Search results for "Ordination"

A Three-Dimensional Homometallic Molecular Ferrimagnet

2002

Bimetallic cyanide-bridged complexes based on the photochromic nitroprusside anion and paramagnetic metal complexes

2001

Abstract Three novel compounds formed by the photochromic nitroprusside anion, [Fe(CN)5NO]2−, and the paramagnetic complexes [Cu(C19H18N6)]2+, [Ni(C6H14N2)2]2+ and [Ni(cyclam)]2+ are reported. The structure of [Cu(C19H18N6)][Fe(CN)5NO] (1) comprises binuclear complexes with a [Fe(CN)5NO]2− anion linked to a [Cu(C19H18N6)]2+ cation. The structure of [Ni(C6H14N2)2][Fe(CN)5NO]·6.5H2O (2) and [Ni(cyclam)][Fe(CN)5NO]·4H2O (3) consists of zigzag chains formed by an alternate array of the paramagnetic cations and [Fe(CN)5NO]2− anions. The three compounds are paramagnets; a fourth compound containing [cis-Ni(en)2]2+ cations and [Fe(CN)5NO]− anions does not show a change in the magnetic properties a…

Dicopper(II) Metallacyclophanes as Multifunctional Magnetic Devices: A Joint Experimental and Computational Study

2015

Metallosupramolecular complexes constitute an important advance in the emerging fields of molecular spintronics and quantum computation and a useful platform in the development of active components of spintronic circuits and quantum computers for applications in information processing and storage. The external control of chemical reactivity (electro- and photochemical) and physical properties (electronic and magnetic) in metallosupramolecular complexes is a current challenge in supramolecular coordination chemistry, which lies at the interface of several other supramolecular disciplines, including electro-, photo-, and magnetochemistry. The specific control of current flow or spin delocaliz…

Synthesis, Crystal Structure and Magnetic Properties of [Fe(bpe)4(H2O)2](TCNQ)2 (bpe = trans-1,2-bis(4-pyridyl)ethane and TCNQ = tetracyanoquinodimet…

2005

The synthesis, structure and magnetic properties of [Fe(bpe)4(H2O)2](TCNQ)2 (1) are reported. 1 crystallizes in the triclinic P space group, a = 13.481(5), b = 14.887(3), c = 16.663(4) A, α = 101.048(18), β = 112.84(2), γ = 90.92(2)°, V = 3009.6(14) A3, Z = 2. The iron atom defines a compressed octahedron with the equatorial positions occupied by the bpe molecules which act as monodentate ligands and the two axial positions occupied by water molecules. The TCNQ− radical counterions are uncoordinated and interact by pairs defining (TCNQ)22− units strongly coupled antiferromagnetically. The iron(II) atoms are in the high spin state and its magnetic behaviour indicates the occurrence of zero-f…

CuIIand ZnIICoordination Chemistry of Pyrazole‐Containing Polyamine Receptors − Influence of the Hydrocarbon Side Chain Length on the Metal Coordinat…

2004

The synthesis of a new macrocyclic receptor (L 4 ) containing two 3,5-dimethylpyrazole units connected by dipropylenetriamine bridges is reported for the first time; pH-metric titrations indicate that L 4 shows six protonation steps in the pH range 2-11. In the absence of metal ions, the pyrazole moieties are not involved in acid-base processes in this pH range. Addition of Cu I I and Zn I I results in deprotonation of the pyrazole moieties which act as bis(monodentate) η 1 :η 1 ligands. This induced deprotonation occurs at higher pH values than in the complexes of the analogous ligand containing diethylenetriamine bridges (L 1 ). The crystal structures of [Cu 2 (H - 2 L 4 )](ClO 4 ) 2 and …

Chemistry of the μ-hydridobis(pentacarbonylchromium(0)) species

1977

Abstract Reactions of the potassium and tetrabutylammonium derivatives of Cr 2 H(CO) 10 − , with N-donor bidentate ligands such as 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy) have been investigated. A coordination compound of general formula K[Cr 2 H(CO) 10 (phen) 3 ] is the most stable product from the reaction of the former with phen, but under certain conditions a 1 2 adduct may also be isolated. The analogous reaction with bpy leads to a single labile adduct, K[Cr 2 H(CO) 10 (bpy) 2 ]. (C 4 H 9 ) 4 N[Cr 2 H(CO) 10 (phen)] is formed by interaction of the latter derivative with phen, but bpy does not give the analogous adduct.

Copper complexes with dithiocarbamates derived from natural occurring amino acids. Crystal and molecular structure of [Cu(en)(EtOH)(H2O)3][Cu(dtc-pro…

2002

Abstract Reaction of Cu(II) salts with dithiocarbamates derived from the amino acids asparagine, glutamine, serine, threonine and tyrosine leads to reduction of the metallic cation and formation of Cu(I) complexes, whereas reaction with proline dithiocarbamate takes place without reduction, leading to formation of a Cu(II) coordination compound. Simultaneous reaction of proline dithiocarbamate and ethylenediamine with Cu(II) leads to the formation of the mixed complex [Cu(en)(EtOH)(H2O)3][Cu(dtc-pro)2]. In the anion, the Cu(II) centre possesses a D2h local symmetry, coordinated by two bidentate dithiocarbamate ligands, while the Cu(II) centre is in a distorted octahedral coordination in the…

Self-assembly of a chiral three-dimensional manganese(II)-copper(II) coordination polymer with a double helical architecture

2013

The use of the anionic dicopper(ii) complex, [CuII(mpba) 2]4- [mpba = N,N′-1,3-phenylenebis(oxamate)], as tetrakis(bidentate) metalloligand toward MnII ions in the presence of oxalate and the chiral (S)-trimethyl-(1-phenylethyl)ammonium cation affords the first example of a mixed oxalato/oxamato-based chiral 3D metal-organic polymer. © 2013 The Royal Society of Chemistry.

2,2′:6′,2″-Terpyridine Trimethylplatinum(IV) Iodide Complexes as Bifunctional Halogen Bond Acceptors

2016

Three new organometallic trimethylplatinum(IV) iodide complexes of 2,2′:6′,2″-terpyridines have been synthesized and characterized by 1H NMR spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray diffraction analysis. The X-ray crystal structures of PtMe3I(L) complexes 1–3 {L for 1 = 4′-chloro-2,2′:6′,2″-terpyridine, 2 = 4′-(4-cyanophenyl)-2,2′:6′,2″-terpyridine, and 3 = 4′-(4-tolyl)-2,2′:6′,2″-terpyridine} reveal distorted octahedral coordination geometry of the platinum(IV) metal centers with bidentate coordination of the terpyridine ligands. Complexation of 1–3 with iodopentafluorobenzene (IPFB) afforded single-crystal structures of halogen bond (XB) complexes 1a–3…

Coordination complexes incorporating pyrophosphate: Structural overview and exploration of their diverse magnetic, catalytic and biological properties

2010

Abstract Current attention continues to revolve around the chemistry and biochemistry associated with polyphosphate anions because of their importance in biology. A pivotal intermediate within this family is the pyrophosphate tetraanion, P2O74−. Considering its biological relevance and the multidentate nature that makes it an ideal ligand in the field of the coordination chemistry, there is a growing interest in the use of this anion in building new class of molecules/compounds for different purposes. While the total number of characterized structures still remains modest, several new pyrophosphate-containing coordination complexes have been reported in the last decade, as well as different…