Synthesis of Novel Tetracarboxylato Dirhenium(III) Compounds and Crystal Structure of [Re2(1-Adamantylcarboxylate)4Cl2] · 4 CHCl3

2001 ◽  
Vol 56 (4-5) ◽  
pp. 381-385 ◽  
Author(s):  
Alexander V. Shtemenko ◽  
Alexander A. Golichenko ◽  
Konstantin V. Domasevitch

Abstract The coordination compounds o f the general formula Re2 (L)4X2 (X = Cl, Br; L = 1 -adamantyl-carboxylate and 1 -adamantylacetate) have been prepared and characterized by means of UV-VIS spectroscopy (20000 cm-1 , δ → δ*). The crystal and molecular structure of Re2(AdCOO)4Cl2 · 4 CHCl3 solvate was determined by X-ray diffraction. The units Re2(AdCOO)4Cl2 adopt a centrosymmetric dinuclear array with each metal atom coordinated in a distorted octahedron comprising one rhenium and one chlorine atoms (Re-Cl 2.505(2) Å) and four carboxylate oxygen atoms in the equatorial plane. The rhenium-rhenium separation of 2.2300(5) Å corresponds to quadruple bond between the metal atoms. All R e-0 bonds have an almost uniform length (2.017(4) -2.032(4) Å) and do not differ essentially from the parameters reported for related compounds. The closest environment of the Re2(AdCOO)4Cl2 molecules in the crystal comprises weak Cl---HC hydrogen bonds with the chloroform molecules and significantly shortened van der Waals contacts Cl---Cl, 3.46 Å.

1999 ◽  
Vol 54 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Miguel Monge Oroz ◽  
Annette Schier ◽  
Hubert Schmidbaur

Mononuclear coordination compounds of the type (R3P)AuSiR′3 with R = R’ = Ph and R = Me, R′ = Ph have been obtained from reactions of the corresponding halide complexes (R3P)AuCl with the silyllithium reagent LiSiPh3. The fully phenylated species undergoes ligand redistribution in solution to give homoleptic ionic species. (Me3P)AuSiPh3 is less susceptible to this process and crystallizes from solutions as the heteroleptic complex. The crystal structure of this compound has been determined by X-ray diffraction. In the crystal lattice the molecules are not associated.


1981 ◽  
Vol 34 (1) ◽  
pp. 65 ◽  
Author(s):  
GA Williams ◽  
R Robson

The crystal and molecular structure of LCO2 [S2P(OEt)2]2 (where L is a binucleating ligand derived from the macrocycle LH2 formed by condensation of two molecules each of propane-1,3-diamine and 2-hydroxy-5-methylisophthalaldehyde) has been determined by single-crystal X-ray diffraction techniques at 295 K. The compound crystallizes in the triclinic space group Pī with two molecules in a cell of dimensions a 18.644(6), b 11.694(4), c 9.487(4) �, α 84.99(3), β 82.61(3), γ 73.48(2)�. Automatic diffractometry has provided significant Bragg intensities for 2799 independent reflections and the structure has been refined by least-squares methods to R 0.054. The structure is molecular, consisting of discrete binuclear units LCo2[S2P(OEt)2]2. The two centrosymmetric molecules in the unit cell are crystallographically unique but essentially chemically similar. The two cobalt(11) atoms in each molecule are separated by 3.075(2) and 3.072(2) �. Each cobalt atom is in an octahedral environment, with an N2O2 equatorial plane and two sulfur atoms of bridging dithiophosphate ligands in the axial positions. The Co-S bonds are the longest yet observed [2,680(3), 2.652(3), 2.642(3), 2.623(3) �]. The cobalt(11) centres are high spin, with �eff 4.53 BM per cobalt atom. The macrocyclic ligand deviates slightly from planarity. The forces exerted both by the ligand L on associated metal atoms, and by axial ligands on the macrocycle, are discussed.


1975 ◽  
Vol 28 (6) ◽  
pp. 1201 ◽  
Author(s):  
CJ Commons ◽  
BF Hoskins

The crystal and molecular structure of the n-hexane solvate of μ- bis(diphenylarsino)methane-hexacarbonyldi-μ-chloro-dirhenium(I), Re2(CO)6(Ph2AsCH2AsPh2)Cl2, has been determined by three-dimensional X-ray diffraction methods. The complex crystallizes in the space group Pī with a 15.763(1), b 19.077(1), c 12.233(1) Ǻ and α 88.745(10), β 110.506(5), γ 92.900(6)�. The structure was solved by conventional Patterson and Fourier methods and refined by a block-diagonal least- squares method to R and Rw of 0.045 and 0.054, respectively, for 7061 independent statistically significant reflections collected by counter methods. The crystal consists of discrete molecules of the complex and n-hexane held together by van der Waals forces. There are two molecules of the dirhenium complex in the crystallographic asymmetric unit with the n-hexane molecule situated about a site of symmetry ī. The binuclear rhenium complex contains bridging halogen atoms and a bridging diarsine ligand. Three carbonyl ligands are also bonded to each rhenium atom, giving the metal atoms approximately octahedral environments. The average Re-As, Re-Cl, and Re-C bond lengths are 2.58, 2.52, and 1.89 Ǻ respectively.


1997 ◽  
Vol 75 (5) ◽  
pp. 475-482 ◽  
Author(s):  
Wei Xu ◽  
Alan J. Lough ◽  
Robert H. Morris

New amineruthenium and amineiridium hydride derivatives have been synthesized and characterized with the objective of observing intramolecular [Formula: see text] or [Formula: see text] interactions. These include RuHCl(CO)(L)(PPri3)2 (1a, L = NH2NH2; 1b, L = NH3) and IrCl2(L)(H)(PCy3)2 (2a, L = SC(NH2)2; 2b, L = NH3; 2c, L = NH2NH2; 2d, L = NH2(CH2)3NH2; 2e, L = NH2OH). Instead, weak [Formula: see text] van der Waals contacts have been detected in the solid state by X-ray analysis and in solution by NMR T1 measurements and nOe techniques. Both X-ray crystal structure analysis and minimum T1 measurements indicate that the [Formula: see text] distances in the [Formula: see text] interactions are ca•2.0–2.2 Å. The weak interactions might influence the course of deuteration of these complexes under D2 gas. The crystal and molecular structure of IrCl2(NH3)(H)(PCy3)22a has been determined by X-ray diffraction at 173 K: monoclinic, space group P21/n, a = 14.859(2) Å, b = 18.579(3) Å, c = 18.548(3) Å, β = 97.29(1)°, V = 5079.1(13) Å3, Z = 4, full-matrix least-squares refinement on F2 for 10 953 independent reflections; R[F2 > 4σ(F2)] = 0.0283, wR(F2) = 0.0704. Keywords: ruthenium, iridium, hydride, dihydrogen, complexes, hydrogen bond, NMR, X-ray.


2007 ◽  
Vol 1007 ◽  
Author(s):  
Fabien Choffat ◽  
Sara Fornera ◽  
Paul Smith ◽  
Walter Caseri

ABSTRACTPolystannanes, i.e. organometallic polymers of the chemical formula (SnR2)n, are relatively little explored, although they belong to the rare examples of polymers which are characterized by a backbone of metal atoms which are linked by covalent bonds. We developed a new synthetic route which yields pure linear poly(dibutylstannane) [Sn(Bu)2]n by polymerization of dibutylstannane (dibutyltin dihydride) with the catalyst [RhCl(PPh3)3]. Here, we report that the conversion and the reaction rate of dibutylstannane depends crucially on the temperature and [RhCl(PPh3)3] is also suited for the polymerization of dioctylstannane and didodecylstannane. The polymers thus obtained were characterized by 1H, 13C and 119Sn NMR spectroscopy: Orientation of all polystannanes was achieved by tensile drawing. The orientation was examined by UV-vis spectroscopy with polarized light and X-ray diffraction. Remarkably, the orientation of the backbone depended on the length of the alkyl groups.


2020 ◽  
Vol 67 (4) ◽  
pp. 1155-1162
Author(s):  
Fu-Ming Wang ◽  
Li-Jie Li ◽  
Guo-Wei Zang ◽  
Tong-Tong Deng ◽  
Zhong-Lu You

A new copper(II) complex [Cu(L1)(NCS)(CH3OH)] (1) and a new zinc(II) complex [ZnCl2(HL2)] · CH3OH (2), derived from 4-bromo-N’-(pyridin-2-ylmethylene)benzohydrazide (HL1) and 4-methoxy-N’-(pyridin-2-ylmethylene)benzohydrazide (HL2), were prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy and single crystal X-ray diffraction. The hydrazone HL1 coordinates to the Cu atom in enolate form, while the hydrazone HL2 coordinates to the Zn atom in carbonyl form. Single crystal structural analyses indicate that the hydrazones coordinate to the metal atoms through the pyridine N, imino N, and enolate/carbonyl O atoms. The Cu atom in complex 1 is in square pyramidal coordination, and the Zn atom in complex 2 is in trigonal-bipyramidal coordination. The inhibitory effects of the complexes on Jack bean urease were studied, which show that the copper complex has strong activity on urease.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1257-C1257
Author(s):  
Marcos Ribeiro ◽  
Humberto Stumpf ◽  
Carlos Pinheiro

The search for new functional materials involves the development of bistable molecules exhibiting different electronic states with distinct properties at the ambient condition (temperature, pressure, illumination) of application. Coordination compounds, which present electron transfer between metal ion and an organic ligand associated with a change in electron multiplicity of the metal ion, are named valence tautomers(VT)[1]. The chemical equilibrium between two distinct electronic states in VT can be induced by temperature and pressure change as well as by soft X-ray and light irradiation. Thermodynamic and structural data highlighting the mechanisms of the valence tautomerism interconversion can be found in the literature for materials build up with cobalt and benzoquinones such as the 3,5-di-t-butyl-semiquinonate. However, to the best of our knowledge, there is no example of compounds showing VT build up with cobalt and naphthoquinones. In the present work 2-hydroxy-1,4-naphthoquinone (law) has been used as redox active ligands in the search for new VT compounds with cobalt. Three new coordination compounds of cobalt and 2-hydroxy-1,4-naphthoquinone (law), [Co(law)2(im)2], [Co(law)2(phen)] e [Co(law)2(bpy)] were synthesized and characterized by infrared (IR), UV-vis spectroscopy, electron paramagnetic resonance (EPR) and cyclic voltammetry. The three dimensional structures were determined using single crystal X-ray diffraction techniques. However, within the investigated temperature range neither X-ray diffraction nor EPR data showed the presence of VT in the materials, mainly due to the electrochemical properties of the 2-hydroxy-1,4-naphthoquinone. Nevertheless the structural features of the compounds as well as their supramolecular packing motifs suggest that naphthoquinones can be an alternative for the synthesis of compounds showing valence tautomerism[3].


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.


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