystal X-ray analysis was carried out on Cs₁₂Na₉[{(Sn(CH₃)₂)(Sn(CH₃)₂O)(A-PW₉O₃₄)}₃]·20H₂O (1a), which crystallizes in the trigonal system, space group R3, with a = b = 29.7445(7) ?, c = 15.5915(7) ? and Z = 3. Polyanion 1 is composed of three trilacunary (A-PW₉O₃₄) Keggin fragments that are linked on one side via three isolated dimethyltin groups and on the other side by a (Sn₃(CH₃)₆O₃) unit and three cesium ions, resulting in a cyclic assembly with C _3v symmetry. The discrete molecular, hybrid organic–inorganic 1 was synthesized by reaction of (CH₃)₂SnCl₂ with Na₉[A-PW₉O₃₄] in 0.5 M sodium acetate buffer (pH 4.8). Comparison of several characteristics of the cyclic voltammograms of 1 and (A-PW₉O₃₄)⁹⁻, including the potential location of their reduction peaks, the difference in their current intensities and their qualitative relative electron transfer speeds, supports the conclusion that the solid-state structure of 1 is retained in solution. The presence of (PW₉O₃₄)-based species in solutions of 1 was also confirmed by FT-ICR mass spectrometry. Dedicated to Professor Günter Schmid on the occasion of his 70th birthday.