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Octahedral Coordination Environment (octahedral + coordination_environment)
Selected AbstractsRuthenium ONO-Type Pincer Complex: Synthesis, Structural Characterization, and CatalysisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Yao Zhang Abstract A novel nitrone-based pincer ligand was developed by a single-step synthesis from N -(tert -butyl)hydroxylamine acetate and 2,6-pyridinedicarboxaldehyde. The developed ligand allowed us to synthesize a cationic ruthenium pincer complex. A distorted octahedral coordination environment around the ruthenium center was observed. The complex showed excellent catalytic activity in transfer hydrogenation reactions with turnover numbers up to 590,000. [source] trans -Diaquabis(nicotinamide-,N)bis(salicylato-,O)cobalt(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2008The title compound, [Co(C7H5O3)2(C6H6N2O)2(H2O)2], forms a three-dimensional hydrogen-bonded supramolecular structure. The CoII ion is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N,H...O and O,H...O hydrogen bonds produce R22(8), R22(12) and R22(14) rings, which lead to two-dimensional chains. An extensive three-dimensional supramolecular network of C,H...O, N,H...O and O,H...O hydrogen bonds and C,H..., interactions is responsible for crystal structure stabilization. This study is an example of the construction of a supramolecular assembly based on hydrogen bonds in mixed-ligand metal complexes. [source] (N -{[4-(1,3-Benzothiazol-2-yl)anilino]carbonylmethyl-,O}iminodiacetato-,3O,N,O,)(1,10-phenanthroline-,2N,N,)cobalt(II) pentahydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2008Guo-Wu Lin The title compound, [Co(C19H15N3O5S)(C12H8N2)]·5H2O, has a moderately distorted octahedral coordination environment composed of two N atoms of a 1,10-phenanthroline ligand and one N and three O atoms of an N -{[4-(1,3-benzothiazol-2-yl)anilino]carbonylmethyl}iminodiacetate (ZL-52,) ligand. The ring systems of the phenanthroline and ZL-52, ligands are coplanar and the complexes pack in layers parallel to the ab plane with the rings of adjacent complexes facing one another. The layers stack along the c axis and are linked by hydrogen bonds involving the five water solvent molecules in the asymmetric unit and O atoms of the acetate groups of the ZL-52, ligand. This is believed to be the first crystal structure of a complex of a 2-(4-aminophenyl)benzothiazole ligand. [source] Bis(5-aminotetrazole-1-acetato-,O)tetraaquacobalt(II) and catena -poly[[cadmium(II)]-bis(,-5-aminotetrazole-1-acetato-,3N4:O,O,)]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2008Qiao-Yun Li The CoII atom in bis(5-aminotetrazole-1-acetato)tetraaquacobalt(II), [Co(C3H4N5O2)2(H2O)4], (I), is octahedrally coordinated by six O atoms from two 5-aminotetrazole-1-acetate (atza) ligands and four water molecules. The molecule has a crystallographic centre of symmetry located at the CoII atom. The molecules of (I) are interlinked by hydrogen-bond interactions, forming a two-dimensional supramolecular network structure in the ac plane. The CdII atom in catena -poly[[cadmium(II)]-bis(,-5-aminotetrazole-1-acetato], [Cd(C3H4N5O2)2]n, (II), lies on a twofold axis and is coordinated by two N atoms and four O atoms from four atza ligands to form a distorted octahedral coordination environment. The CdII centres are connected through tridentate atza bridging ligands to form a two-dimensional layered structure extending along the ab plane, which is further linked into a three-dimensional structure through hydrogen-bond interactions. [source] Synthesis, Structure, and Physico-optical Properties of Manganate(II)-Based Ionic LiquidsCHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2010Slawomir Pitula Dr. Abstract Several ionic liquids (ILs) based on complex manganate(II) anions with chloro, bromo, and bis(trifluoromethanesulfonyl)amido (Tf2N) ligands have been synthesized. As counterions, n- alkyl-methylimidazolium (Cnmim) cations of different chain length (alkyl=ethyl (C2), propyl (C3), butyl (C4), hexyl (C6)) were chosen. Except for the 1-hexyl-3-methylimidazolium ILs, all of the prepared compounds could be obtained in a crystalline state at room temperature. However, each of the compounds displayed a strong tendency to form a supercooled liquid. Generally, solidification via a glass transition took place below ,40,°C. Consequently, all of these compounds can be regarded as ionic liquids. Depending on the local coordination environment of Mn2+, green (tetrahedrally coordinated Mn2+) or red (octahedrally coordinated Mn2+) luminescence emission from the 4T(G) level is observed.1 The local coordination of the luminescent Mn2+ centre has been unequivocally established by UV/Vis as well as Raman and IR vibrational spectroscopies. Emission decay times measured at room temperature in the solid state (crystalline or powder) were generally a few ms, although, depending on the ligand, values of up to 25,ms were obtained. For the bromo compounds, the luminescence decay times proved to be almost independent of the physical state and the temperature. However, for the chloro- and bis(trifluoromethanesulfonyl)amido ILs, the emission decay times were found to be dependent on the temperature even in the solid state, indicating that the measured values are strongly influenced by nuclear motion and the vibration of the atoms. In the liquid state, the luminescence of tetrahedrally coordinated Mn2+ could only be observed when the tetrachloromanganate ILs were diluted with the respective halide ILs. However, for [C3mim][Mn(Tf2N)3], in which Mn2+ is in an octahedral coordination environment, a weak red emission from the pure compound was found even in the liquid state at elevated temperatures. [source] A mixed-valence chair-like tetranuclear copper(I,II) cluster with three linking modes of the 3,5-bis(2-pyridyl)-1,2,4-triazole ligandACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010Quan-Guo Zhai In the tetranuclear copper complex tetrakis[,-3,5-bis(2-pyridyl)-1,2,4-triazolido]bis[3,5-bis(2-pyridyl)-1,2,4-triazolido]dicopper(I)dicopper(II) dihydrate, [CuI2CuII2(C12H8N5)6]·2H2O, the asymmetric unit is composed of one CuI center, one CuII center, three anionic 3,5-bis(2-pyridyl)-1,2,4-triazole (2-BPT) ligands and one solvent water molecule. The CuI and CuII centers exhibit [CuIN4] tetrahedral and [CuIIN6] octahedral coordination environments, respectively. The three independent 2-BPT ligands adopt different chelating modes, which link the copper centers to generate a chair-like tetranuclear metallomacrocycle with metal,metal distances of about 4.4 × 6.2,Å disposed about a crystallographic inversion center. Furthermore, strong ,,, stacking interactions and O,H...N hydrogen-bonding systems link the tetracopper clusters into a two-dimensional supramolecular network. [source] | ||||||||||