Investigation of the redox properties of polynuclear “ladder” complexes containing Cr,Mn, and Fe

The redox potentials of new Cr, Mn, and Fe polynuclear ladder complexes, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Fe(CO)₂(¹,⁵-C₅H₄)Mn(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Mn(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁶-Ph)Cr(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Fe(CO)₂CH₂Ph, (⁵-Cp)Fe(CO)₂(¹,⁶-CH₂Ph)Cr(CO)₃, were measured and the mechanism of their electrochemical oxidation and reduction was suggested. It was shown that the - or -bonds of the bridging ligand can be cleaved selectively by applying cathodic or anodic potentials, respectively. On the basis of the obtained electrochemical data, a mechanism is suggested for the rearrangement observed when the complexes are metallated by butyllithium.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 362–366, February, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No 94-03-08628a).     

Synthesis and structures of silicon-, germanium-, and tin-containing tungsten carbyne complexes (ButO)3W≡C—EPh3 and [(ButO)3W≡C]2EPh2 (E = Si,Ge, Sn)

New tungsten carbyne complexes (Bu^tO)₃WC—SiPh₃, [(Bu^tO)₃WC]₂SiPh₂, [(Bu^tO)₃WC]₂GePh₂, and [(Bu^tO)₃WC]₂SnPh₂ were prepared by the reactions of (Bu^t)₆W₂ with Ph₃SiCC—Pr or Ph₂E(CC—Pr)₂ (E = Si, Ge, Sn) in individual crystalline form in 48—80% yields. The structures of both the (Bu^tO)₃WC—GePh₃ and (Bu^tO)₃WC—SnPh₃ compounds synthesized earlier and the new complexes were established by X-ray diffraction analysis.     

Ethynylisopropylgermanes and Their Trimethylsilyl Derivatives

The reaction of ethynylmagnesium bromide with chloroisopropylgermanes (i-Pr_{4 - n} GeCl_{/sub> n} , n = 1-3) was used to prepare previously unknown ethynylisopropylgermanes i-Pr_{4 - n} Ge(CCH) _n (n = 1-3). The reaction of Me₃SiCCMgBr with i-PrGeCl₃ afforded i-Pr(Me₃SiCC)_{3 - n} GeCl _n (n = 1, 2). The reaction of the monochloride with BrMdCCH gave i-Pr(HCC)₂GeCCSiMe₃, while with the dichloride, i-Pr(HCC)·Ge(CSiMe₃)₂ formed. The latter compounds were obtained by independent synthesis from i-PrGe(CCH)₃, EtMgBr, and ClSiMe₃. The reaction of (bromomagnesioethynyl)triisopropylgermane with Me₃SiCl gave i-Pr₃GeCSiMe₃.     

Zwitterionic [(H3NCH2C≡CC≡CCH2NH3)]Cu2Cl4 π-Complex: Template Synthesis and Crystal Structure

Crystals of the [(H₃NCH₂CCCCCH₂NH₃)]Cu₂Cl₄ -complex, formed in the oxidative dimerization of propargylammonium cations, were obtained by ac electrochemical synthesis from CuCl₂ · 2H₂O and propargylammonium chloride ([CCCH₂NH₃]Cl) and studied by X-ray diffraction analysis (DARCh automated diffractometer, MoK radiation, /2 scan mode; 2275 reflections with F 4(F), R = 0.048). Crystals are monoclinic: space group B2/b, a = 19.591(6) Å, b = 7.299(3) Å, c = 8.636(3) Å, = 106.83(3)°, Z = 4. The structure consists of individual [(H₃NCH₂CCCCCH₂NH₃)]Cu₂Cl₄ moietes united through the elongated Cu···Cl contacts (2.827(5) Å) into chains oriented along the [010] direction. The bond of the centrosymmetric propargylammonium dimer is -coordintated by copper(I) atom and is elongated to 1.227(6) Å.     

Cyclosilethynes containing exocyclic cyclopentyl and cyclohexyl groups

The reaction of BrMgCCSiMe₂CCSiMe₂CCSiMe₂CCSiMe₂CCMgBr with chloro(cyclopentyl)(methyl)silane in a large excess of THF gave 1-cyclopentyl-1,4,4,7,7,10,10,13,13-nonamethyl-1,4,7,10, 13-pentasilacyclopentadeca-2,5,8,11,14-pentayne. Similarly, 1,10-di(cyclopentyl)- or 1,6-di(cyclopentylmethyl)-1,4,4,7,7,10,13,13,16,16-decamethyl-1,4,7,10,13,16-hexasilacyclooctadeca-2,5,8,11,14,17-hexaynes were synthesized from BrMgCCSiMe₂CCSiMe₂CCMgBr and dichloro(cyclopentyl)methylsilane or dichloro(cyclopentylmethyl)(methyl)silane. Condensation of Me₂Si(CCMgBr)₂ with dichloro(cyclohexyl)-methylsilane afforded 1,7-di(cyclohexyl)-1,4,4,7,10,10-hexamethyl-1,4,7,10-tetrasilacyclododeca-2,5,8,11-tetrayne.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1282–1284.Original Russian Text Copyright © 2004 by O. Yarosh, Zhilitskaya, N. Yarosh, Albanov, Klyba, Voronkov.This revised version was published online in April 2005 with a corrected cover date.     

Molecular properties of some new cyclic ethynylsilanes

Summary The question about conjugation between -CC- and -SiMe ₂- groups in [-CC-SiMe ₂-] _n withn=4 and 5 has been investigated by AM 1 calculations which show strong conjugation. In the structure determination (AM 1, X-ray) and in the Raman spectra no significant differences to normal values are observed. The NMR Si-Ccoupling constant and UV spectra are presented.This paper is dedicated to Professor Dr. mult. Victor Gutmann on the occasion of his 70th birthday with warmest personal wishes     

3-Phenoxy- and 3-phenylthio-1-propynyl substituted derivatives of silicon and germanium

Reactions of bromomagnesiopropargyl phenyl ethers and their isostmctural sulfides BrMgCCCH₂XPh (X = O, S) with MeVinSiCl₂, Me(CH₂Cl)SiCl₂, EtSiHCl₂, and Me₂SiHCl afforded the corresponding 3-phenoxy- and 3-phenylthio-1-propynyl substituted derivatives of silicon (PhXCH₂CC)₂SiRR¹ and PhXCH₂CCSiHMe₂ (X = O, S). Reactions of the above-mentioned Iotsitch reagents with GeCl₄ led to the corresponding germanium derivatives (PhXCH₂CC)₄Ge (X = O, S).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 511–513, March, 1994.     

Change of selectivity of butadiene oxidation due to zeolitic support for phosphorus-vanadium catalyst

The effect of the OH groups of the zeolites HY, HZSM-5 and HZSM-11 on the selective behavior of the supported active component P–V–O (P/V=1) in the oxidation of butadiene is characterized in detail and discussed. It was shown that the change in the selectivity was caused by the interaction of the pure component with the protondonor centres of zeolite: on this type of catalysts with the supported active component only furan and not maleic anhydride is formed as a product.

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OH- HY, HZSM-5 HZSM-11 P–V–O (P/V=1) . , - : , .

     

New cobalt trimethylacetate complexes with pyridine

The reaction of the tetranuclear trimethylacetate complex Co₄(₃-OH)₂(-OOCCMe₃)₄(²-OOCCMe₃)₂(EtOH)₆ with pyridine in acetonitrile was studied. Two new compounds, viz., the hexanuclear cobalt(ii) complex Co₆py₄(₃-OH)₂(-OOCCMe₃)₁₀ (25% yield) and the unusual ionic compound [Co₃py₃(₃-O)(-OOCCMe₃)₆]⁺[Co₄py(₄-O)(-OOCCMe₃)₇]^– (5% yield), were prepared. The structures of the new compounds were established by X-ray diffraction analysis.     

Neue Reagentien zum papierchromatographischen Nachweis von Aminosäuren, 3. Mitt.: Reaktionen des 1,8-Trimethylenchinisatins mit primären Aminoverbindungen

Zusammenfassung 1,8-Trimethylenchinisatin-hydrat (TMCH) reagiert mit Aminosäuren zum farblosen Bis-(2-oxo-4-hydroxy-1,8-trimethylen-1,2-dihydro-3-chinolinyl)-amin (2). Da2 bei der Dehydrierung in das Farbsalz5 übergeht, welches eine dem Ruhemann-Purpur analoge Struktur aufweist, ergeben sich neuartige Aspekte zur Deutung des Mechanismus der Ninhydrin-Reaktion.

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1.8-Trimethylenequinisatin hydrate (TMCH) reacts with amino acids yielding the colorless bis-(2-oxo-4-hydroxy-1.8-trimethylene-1.2-dihydro-3-quinolyl)-amine (2). Upon dehydrogenation of2 the dye salt5 is obtained. Because of the close relationship between5 and Ruhemann's purple a re-interpretation of the mechanism of the ninhydrin reaction could be made.

     

Intensity of the η(C≡C) Bands in the IR Spectra of Acetylene Derivatives and σR 0 Constants of Organosilicon,Organogermanium, and Organotin Substituents

The integral absorptivities of shape-characteristic (CC) bands in the IR spectra of 66 acetylene derivatives RCCX (R = H, Me₃M; X are inorganic and organic substituents) are related by a common linear equation to the _R ⁰ constants of the R and X substituents. The _R R⁰ constants of 10 Alk₃M substituents were calculated. The _R ⁰, _R , and _R ⁺ constants of Me₃M substituents were analyzed. The positive _R ⁰ values (0.12, 0.06, and 0.04 for R = Si, Ge, and Sn, respectively) suggest that in the ground electronic state of Me₃MCCX molecules the resonance acceptor effect of the Me₃M substituents (d, conjugation) prevails over donor (, conjugation). The first effect attenuates and the second enhances as the atomic number of M increases.     

The substitution chemistry of RuCp* (temeda)Cl

Summary Halide abstraction from RuCp*(tmeda)Cl (1,tmeda=Me₂NCH₂CH₂NMe₂) with NaBPh₄ in CH₂Cl₂ leads to the formation of the sandwich complex RuCp*(⁶-C₆H₅BPh₃) (2). In the presence of CH₃CN (1 equiv.) and CO, however, the cationic complexes [RuCp*(tmeda)(CH₃CN)]⁺ (3) and [RuCp*(temeda)(CO)]⁺ (5) are obtained. In CH₃CN,tmeda is also replaced giving [RuCp*(CH₃CN)₃]⁺ (4). Complex1 reacts readily with terminal acetylenes HCCR, the products depending on the nature ofR (Ph, SiMe₃,n-Bu, COOEt). Thus, withR=Ph the ruthenacyclopentatriene complex RuCp*(,-C₄Ph₂H₂)Cl (6), withR=SiMe₃ the cyclobutadiene complex Ru(Cp*)(⁴-C₄H₂(1,2-SiMe₃)₂)Cl (7), and withR=n-Bu and COOEt the binuclear complexes (Cp*)RuCl₂(²:⁴-₂-C₄H₂(1,3-R)₂)Ru(Cp*) (8,9) are obtained. Furthermore, with diethyl maleate in the presence of 1 equiv. of LiCl,1 transforms into the new anionic complex Li[Ru(Cp*) (²-C₂H₂(COOEt)₂)Cl₂] (10). X-ray structures of2,3,4,7, and10 are included.

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Substitutionsreaktionen von RuCp*(tmeda)Cl

Zusammenfassung Chloridabspaltung von RuCp*(tmeda)Cl (1,tmeda=Me₂NCH₂CH₂NMe₂) mittels NaBPh₄ in CH₂Cl₂ führt zur Bildung des Halbsandwich-Komplexes RuCp*(⁶-C₆H₅BPh₃) (2), während in Gegenwart von CH₃CN oder CO die beiden kationischen Verbindungen [RuCp*(tmeda)(CH₃CN)]⁺ (3) und [RuCp*(tmeda)(CO)]⁺ (5) entstehen. In CH₃CN als Lösungsmittel wird sogartmeda unter Bildung von [RuCp*(CH₃CN)₃]⁺ (4) verdrängt. Komplex1 reagiert sehr leicht mit terminalen Alkinen HCCR, wobei die Produkte stark von der Natur des SubstituentenR (Ph, SiMe₃,n-Bu, COOEt) abhängen. Im Fall vonR=Ph entsteht der Ruthenacyclopentatrien-Komplex RuCp*(-C₄Ph₂H₂)Cl (6), mitR=SiMe₃ der Cyclobutadien-Komplex Ru(Cp*)(⁴-C₄H₂(1,2-SiMe₃)₂)Cl (7), und im Fall vonR=n-Bu und COOEt bilden sich die binuklearen Komplexe (Cp*)RuCl₂(²:⁴-₂-C₄H₂(1,3-R)₂)Ru(Cp*) (8,9). Überdies reagiert1 mit Maleinsäurediethylester in Gegenwart von LiCl zum neuen anionischen Komplex Li[Ru(Cp*) (²-C₂H₂(COOEt)₂)Cl₂] (10). Von2,3,4,7 und10 wurden die Kristallstrukturen bestimmt.

     

Self-Consistent Calculation of Activity Coefficients and the Diffusion Layer Capacitance in Asymmetric Electrolytes

It is shown that substituting activities of individual ions for their concentrations in the equation for the ionic strength of solution substantially extends application of the first approximation of the Debye–Hückel theory for electrolytes of different valence. The obtained relationship predicts a changeover from the square root law in the charge region where the average distance between ions lis smaller than the ionic-atmosphere thickness 1/, to the cube root law, at l> 1/. The increasing deviation from experimental data upon going from LaCl₃solutions to La₂(SO₄)₃is attributed to the formation of ionic pairs LaSO₄ ⁺.     

Reactions of the dinitrogen complextrans-[ReCl(N2)(dppe)2] with thiolate compounds and with carbon bisulphide

Summary The complextrans-[ReCl(N₂)(dppe)₂], (1) reacts with the thiolate salts Li[SC₆H₄Me-4], Tl[SC₆H₄Me-4] and [Pb(SBu-t)₂] to yield [ReCl(SC₆H₄Me-4)(dppe)₂], [Re(SC₆H₄Me-4) (dppe)₂] and [{ReO(dppe)}₂(-Cl)(-S)(-SBu-t)] (tentative formulation), respectively. The [ReCl(²-CS₂)(dppe)₂] complex appears to be formed by reaction of (1) with CS₂.     

Reaction of the Hexa-1,3,5-triyne Me3SiC≡CC≡CC≡CSiMe3 with Ru4(CO)13(μ 3-PPh): Parallels with the Chemistry of Alkynes and Diynes

Reaction of Ru₄(CO)₁₃(₃-PPh) (1) with the 1,3,5-hexatriyne Me₃SiCCCCC CSiMe₃ under mild thermal conditions affords initially Ru₄(CO)₁₀(-CO)₂{₄-¹,¹,²-P(Ph)C(CCSiMe₃)C(CCSiMe₃) (2), via the facile formation of a P–C bond in a manner similar to that demonstrated previously with alkynes and diynes. The 62-CVE cluster 2 readily decarbonylates to give crystallographically characterised Ru₄(CO)₁₀(-CO)(₄-PPh){₄-¹,¹,²,²-Me₃SiCCC₂CCSiMe₃} (3). Attempts to further incorporate the pendant alkyne moieties in 3 into the Ru₄ coordination environment were partially successful with Ru₄(CO)₁₀(₄-PPh)(₄-¹,¹,³,³-RC₄R') (4, R/R'=SiMe₃/CCSiMe₃) being formed as a minor product together with the unusual toluene coordinated species Ru₄(CO)₇(⁶-C₆H₅Me)(₄-PPh)(₄-¹,¹,³,³-Me₃SiC₄CCSiMe₄) (5). Cluster 3 reacts with an excess of Me₃SiCCCCCCSiMe₃ to give the open chain cluster Ru₄(CO)₉(₃-PPh){₄-²,²,⁴,⁴,-C₄(CCSiMe₃)(SiMe₃)C₄(CCSiMe₃)₃} (6).     

Charge control of phenol complexation with unsaturated compounds containing group IVB organometallic substituents. Interpretation of NMR spectra of acetylenic derivatives

²⁹Si and ¹¹⁹Sn chemical shifts in the NMR spectra of acetylenic derivatives Me₃ECCX (E = Si or Sn; X — organic substituents) and shifts of frequencies () of stretching vibrations of OH groups in the IR spectra of phenol when hydrogen-bonded to these compounds have been analyzed. In each of two series (E = Si or Sn), the and values are connected by a linear relationship; this indicates that there is virtually no effect of the magnetic anisotropy of the X substituents on the chemical shifts. It has been established that the shifts of the frequencies and the ²⁹Si and ¹¹⁹Sn chemical shifts are the relative characteristics of the effective negative charge on the carbon atoms of the triple bond in Me₃ECCX compounds.For the previous communication of this series, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2069–2073, December, 1993.     

The reactions of phenylacetylene with naphthalene complexes of europium and ytterbium. Molecular structure of [IYbC≡CPh(DME)2]2

Reactions of naphthaleneeuropium and naphthaleneytterbium, C₁₀H₈Ln(DME) (Ln = Eu or Yb), with phenylacetylene are accompanied by the formation of the C-C bond and yield the complexes of composition Ph₂C₄H₂Ln(DME)₂. Hydrolysis of the Ph₂C₄H₂Ln(DME)₂ complexes affords a mixture of isomers of 1,4-diphenyl-1,3-butadiene. Reactions of C₁₀H₈[LnI(DME)₂]₂ with PhCCH yield mixed iodine-ethynyl complexes [ILn(-CCPh)(DME)₂]₂. According to the data of X-ray diffraction analysis, the ytterbium complex consists of two YbI(DME)₂ units bonded through two bridging CCPh groups. The crystals of this complex belong to the space groupP2₁/c. The central cyclic Yb-C-Yb-C fragment is planar; the C(I)-Yb(I)-C(I) angle is 86.4(3)°. The Yb-C bond lengths are 2.584(8) and 2.603(9) Å.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2101–2104, August, 1996.     

Synthesis of dicationic triple-decker complexes with a central B-cyclohexyl-substituted borole ligand

Stacking reactions of the dicationic fragments [LM]²⁺ (LM = (-C₆H₆)Ru, (-C₆H₃Me₃)Ru, or (-C₅Me₅)Rh) with the complex (-C₅H₅)Co(-C₄H₄BCy) (Cy = cyclo-C₆H₁₁) afforded new dicationic 30-electron triple-decker complexes [(-C₅H₅)Co(-:-C₄H₄BCy)ML](BF₄)₂ containing a cyclohexyl-substituted borole ligand in the central position.     

Synthesis and protonation of an OS3(μ-H)(CO)10(μ-σ,η2-C≡CCMe2OMe) cluster

Triosmium cluster Os₃(-H)(CO)₁₀(--²-CCC Me₂OMe) (1) was obtained by treating OS₃(-H)(-Cl)(CO)₁₀ with LiCCCMe₂OMe. The reaction of cluster1 with HBF₄ · Et₂O at –60 °C leads to the cationic complex [Os₃(-H)(CO)₁₀(-,,²-C=C=C Me₂)]⁺BF₄ ^– (2) with an allenylidene ligand. The^s1H and¹³C NMR spectra of complex2 reveal the temperature dependence caused by migration of hydrocarbon and carbonyl ligands. Thermodynamic parameters were obtained for be exchange process of the allenylidene ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp, 2990–2992, December, 1996.     

Investigation of the effects of diethylene glycol on the hydration of C3S and C3A pastes

The effects of diethylene glycol on the hydration characteristics of tricalcium silicate and tricalcium aluminate pastes were studied. Diethylene glycol acts as a retarder in the hydration of C₃S, and as an accelerator in the hydration of C₃A. The amount of Ca(OH)₂ found in pastes of C₃S treated with diethylene glycol was lower, the induction period increased and the formation of hydrates was retarded. For C₃A pastes, hydration in the presence of diethylene glycol accelerated the formation of the hexagonal aluminate hydrates and promoted the conversion to the cubic form.

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Zusammenfassung Der Einfluss von Diethylenglykol auf die Hydratation von Tricalciumsilicat- (C₃S) und Tricalciumaluminat- (C₃A) -Pasten wurde untersucht. Diethylenglykol verzögert die Hydratation des C₃S und beschleunigt die des C₃A.In C₃S-Proben, die mit Diethylenglykol hydratisiert wurden, ist der Gehalt an Ca(OH)₂ geringer, die Induktionsperiode länger und die Bildung von Hydraten verzögert. In C₃A-Pasten wird in Gegenwart von Diethylenglykol die Bildung des hexagonalen Calciumaluminathydrats beschleunigt und seine Umwandlung in die kubische Form begünstigt.

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