Search results for " Geometry"
showing 10 items of 2294 documents
Cooperative H-bonds, π⋯π and anion⋯π interactions as driving forces in the construction of novel Cu(II) bis(imidazol-2-yl) supramolecular 3D framewor…
2019
Abstract Two new Cu(II) complexes with bis(2-imidazolyl) based ligands, with the formula [Cu(BIM)2(SCN)2]·2H2O (BIM = bis(2-imidazol-2-yl)methane) and [Cu(HBIMAM)2(OH2)2](BF4)4·2H2O (BIMAM = bis(2-imidazol-2-yl)methylaminomethane) have been synthesized and characterized. Both compounds contain mononuclear entities as molecular building blocks (MBBs); neutral [Cu(BIM)2(SCN)2] in compound 1 and cationic [Cu(HBIMAM)2(OH2)2]4+ in compound 2. The coordination around the metal atoms shows a tetragonally-elongated octahedral geometry (CuN4S2 and CuN4O2 chromophores). The Q-band EPR spectra of both compounds are indicative of an essentially d x 2 - y 2 ground state for copper(II) ions. The analysis…
The separation of cis- and trans-1,3-cyclohexanediol isomers by copper complexation. Crystal structures of cis-1,3-cyclohexanediol and copper(II) chl…
2002
Abstract A 1:1 complex between copper(II) chloride and cis-1,3-cyclohexanediol has been synthesized and its crystal structure determined. The structure is composed of two different dinuclear [CuCl2(c-13chd)]2 units in which the copper(II) ions are surrounded by the two oxygen atoms of the diol and the two halide ions in a distorted cis-square planar arrangement in both cases. A fifth coordination site is occupied by a halide ion in one dinuclear unit for both copper ions and an O atom belonging to the adjacent CuCl2(c-13chd) moiety in the other dinuclear unit for both copper ions, thus forming a distorted square pyramidal geometry for the metals in all cases. The ability of CuCl2 to prefere…
Enhancement of the Intermolecular Magnetic Exchange through Halogen···Halogen interactions in Bisadeninium Rhenium(IV) Salts
2017
Two novel ReIV salts of general formula [H2ade]2[ReIVX6]X2·4H2O [H2ade2+ = 9H-adenine-1,7-diium; X = Cl(1) and Br(2)] have been synthesized and magneto-structurally characterized. 1 and 2 are isostructural salts that crystallize in the orthorhombic system with space group Fdd2. Both compounds are made up of discrete mononuclear [ReIVX6]2- and X- anions and doubly protonated adenine cations. The six-coordinate rhenium(IV) ion is bonded to six halide ligands [X = Cl (1) and Br (2)] in an octahedral geometry. Short intermolecular ReIV−X···X−ReIV interactions, as well as ReIV−X···H−N(H2ade) and ReIV−X···H−Ow hydrogen bonds, are present in the crystal lattice of 1 and 2. Magnetic suscep-tibility…
Linking PO43− and HAsO42− anions with a dinuclear [ZnII2] complex: Formation and stabilization of novel decanuclear metallomacrocyclic [ZnII10] and t…
2017
The linkage of PO43- and HAsO42--anions with a newly synthesized five-coordinate dinuclear zinc complex, Zn-2(cpdp)(H2O)(2)]Cl (1) H(3)cpdp =N,N'-bis2-carboxybenzomethyl]-N,N'-bis2-pyridylmethyl]-1,3diamino propan-2-ol], has been explored. In methanol-water, the reaction of 1 with Na2HPO4 center dot 2H(2)O and Na2HAsO4 center dot 7H(2)O/NaBr separately, at ambient temperature, yielded the novel phosphate-bridged decanuclear zinc cluster, (H3O)(4)Zn-10(cPdP)(4)(mu(5)-PO4)(2)(H2O)(6)](6 center dot Cl)center dot 53H(2)O (2) and hydrogen arsenate bridged tetranuclear zinc cluster, Na-2Zn-4(cpdp)(2)(mu(4)-HAsO4)]ClBr center dot 13H(2)O (3), respectively. Analysis of the single crystal X-ray stru…
Zinc(ii), cobalt(ii) and manganese(ii) networks with phosphoserine ligand: synthesis, crystal structures and magnetic and proton conductivity propert…
2017
A series of zinc(II), cobalt(II) and manganese(II) coordination networks with phosphoserine ligand (H3PSer) are synthesized and characterized. Whereas in compounds 1 and 2 with the general formula [M(HPser)]n [M = Zn (1) and Co (2)], the metal(II) ion presents a tetrahedral geometry, in [Co(HPSer)(H2O)2]n (3) and [Mn(HPSer)(H2O)]n (4), the metal(II) ions are in a distorted octahedral geometry. The 3D frameworks are formed by inorganic layers built up from MO4 or MO6 polyhedra and phosphate groups. These layers are linked by the carboxylate groups of the phosphoserine ligand. The presence of extended hydrogen bonding stabilizes the 3D network and favours the proton transfer leading to modera…
Oxygen Transfer from Trimethylamine N ‐Oxide to Cu I Complexes Supported by Pentanitrogen Ligands
2020
[N,N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L1) and [N,N-bis(2-quinolylmethyl)-N-bis(2-pyridyl)methylamine] (L2) were employed to prepare CuII and CuI complexes for spectroscopic and structural characterization. [L1CuII(H2O)](NO3)2 and [L2CuII(NO3)]NO3 have Jahn–Teller distorted octahedral geometries and give rise to isotropic EPR spectra in frozen solution. [L1CuI(CH3CN)]OTf and [L2CuI(CH3CN)]OTf have distorted trigonal bipyramidal and tetrahedral solid-state structures, respectively. The N-donors display labile behavior in solution, based on variable-temperature 1H NMR studies. Addition of trimethylamine N-oxide (Me3NO) to solutions of [L1CuI(CH3CN)]OTf and [L…
Influence of the solvent and R groups on the structure of (carboranyl)R2PI2 compounds in solution. Crystal structure of the first iodophosphonium sal…
2008
The influence of the electron-donor or electron-acceptor capacity of the R groups (R = (i)Pr, Ph, Et) and the solvent on the molecular geometry in solution of adducts of carboranylphosphanes [(carboranyl)(i)Pr2P, (carboranyl)Ph2P and (carboranyl)Et2P] with I2 in 1 : 1 ratios, has been studied in detail by 31P{1H} and 11B{1H} NMR spectroscopies. The more electron-accepting Ph groups make the (carboranyl)Ph2P less nucleophilic, thus stabilizing the I2 encapsulated neutral biscarboranylphosphane-diiodine adducts in solution, such as (carboranyl)Ph2PI-IPPh2(carboranyl), generating P---I-I---P motifs. Even in a polar solvent, such as EtOH, the arrangement is preserved. The expected basicity of t…
Cytosine Nucleobase Ligand: A Suitable Choice for Modulating Magnetic Anisotropy in Tetrahedrally Coordinated Mononuclear CoII Compounds
2017
A family of tetrahedral mononuclear CoII complexes with the cytosine nucleobase ligand is used as the playground for an in-depth study of the effects that the nature of the ligand, as well as their noninnocent distortions on the Co(II) environment, may have on the slow magnetic relaxation effects. Hence, those compounds with greater distortion from the ideal tetrahedral geometry showed a larger-magnitude axial magnetic anisotropy (D) together with a high rhombicity factor (E/D), and thus, slow magnetic relaxation effects also appear. In turn, the more symmetric compound possesses a much smaller value of the D parameter and, consequently, lacks single-ion magnet behavior.
Cadmium(ii) coordination polymers based on substituted malonic acid: synthesis, characterization and photoluminescence properties
2017
Four novel complexes of cadmium(II) with alkyl/aryl-substituted malonate ligands of formulae {[Cd(Memal)(H2O)]6·0.5H2O}n (1), [Cd(Etmal)(H2O)]n (2), [Cd(Butmal)(H2O)]n (3) and [Cd(Bzmal)(H2O)]n (4), (Memal = methylmalonate, Etmal = ethylmalonate, Butmal = butylmalonate and Bzmal = benzylmalonate) have been prepared and characterized by single crystal X-ray analysis. Their luminescence, UV-Vis absorption properties and thermal behaviour were also investigated. Complex 1 is a three-dimensional compound where each metal centre is connected to four other ones leading to a sodalite network with the point symbol {42·64}. Each cadmium(II) ion in 1 is seven-coordinate with a water molecule and six …
Modulating the DNA cleavage ability of copper(II) Schiff bases through ternary complex formation
2018
Copper(II) complexes with the potentially tridentate Schiff bases N-[(3-ethoxy-2-hydroxyphenyl)methylidene]-N′-tosylbenzene-1,2-diamine (H2L1) and N-[(2-hydroxynaphthanyl)methylidene]-N′-tosylbenzene-1,2-diamine (H2L2) have been synthesized by electrochemical oxidation of the metal in an electrochemical cell containing a solution of the corresponding ligand in acetonitrile. Adducts of these compounds with 2,2′-bipyridine (2,2′-bpy), 4,4′-bipyridine (4,4′-bpy) or 1,10-phenanthroline (phen) were also obtained. The complexes have been characterized by microanalysis, mass spectrometry, EPR, IR and UV-Vis spectroscopies, as well as DFT calculations. The ligand H2L1 and the compounds [CuL1(H2O)]·…