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Coordination Behavior (coordination + behavior)
Selected AbstractsCoordination Behavior of Oxide Ions in Inorganic Solids.CHEMINFORM, Issue 39 2004Part 4. Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Variable Binding Modes of Phenylbis(pyrid-2-ylmethyl)phosphane and Bis(pyrid-2-ylmethyl) Phenylphosphonite with AgI and CuIEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 20 2009Fernando Hung-Low Abstract A series of new bridging phosphane and phosphonite structures forming three- and six-membered rings with the metal centers were synthesized and characterized. The resulting compounds of phenylbis(pyrid-2-ylmethyl)phosphane (1) with the silver(I) salts of trifluoroacetate (tfa,), tetrafluoroborate (BF4,), and trifluoromethanesulfonate (OTf,), and copper tetrakis(acetonitrile) hexafluorophosphate (PF6,) shows the flexibility of the ligand by displaying different coordination modes associated with the electronic and structural characteristics of the corresponding anion. Accordingly, ligand 1 in these complexes displays two different binding modes. With Agtfa and AgBF4 compounds 3 and 4 are obtained where the ligand chelates to two silver atoms that exhibit normalAg,Ag contacts in the range of 2.9 Å. When AgOTf or Cu(NCCH3)4PF6 are used, one molecule of 1 bridges the metal centers through a phosphorus atom while another is terminally bound. This induces short M,M distances of 2.6871 and 2.568 Å for 5 and 6, respectively. Similarly, the coordination behavior of the heterofunctional bis(pyrid-2-ylmethyl) phenylphosphonite ligand (2) is reported with Cu(NCCH3)4PF6 (7) and AgBF4 (8) to form two novel discrete molecules. In these complexes 2 coordinates through the P and N atoms, with the difference that in 7 the O atom of one of the carbinol arms is also bound to the Cu. Elemental analysis, variable-temperature multinuclear NMR spectroscopy, single-crystal X-ray diffraction, and low-temperature luminescence studies were carried out to fully characterize the compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Surprising Coordination Geometry Differences in CeIV - and PuIV -Maltol Complexes,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2008Géza Szigethy Abstract As part of a study to characterize the detailed coordination behavior of PuIV, single-crystal X-ray diffraction structures have been determined for PuIV and CeIV complexes with the naturally occurring ligand maltol (3-hydroxy-2-methylpyran-4-one) and its derivative bromomaltol (5-bromo-3-hydroxy-2-methylpyran-4-one). Although CeIV is generally accepted as a structural analog for PuIV, and the maltol complexes of these two metals are isostructural, the corresponding bromomaltol complexes are strikingly different with respect to ligand orientation about the metal ion: All complexes exhibit trigonal dodecahedral coordination geometry but the CeIV,bromomaltol complex displays an uncommon ligand arrangement not found in the PuIV complex.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Complexation of 2,6-Bis(3-pyrazolyl)pyridine,Bis(thiocyanato)iron(II) with a Bridging 4,4,-Bipyridine: A New Example of a Dinuclear Spin Crossover ComplexEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2008Dalila Fedaoui Abstract Investigation of the coordination behavior of 2,6-bis(3-pyrazolyl)pyridine,bis(thiocyanato)iron(II) towards bridging ligands led to the discovery of a novel dinuclear complex showing spin-crossover. Chemical and structural characterization and a first report of physical properties are presented.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Anomalous concentration dependence of the coordination behavior of Cl, ion to Ln3+ ion (Ln3+ = rare-earth ion) in anhydrous LnCl3 alcohol solutionsJOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2007Y. Yoshimura Abstract Raman spectroscopic measurements were carried out for the anhydrous LnCl3·20ROH·XLiCl solutions (Ln3+ = La3+, Lu3+, X = 0,3; ROH = MeOH, EtOH, n -PrOH) in the liquid state. The salt concentration (X) dependence of the wavenumber for the Ln,Cl stretching Raman band (,Ln,Cl) is examined in conjunction with the formation of chloro-rare-earth complexes. We have obtained very intriguing results including the fact that the chloro complexations of the middle rare-earth ions (e.g. gadolinium, holmium ions, etc.) in the MeOH and EtOH solutions show peculiar behavior with regard to the salt concentration dependence: the ,Ln,Cl wavenumber increases with the increasing chloride concentration. However, the ,Ln,Cl wavenumbers of the light and heavy rare-earth (e.g. lanthanum, lutetium, etc.) salt solutions show normal behavior; i.e. ,Ln,Cl decreases with the increasing chloride concentration. On the other hand, in the n -PrOH solutions, the ,Ln,Cl frequency in the solutions of all the rare-earth elements exhibits a normal behavior. We now present a possible mechanism for this anomalous concentration dependence of coordination of Cl, ions to Ln3+ ions in anhydrous LnCl3 alcohol solutions. Copyright © 2007 John Wiley & Sons, Ltd. [source] Polymer Complexes: supramolecular assemblies and structures of poly[N -(2,-pyridyl)propenamide] complexesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2004A. T. A. Mubarak Abstract A number of new polymer complexes of palladium(II), platinum(II) and copper(II) containing homopolymer (N -(2,-pyridyl)propenamide; APH) and various anions (Cl,, Br,, I, or NO3,) have been synthesized and characterized by elemental analyses, magnetic susceptibility, electron paramagnetic resonance, IR and reflectance spectral measurements. The homopolymer shows three types of coordination behavior. In the mononuclear polymer complexes 1,6 and 9 it acts as a neutral bidentate ligand chelated through the pyridine-nitrogen and amide-oxygen atoms, whereas in the square-planar [Pd(APH)2X2] (X = Cl, Br) unidentate APH is coordinated through the pyridine-nitrogen atom alone. Under alkaline conditions APH is deprotonated in the presence of palladium(II) to form [Pd(AP)2] (10), AP being an anionic bidentate ligand and chelating through the pyridine-nitrogen and amide-oxygen atoms. The poly-chelates are of 1:1 and 1:3 (metal:homopolymer) stoichiometry and exhibit six-coordination. The polymer complexes of stoichiometric [(APH)2CuX2] contain square planar (APH)2 Cu2+ units and the anions X, are in the axial positions, giving distorted octahedral configurations. From the electron paramagnetic resonance and spectral data, the orbital reduction factors were calculated. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||