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Terminal Ligands (terminal + ligand)

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Chemistry100%

Selected Abstracts

Cyanometalate Cages with Exchangeable Terminal Ligands

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2007
Julie L. Boyer
Abstract The coordination chemistry of the unusual metallo-ligand Cs,[CpCo(CN)3]4[Cp*Ru]3 (Cs,Co4Ru3) is described with attention to the behavior of the ligand itself, its binding to Lewis-acidic metal cations, and its ability to stabilize catalytically relevant Ru,PPh3 fragments. A series of tests demonstrate that the "rim" [CpCo(CN)3], groups in Cs,Co4Ru3 are exchangeable. Upon treatment with [(MeC5H4)Co(CN)3], (Co,) Cs,Co4Ru3 undergoes vertex exchange to give Cs,Co4,xCo,xRu3. Similarly the cage is degraded by CO. Most convincing, Cs,Co4Ru3 reacts with PhNH3OTf to precipitate the polymer PhNH3CpCo(CN)3 and form the molecular box [Cs,Co4Ru4]+. Treatment of Cs,Co4Ru3 with [M(NCMe)x]PF6 (M = Cu, Ag) gave the Lewis acidic cages {Cs,[CpCo(CN)3]4[Cp*Ru]3M(NCMe)}PF6, which reacted with tertiary phosphane ligands to give adducts [Cs,Co4Ru3M(PPh3)]PF6. Lewis acidic octahedral vertices were installed using Fe, Ni, and Ru reagents. The boxes [Cs,Co4Ru3M(NCMe)3]2+ (M = Ni, Fe) formed readily from the reaction Cs,Co4Ru3 with [Ni(NCMe)6](BF4)2 and [Fe(NCMe)6](PF6)2. Displacement of the MeCN ligands gives [Cs,Co4Ru3Ni(9-ane-S3)](BF4)2. A series of boxes were prepared by the reaction of Cs,Co4Ru3 and RuCl2(PPh3)3, RuHCl(PPh3)3, and [(C6H6)Ru(NCMe)3](PF6)2. The derivative of the hydride, [Cs,Co4Ru3Ru(NCMe)(PPh3)2](PF6)2, was characterized crystallographically.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Experimental and Theoretical Evidence of ,-d Interactions in Supramolecular Assemblies Based on TTF-CH=CH-Py Ligands Tethered to Mo6Xi8 Octahedral Molybdenum Halide Cluster Cores

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009
Ganesan Prabusankar
Abstract Synthesis, characterization, and physical properties of [Mo6Xi8(TTF-CH=CH-Py)a6]4+ supramolecular assemblies [TTF = tetrathiafulvalene; Py = pyridine; X = Cl (1), Br (2),I (3)] resulting from the reaction between [Mo6Xi8(OSO2CF3)6]2, cluster precursor and TTF-CH=CH-Py ligands were investigated. They are based on the association of the strongly delocalized metallic electron [Mo6Xi8]4+ cluster cores with six redox-active ,-conjugated TTF-CH=CH-Py terminal ligands attached to the Mo clusters through the pyridinyl group. Synergetic ,-d interactions between the organic ligands and the cluster core were experimentally evidenced by electrochemistry and absorption measurements, and corroborated by DFT calculations.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

Solid-State Anion,Guest Encapsulation by Metallosupramolecular Capsules Made from Two Tetranuclear Copper(II) Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 29 2007
Emilio Pardo
Abstract A new cationic tetranuclear copper(II) complex self-assembles from one 1,3-phenylenebis(oxamato) (mpba) bridging ligand and four CuII ions partially blocked with N,N,N,,N, -tetramethylethylenediamine (tmen) terminal ligands. In the solid state, two of these tetracopper(II) oxamato complexes of bowl-like shape and helical conformation then serve as a building block for the generation of either hetero- (MP) or homochiral (MM/PP) dimeric capsules depending on the nature of the encapsulated anion guest, perchlorate or hexafluorophosphate. The overall magnetic behaviour of these metallosupramolecular capsules does not depend on the nature of the encapsulated anion guest, but it is consistent with the dimer-of-dimer structure of the tetracopper(II) cation host, where the interdimer magnetic coupling through the meta -phenylenediamidate bridge is negligibly smallrelative to the reasonably strong intradimer one across the oxamato bridge.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Rarely Decorated Rutile Frameworks Built from Triangular Organic Spacers and Distorted Octahedral Co3 Building Blocks

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 24 2007
Feng Luo
Abstract Under mild temperatures, the self-assembly of CoCl2 and H3BTC in a solution of dmso generates a guest-free metal,organic polymer, namely Co3(BTC)2(,1 -dmso)2(,2 -dmso)2(1: dmso = dimethylsulfoxide, H3BTC = 1,3,5-benzenetricarboxylic acid). In 1, the CoII ions show the six-coordinate octahedral geometry completed by the BTC3, ions and the dmso oxygen atoms; remarkably, the coordinated dmso ligands not only act as terminal ligands to complete the octahedral geometry of the CoII ions, but also play an important role in bridging CoII ions together to give the Co3 secondary building units (SBUs). From a topological viewpoint, this novel polymer is classified to be the decorated (3,6)-connected rutile net with the (4.62)2(42.610.83) topology, where BTC3, ligands and Co3 SBUs are viewed to be the 3- and 6-connected nodes, respectively. In addition, the magnetic properties of 1 are explored by using a linear trinuclear cobalt mode, thusleading to g = 2.41, J = ,34.92 cm,1, TIP = 340,×,10,6 cm3,mol,1,, = ,6 K (a , parameter was included to take into account intertrinuclear interactions).(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

A Theoretical Study of the Exchange Coupling in Hydroxo- and Alkoxo-Bridged Dinuclear Oxovanadium(IV) Compounds

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2004
Antonio Rodríguez-Fortea
Abstract A density functional study of exchange coupling in hydroxo- and alkoxo-bridged dinuclear oxovanadium(IV) compounds is presented. Coupling constants calculated for full unmodeled structures are in good agreement with experimentally reported values, confirming the ability of the computational strategy used in this work to predict the exchange coupling in dinuclear VIV compounds. The influence of the configuration of the [VO(,-OR)2VO]2+ core in compounds with two edge-sharing octahedrally coordinated oxovanadium(IV) centers, of the nature of the terminal ligands and of structural distortions on the coupling constant have been analyzed through model calculations. The results indicate that the coupling constant is less affected by these factors than for hydroxo- and alkoxo-bridged CuII compounds. The calculations support the orbital models usually employed in qualitative interpretations of magneto-structural correlations, showing good correlations between the calculated coupling constants and the overlap between the two magnetic orbitals or the square of the orbital gap. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

An unusual chain cadmium(II) coordination polymer: catena -poly[[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-chlorido-[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-thiocyanato-,2N:S;,2S:N]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007
Min Chen
The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual CdII coordination polymer constructed by two types of anionic bridges and 2,2,-bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the CdII center is provided by two chloride ions, one N- and one S-donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent CdII ions are interconnected alternately by paired chloride [Cd...Cd = 3.916,(1),Å] and thiocyanate bridges [Cd...Cd = 5.936,(1),Å] to generate an infinite one-dimensional coordination chain. Furthermore, weak interchain C,H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure. [source]

A novel thio­cyanate-bridged one-dimensional chain complex: [Cu(NCS)2(Hambi)] (Hambi is 2-amino­methyl-1H -benz­imidazole)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2004
Yun-Bo Jiang
Using 2-amino­methyl-1H -benz­imidazole as the ligand, a new thio­cyanate-bridged copper(II) complex, namely bis(2-aminomethyl-1H -benz­imidazole-,2N2,N3)­di­thio­cyanato­copper(II),[Cu(NCS)2(C8H9N3)], has been synthesized and structurally characterized. The Cu atom is five-coordinated and exhibits a distorted square-pyramidal geometry. The thio­cyanate ions (NCS,) act as either bridging or terminal ligands. The bridging NCS, ligands connect neighboring Cu atoms, constructing chains, while the terminal NCS, ligands form hydrogen bonds with amine H atoms, leading to a complicated network. [source]

New Metal-Organic Frameworks with Large Cavities: Selective Sorption and Desorption of Solvent Molecules

CHEMISTRY - A EUROPEAN JOURNAL, Issue 26 2007
Yan Wang
Abstract Five novel transition metal complexes [CdII3(tpba-2)2(SCN)6],6,THF,3,H2O (1), [CuII3(tpba-2)2(SCN)6],6,THF,3,H2O (2), [NiII3(tpba-2)2(SCN)6],6,THF,3,H2O (3), [CdII2(tpba-2)(SCN)3]ClO4 (4), [CuI3(SCN)6(H3tpba-2)] (5) [TPBA-2 = N,,N,,,N,,, -tris(pyrid-2-ylmethyl)-1,3,5-benzenetricarboxamide, THF=tetrahydrofuran] were obtained by reactions of the corresponding transition metal salts with TPBA-2 ligand in the presence of NH4SCN using layering or solvothermal method, respectively. The results of X-ray crystallographic analysis showed that complexes 1, 2 and 3 are isostructural and have the same 2D honeycomb network structure with Kagomé lattice, in which all the MII (M = Cd, Cu, Ni) atoms are six-coordinated, and the TPBA-2 ligands adopt cis,cis,cis conformation while the thiocyanate anions act as terminal ligands. Capsule-like motifs are found in 1, 2 and 3, in which six THF molecules are hosted, and the results of XPRD and solid-state 13C,NMR spectral measurements showed that the compound 1 can selectively desorb and adsorb THF molecules occurring along with the re-establishment of its crystallinity. In contrast to 1, 2 and 3, complex 4 has different 2D network structure, resulting from TPBA-2 ligands with cis,trans,trans conformation, thiocyanate anions serving as end-to-end bridging ligands, and the incomplete replacement of perchlorate anions, which further link the 2D layers into 3D framework by the hydrogen bonds. In complex 5, the CuII atoms are reduced to CuI during the process of solvothermal reaction, and the CuI atoms are connected by thiocyanate anions to form a 3D porous framework, in which the protonated TPBA-2 ligands are hosted in the cavities as templates. [source]