Search results for "Pyramid"
showing 10 items of 410 documents
Discrete trinuclear copper(II) compounds as building blocks: the influence of the peripheral substituents on the magnetic coupling in oxamato-bridged…
2014
Two new trinuclear copper(ii) complexes without end-capping ligands, (Bu4N)2[Cu(dmso)2{Cu(dnopba)(dmso)}2] () and (Bu4N)2[Cu(dmso)2{Cu(dcopba)(dmso)}2] () [dnopba = 4,5-dinitro-ortho-phenylenebis(oxamate), dcopba = 4,5-dichloro-ortho-phenylenebis(oxamate), Bu4N(+) = tetra-n-butylammonium and dmso = dimethylsulfoxide], were synthesized and their structures were determined by single crystal X-ray diffraction. The crystal structures of and consist of two outer bis(oxamato)(dmso)cuprate(ii) units which act as bidentate ligands toward a trans-bis(dmso)copper(ii) inner entity leading to centrosymmetric tricopper(ii) complexes with copper-copper separations across the oxamate bridges of 5.1916(3) …
Synthese und Strukturen neuer Eisen-Sauerstoff-Alkoxid-Cluster
2004
Der Eisen-Sauerstoff-Alkoxy-Cluster [Fe9O3(OC2H5)21]·C2H5OH kann unter unterschiedlichen Bedingungen zu Molekulen umgesetzt werden, denen alle die allgemeine Formel [Fe5O(OR)8(OR′)5] gemeinsam ist. Erwarmt man [Fe9O3(OC2H5)21]·C2H5OH in Toluol, so entsteht [Fe5O(OC2H5)13], das durch Kristallisation abgetrennt werden kann, wohingegen ein Auflosen von [Fe9O3(OC2H5)21]·C2H5OH in tert-Butylamin zum 1 : 2-Addukt [Fe5O(OC2H5)13]·2 t-Bu-NH2 fuhrt. Mit Triethyl- oder Triphenylsilanol entsteht aus [Fe9O3(OC2H5)21]·C2H5OH wieder ein Sauerstoff-Eisencluster des gleichen Motivs: [Fe5O(OC2H5)8{OSi(C2H5)3}5] bzw. [Fe5O(OC2H5)8{OSi(C6H5)3}5]. Die Molekulstruktur [Fe5O(OC2H5)8{OSi(C2H5)3}5], die uber Rontg…
Über Zinn‐haltige Heterocyclen, IV 1) 5,5‐Diphenyl‐1,4,6,5‐oxadithiastannocan, Fixierung eines konformativen Übergangszustandes in der Kristallstrukt…
1981
Die Titelverbindung 1f wurde durch Reaktion von Ph2SnCl2 mit dem Dinatriumsalz des Bis(2-mercaptoethyl)ethers gewonnen. Die Kristallstruktur wurde bestimmt und bis R = 0.054 verfeinert. Die Konformation des 8-gliedrigen Heterocyclus liegt im Bereich des Sattelpunktes fur den Ubergang Sessel-Sessel = Wanne-Sessel Konformation. Die Konfiguration um das Sn-Atom liegt zwischen tetraedrischer 4- und trigonal-bipyramidaler 5-Koordination (transannularer Sn···O-Abstand 266.0 (7) pm). On Heterocyclic Systems Containing Tin, IV1) 5,5-Diphenyl-1,4,6,5-oxadithiastannocane, a Conformational Transition State Stabilized in a Crystal Structure The title compound 1f has been synthesized from Ph2SnCl2 and t…
Synthesis and spectroscopic characterization of dicyclohexyltin derivatives of dipeptides, andin vitro effects against MDA-MB 231 breast cancer cells…
1992
Dicyclohexyltin derivatives Cy2SnL (Cy = cyclohexyl) of the dipeptides H2L, glycylglycine, glycylalanine, alanylglycine, glycylvaline, glycylmethionine, glycylphenylalanine and glycyltyrosine, have been obtained by neutralization of Cy2SnO and H2L. The crystal structures of Cy2SnL (L = glycylglycinate, glycylalaninate) have been determined by single X-ray diffraction. Tin in each case has a distorted trigonal bipyramidal environment with the dipeptide acting as a tridentate NNO-ligand. From IR-data, and in some cases from 119Sn Mossbauer and 119Sn NMR data, analogous molecular structures are inferred for the other compounds Cy2SnL. Spectroscopic data indicate that the solid-state structures…
Further synthetic investigation of the general lanthanoid(iii) [Ln(iii)]/copper(ii)/pyridine-2,6-dimethanol/carboxylate reaction system: {CuII5LnIII4…
2021
In addition to previously studied {CuII3Gd6}, {CuII8Gd4}, {CuII15Ln7} and {CuII4Ln8} coordination clusters (Ln = trivalent lanthanide) containing pdm2− or Hpdm− ligands (H2pdm = pyridine-2,6-dimethanol) and ancillary carboxylate groups (RCO2−), the present work reports the synthesis and study of three new members of a fifth family of such complexes. Compounds [Cu5Ln4O2(OMe)4(NO3)4(O2CCH2But)2(pdm)4(MeOH)2] (Ln = Dy, 1; Ln = Tb, 2; Ln = Ho, 3) were prepared from the reaction of Ln(NO3)3·xH2O (x = 5, 6), CuX2·yH2O (X = ClO4, Cl, NO3; y = 6, 2 and 3, respectively), H2pdm, ButCH2CO2H and Et3N (2 : 2.5 : 2 : 1 : 9) in MeCN/MeOH. Rather surprisingly, the copper(II)/yttrium(III) analogue has a sli…
Magnetic coupling and spin topology in linear oxalato-bridged tetranuclear chromium(III)–copper(II) complexes with aromatic diimine ligands
2013
Abstract A novel heterotetranuclear chromium(III)–copper(II) complex of formula {[CrIII(bpy)(ox)2]2CuII2(bpy)2(ox)}·6H2O (1) has been synthesized by the ligand exchange reaction between Ph4P[CrIII(bpy)(ox)2]·H2O and [CuII(bpy)2(NO3)]NO3·MeOH in methanol (bpy = 2,2′-bipyridine; ox2− = oxalate dianion). The X-ray crystal structure of 1 consists of neutral oxalato-bridged CrIII2Cu2II zigzag entities which are formed by the monodentate coordination of two [CrIII(bpy)(ox)2]− mononuclear anionic units through one of its two oxalato groups toward a [CuII2(bpy)2(ox)]2+ dinuclear cationic moiety featuring relatively long axial bonds at the square pyramidal CuII ions. Variable temperature (2.0–300 K)…
Structural diversity within analogous compounds: syntheses and studies of M(SCH2CH2NH2)Cl (M = Zn, Cd, Hg).
2006
The novel complexes [Zn(L)Cl] (1), [Cd(L)Cl] (2), [Hg(L)Cl] (3), {[Hg(L)Cl]·NaOH·2H 2 O} (3·NaOH·2H 2 O), and {[Hg 3 (HL) 2 Cl 6 ]·2H 2 O} (4) (L = -SCH 2 CH 2 NH 2 ) were prepared and investigated by means of IR spectroscopy and single-crystal X-ray diffraction. The crystal structures of 1, 2, and 3·NaOH·2H 2 O show chelating N,S-coordination of the cysteaminate ligand, bridging S, and terminally coordinating Cl. Apart from these common features, the coordination geometries and modes of intermolecular association are different. 1 forms a cyclic tetramer with a Zn 4 S 4 ring, and 3·NaOH·2H 2 O contains one-dimensional [Hg(L)Cl] n chains with S-bridged Hg atoms. Zn and Hg atoms in 1 and 3·Na…
Synthesis, crystal structures and magnetic properties of tricyanomethanide-containing copper(II) complexes
2008
The preparation, crystal structures and magnetic properties of the copper(II) complexes of formula [Cu(pyim)(tcm)(2)](n) (1), [Cu(bpy)(tcm)(2)](n) (2), [Cu(4)(bpz)(4)(tcm)(8)] (3), {[Cu(terpy)(tcm)].tcm}(n) (4) and {[Cu(2)(tppz)(tcm)(4)].3/2H(2)O}(n) (5) [pyim = 2-(2-pyridyl)imidazole, tcm = tricyanomethanide, bpy = 2,2'-bipyridine, bpz = 2,2'-bipyrazine, terpy = 2,2':6',2''-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine] are reported. Complexes, 1, 2 and 4 are uniform copper(II) chains with single- (1 and 4) and double-(2) micro-1,5-tcm bridges with values of the intrachain copper-copper separation of 7.489(1) (1), 7.520(1) and 7.758(1) (2) and 7.469(1) A (4). Each copper atom …
A unique single carboxylate-bridged spin-frustrated chiral Mn(II) metallatriangle.
2010
The reaction between Hmbpymca ligand (prepared in situ from the hydrolysis of 5-methyl-4-cyano-bispyrimidine with NaOH and further neutralization with 2 M HCl) and Mn(ClO(4))(2)·4H(2)O in 1:1 molar ratio afforded the triangulo-trimanganese(II) complex [Mn(3)(bpymca)(3)(H(2)O)(6)]Cl(3)·6H(2)O 1. The chloride anions in this complex come from the HCl used in the neutralization process. The molecular structure of 1 consists of cationic molecular triangles [Mn(3)(μ-mbpymca)(3)(H(2)O)(6)](3+) with C(3) symmetry, chloride anions and crystallization water molecules, all of them involved in an extensive network of hydrogen bonds, leading to a chiral network. Within the [Mn(3)(μ-mbpymca)(3)(H(2)O)(6)…
The structure of trinuclear Cu(II) complex with isonicotinic acid N-oxide, pentaaquadi-μ-hydroxobis-μ-(ionicotinato N-oxide)bis(isonicotinato N-oxide…
1983
Abstract A new trinuclear Cu(II) complex with isonicotinic acid N-oxide, [Cu3(N-inicO)4(OH)2(H2O)5·2H2O, has been prepared and its crystal structure determined by X-ray analysis. The complex crystallizes in the monoclinic space group P2/c with a = 12.051(4), b = 7.043(2), c = 19.825(6) A, β = 98.51(2)° and Z = 2. The arrangement of the three Cu atoms is triangular, with distances of 3.365(1) A between the central and terminal Cu atoms. The coppers are pentacoordinated; the coordination geometry is tetrahedral distorted square pyramidal for the terminal Cu atoms and elongated square pyramidal for the central Cu atom. Two hydroxo ligands and two of the four isonicotinato N-oxide ligands throu…