Home About us Contact
|
Home About us Contact | ||
|
|
||
Cl Bond (cl + bond)
Selected AbstractsCatalytic C,C Coupling Reactions at Nickel by C,F Activation of a Pyrimidine in the Presence of a C,Cl Bond: The Crucial Role of Highly Reactive Fluoro Complexes.CHEMINFORM, Issue 48 2005Andreas Steffen Abstract For Abstract see ChemInform Abstract in Full Text. [source] Photoinduced Metalation of Nonactivated C,Cl Bonds with Samarium Diiodide: Synthesis of Alkenes with High (Z)-Selectivity Through ,-Elimination Reactions.CHEMINFORM, Issue 18 2006Jose M. Concellon Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] 16-Electron (Arene)ruthenium Complexes with Superbasic Bis(imidazolin-2-imine) Ligands and Their Use in Catalytic Transfer HydrogenationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 29-30 2009Thomas Glöge Abstract The ligands N,N, -bis(1,3,4,5-tetramethylimidazolin-2-ylidene)-1,2-ethanediamine (BLMe) and N,N, -bis(1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene)-1,2-ethanediamine(BLiPr) react with [(,5 -C5Me5)RuCl]4 to afford cationic 16-electron half-sandwich complexes [(,5 -C5Me5)Ru(BLR)]+ (R = Me, 3; R = iPr, 4), which resist coordination of the chloride counterion because of the strong electron-donating ability of the diimine ligands. Upon reaction with [(,6 -C6H6)RuCl2]2 or [(,6 -C10H14)RuCl2]2, these ligands stabilize dicationic 16-electron benzene and cymene complexes of the type [(,6 -C6H6)Ru(BLR)]2+ (R = Me, 5; R = iPr, 6) and [(,6 -C10H14)Ru(BLR)]2+ (R = Me, 7; R = iPr, 8). The X-ray crystal structure of [5]Cl2 reveals the absence of any direct Ru,Cl interaction, whereas a long Ru,Cl bond, supported by two CH···Cl hydrogen bonds, is observed for [(6)Cl]Cl in the solid state. Treatment of the dichlorides of 6 and 8 with NaBF4 affords [6](BF4)2 and [8](BF4)2, which are composed of individual dications and tetrafluoroborate ions with no direct Ru,F interaction. All complexes catalyze the transfer hydrogenation of acetophenone in boiling 2-propanol. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Do Metal,Metal Multiply-Bonded "Ligands" Have a trans Influence?EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 36 2008Magnetic Comparisons of Heterometallic CrCr···Co, MoMo···Co Interactions, Structural Abstract Reported here are two new compounds containing either a CrCr···Co [1, CrCrCo(dpa)4Cl2, dpa = 2,2,-dipyridylamide] or a MoMo···Co [2, MoMoCo(dpa)4Cl2] framework both having a multiply-bonded unit (CrCr in 1, MoMo in 2) in close proximity to the Co2+ ion and trans to a Co,Cl bond. Variable temperature magnetic susceptibility measurements reveal 1 to have a temperature-dependent spin equilibrium between a low-spin (S = 1/2) and high-spin (S = 3/2) state, whereas the Co2+ ion in 2 exists solely in its high-spin state. The crystal structures of 1 and 2 were determined. Variable temperature crystallographic data of 1 at 100 K and at room temperature reveal that the spin-transition affects not only the Co,ligand bond lengths but also the terminal Cr,ligand bond lengths. Whereas the Cr···Co distance becomes shorter by 0.13 Å in the low-spin form, the Co,Cldistance becomes longer by 0.2 Å. These observations,along with the crystal structure of 2, suggest that the multiply-bonded MM group has a trans influence on the Co2+ ion.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Dichloro[1,1,-(5,9-dithia-2,12-diazoniatrideca-1,12-diene-1,13-diyl)dinaphthalen-2-olato-,2O,O,]dimethyltin(IV) acetonitrile solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2003Stanley A. Bajue Reaction of the potentially hexadentate ligand 1,9-bis(2-hydroxy-1-naphthalenemethylimino)-3,7-dithianonane with dimethyltin chloride gave the title 1:1 adduct, in which the long ligand wraps around the SnCl2Me2 unit and in which the stereochemistry is fully trans. This compound crystallizes from acetonitrile as the 1:1 solvate [Sn(CH3)2(C29H30N2O2S2)Cl2]·C2H3N. During the reaction, the hydroxyl protons move to the N atoms. Most of the chemically equivalent bond lengths agree to within experimental uncertainty, but the Sn,Cl bond that is inside the ligand pocket is substantially longer than the Sn,Cl bond that points away from the long ligand [2.668,(1) versus 2.528,(1),Å]. The O,Sn,O angle is 166.0,(1)°. Comparison of the Sn,O, C,O and aryl C,C bond lengths with those of related compounds shows that the most important resonance forms for the Schiff base aryloxide ligand are double zwitterions, but that the uncharged resonance forms having carbonyl groups also contribute significantly. [source] CdBiO2Cl: synthesis and powder structure solutionACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2001Sergei D. Kirik The title compound, cadmium bismuth dioxide chloride, CdBiO2Cl, was obtained as a white powder by reaction of solid BiOCl with CdO at 973,K. Ab initio crystal structure determination was carried out using X-ray powder diffraction techniques, including direct methods for atom location and Rietveld fitting for the final refinement. Being monoclinic, the crystal structure can be related to tetragonal Sillen layered phases. The main structural elements present are CdBiO2+ pleated metal,oxygen layers alternating with Cl layers along the c axis, whereas along the b axis, all atoms are on mirror planes. The formation of a strong Cd,Cl bond draws the layers together, causing layer deformation and a monoclinic distortion in the layer arrangement. [source] cis -Dichloro(dimethyl sulfoxide- S)(2-methoxypyridine- N)platinum(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2000Georgia M. Arvanitis The title complex, [PtCl2(C6H7NO)(C2H6OS)], exhibits square-planar geometry. The plane of the pyridine ring makes a dihedral angle of 67.2,(3)° with the square plane of the metal center. The S,O bond is nearly aligned with the adjacent Pt,N bond, leaving the methyl groups of the dimethyl sulfoxide ligand to stagger the Pt,Cl bond. [source] Use of CsCl to Enhance the Glass Stability Range of Tellurite Glasses for Er3+ -Doped Optical Fiber DrawingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2007Carmen Rosa Eyzaguirre Tellurite glasses are important as a host of Er3+ ions because of their good solubility and because they present broadband optical gain compared with Er3+ -doped silica, with the potential to increase the bandwidth of communication systems. However, the small glass stability range (GSR) of tellurite glasses compromises the quality of the optical fibers. We show that the addition of CsCl to tellurite glasses can increase their GSR, making it easier to draw good-quality optical fibers. CsCl acts like a network modifier in glass systems, weakening the network by forming Te,Cl bonds. We show that the thermal expansion coefficient mismatch is in the right direction for optical fiber fabrication purposes and that the Bi2O3 content can be used to control the refractive index of clad and core glasses. Single-mode and multi-mode Er3+ -doped optical fibers were produced by the rod-in-tube method using highly homogeneous TeO2,ZnO,Li2O,Bi2O3,CsCl glasses. [source] [Ru(py)4Cl(NO)](PF6)2·0.5H2O: a model system for structural determination and ab initio calculations of photo-induced linkage NO isomersACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009Benoît Cormary Structure analysis of ground state (GS) and two light-induced (SI and SII) metastable linkage NO isomers of [Ru(py)4Cl(NO)](PF6)2·0.5H2O is presented. Illumination of the crystal by a laser with , = 473,nm at T = 80,K transfers around 92% of the NO ligands from Ru,N,O into the isomeric configuration Ru,O,N (SI). A subsequent irradiation with , = 980,nm generates about 48% of the side-on configuration (SII). Heating to temperatures above 200,K or irradiation with light in the red spectral range transfers both metastable isomers reversibly back to the GS. Photodifference maps clearly show the N,O configurations for both isomers and they could be used to find a proper starting model for subsequent refinements. Both metastable isomers have slightly but significantly different cell parameters with respect to GS. The main structural changes besides the Ru,O,N and linkage are shortenings of the trans Ru,Cl bonds and the equatorial Ru,N bonds. The experimental results are compared with solid-state calculations based on density functional theory (DFT), which reproduce the observed structures with high accuracy concerning bond lengths and angles. The problem of how the different occupancies of SI and GS could affect refinement results was solved by a simulation procedure using the DFT data as starting values. [source] Structural investigations of phosphorus,nitrogen compounds.ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3-2 2002A systematic study is presented on the products of aminolysis of N3P3Cl6 (1) and N3P3Ph2Cl4 (4) with dibenzylamine. Two series of mono- and disubstituted derivatives of compounds (1) and (4), namely N3P3Cl5[N(CH2Ph)2] (2) and N3P3Cl4[N(CH2Ph)2]2 (3) and N3P3Ph2Cl3[N(CH2Ph)2] (5) and N3P3Ph2Cl2[N(CH2Ph)2]2 (6) [where (2), (3), (5) and (6) are new structures], are investigated in order to determine whether steric or electronic effects prevail in the formation of dibenzylamino-substituted cyclophosphazenes. The influence of an electron-releasing group (i.e. phenyl) on the stereochemistry and degree of substitution of the product is analysed by comparison of the above two series. The difference in unsymmetrically substituted endocyclic P,N bond lengths, ,, is used as a measure of the degree of the electronic contribution, in combination with basicity constants, to quantify the degree of the electron-releasing capacity of the R group. In order to compare geminal versus non-geminal substitution, a difunctional secondary amine was used to form the compound N3P3Cl4[NMe(CH2)3NMe] (7) (a reinvestigation) for inclusion in this study. It is shown that electron-releasing groups have a greater effect on the lengthening of P,Cl bonds as opposed to endocyclic P,N bonds and that this effect is greater in the non-geminal PRCl case than for geminal PCl2. However, steric effects are shown to be dominant in the reactions of dibenzylamine with N3P3 derivatives, with a disposition to a trans stereochemistry in bisdibenzylamino derivatives. [source] | ||||||||||