Search results for "coordination complex"
showing 10 items of 381 documents
Speciation of tin(II) in aqueous solution: thermodynamic and spectroscopic study of simple and mixed hydroxocarboxylate complexes
2013
This contribution reports the results of potentiometric and Mossbauer investigations on the formation, stability, and structure of binary and ternary mono- and binuclear complexes of Sn2+ with three hydroxocarboxylic ligands (namely L = tartrate, malate, and citrate) and chloride at T = 298.15 K in different ionic media and ionic strengths (0.15 and 1.00 mol dm−3 in NaCl(aq) and 1.00 mol dm−3 in NaNO3(aq)). The stability constants of various simple Sn i H j L (2+−) and mixed Sn i H j L k Cl (2+−−) species obtained in the different experimental conditions are reported, and various speciation diagrams of the simple and mixed systems are shown in different conditions. The sequestering ability …
ChemInform Abstract: Review: Solution Equilibria of Ternary Complexes Formed from Copper(II), Aliphatic Amines, and Bioligands
2014
This review provides a summary of the coordination chemistry of ligands in the ternary system: copper(II)–aliphatic amine–bioligand, where amine = ethylenediamine – En, diethylenetriamine – Dien, or N, N, N′, N″, N″-pentamethyldiethylenetriamine – Me5dien, and bioligand = selected amino acid, aminohydroxamic acid, or aminophosphonic acid, in aqueous solution. We would like to show the specific interactions of copper(II) in ternary systems in the context of complex equilibria chemistry.
ChemInform Abstract: Cryptand-Like Anion Receptors
2010
The design of supramolecular hosts for anions began with simple diaza bicycles, named katapinands, and has evolved over the last 40 years to a number of elegantly designed receptors capable of binding many different anions. About the same time the term cryptand appeared in reference to another bicyclic compound that was selective for alkaline-earth ions. Since the first report these simple bicycles, a vast arena of hosts has appeared, including acyclic, monocyclic, and other multicyclic supramolecular receptors. Studies of these systems have revealed considerable information about anion coordination chemistry, including the fact that many of these complexes mimic their transition-metal coro…
Cryptand-like anion receptors
2010
The design of supramolecular hosts for anions began with simple diaza bicycles, named katapinands, and has evolved over the last 40 years to a number of elegantly designed receptors capable of binding many different anions. About the same time the term cryptand appeared in reference to another bicyclic compound that was selective for alkaline-earth ions. Since the first report these simple bicycles, a vast arena of hosts has appeared, including acyclic, monocyclic, and other multicyclic supramolecular receptors. Studies of these systems have revealed considerable information about anion coordination chemistry, including the fact that many of these complexes mimic their transition-metal coro…
Group 13 complexes of dipyridylmethane, a forgotten ligand in coordination chemistry.
2015
The reactions of dipyridylmethane (dpma) with group 13 trichlorides were investigated in 1 : 1 and 1 : 2 molar ratios using NMR spectroscopy and X-ray crystallography. With 1 : 1 stoichiometry and Et2O as solvent, reactions employing AlCl3 or GaCl3 gave mixtures of products with the salt [(dpma)2MCl2](+)[MCl4](-) (M = Al, Ga) as the main species. The corresponding reactions in 1 : 2 molar ratio gave similar mixtures but with [(dpma)MCl2](+)[MCl4](-) as the primary product. Pure salts [(dpma)AlCl2](+)[Cl](-) and [(dpma)AlCl2](+)[AlCl4](-) could be obtained by performing the reactions in CH3CN. In the case of InCl3, a neutral monoadduct (dpma)InCl3 formed regardless of the stoichiometry emplo…
Studies on coordination compounds vii, chromatographic, thermoanalytical and spectroscopic studies on thermal decomposition of cadmium(II) and lead(I…
1982
On the basis of decomposition temperatures and infrared spectra, cadmium(II) and lead(II) bissalicylaldoximates were considered to havetrans andcis structures, respectively.
Group 14 Metalloles, Ionic Species and Coordination Compounds
2009
1 Introduction 2 Synthesis 3 Organic Chemical Properties of Group 14 Metalloles 4 Polymeric Silole-Containing π-Conjugated Systems 5 Ionic Species and Coordination Compounds 6 Addendum 7 Conclusion 8 Acknowledgements Keywords: five-membered heterocyclic dienes; heterocyclopentadienes - heteroles or metalloles; group 14 metalloles, ionic species and coordination compounds; gas-phase pyrolysis of silacyclopent-3-enes; organometallic dihalide reaction with dilithio reagent; group 14 metalloles; HOMO stabilization; polymeric silole-containing pi-conjugated systems
Synthesis, Structural, Magnetic and Thermal Characterization of {[Cu(bipy)] 2 (μ‐HP 2 O 7 )(μ‐Cl)}·H 2 O
2008
Copper(II) hydroxide reacts with 2,2′-bipyridine (bipy) and sodium pyrophosphate in a 2:2:1 stoichiometric ratio under ambient conditions at pH 1.6 in water. The resulting neutral dinuclear CuII complex features a bridging set containing bridging monoprotonated pyrophosphate and a monoatomic chloro bridge (making this the first pyrophosphate bridged coordination complex containing an alternate, additional halide bridge between the metal centers). Single-crystal X-ray diffraction studies revealed the complex to be {[Cu(bipy)]2(μ-HP2O7)(μ-Cl)}·H2O. The structure consists of a dimeric copper(II) system with each metal ion in a square pyramidal geometry. The asymmetric [Cu(bipy)]2+ units are br…
Syntheses, crystal structures and magnetic properties of tricyanomethanide-containing bis(2-pyrimidylcarbonyl)amidate copper(II) complexes
2008
Abstract Three new copper(II) complexes of formulae [Cu(bpcam)(tcm)(H2O)] · 2H2O (1), [Cu(bpcam)(tcm)(H2O)] (2) and [Cu(bpcam)(tcm)]n (3) [bpcam = bis(2-pyrimidylcarbonyl)amidate and tcm = tricyanomethanide] have been prepared and their structures determined by single crystal X-ray diffraction. Complexes 1 and 2 are mononuclear species where each copper atom is five-coordinated in a somewhat distorted square pyramidal environment with a tridentate bpcam ligand and a terminally bound tcm group building the basal plane and a water molecule in the apical position. Compound 3 is a uniform copper(II) chain where the [Cu(bpcam)]+ units are connected through single μ-1,5-tcm bridges which link one…
Helicate Extension as a Route to Molecular Wires
2008
We describe the preparation of a helicate containing four closely spaced, linearly arrayed copper(I) ions. This product may be prepared either directly by mixing copper(I) with a set of precursor amine and aldehyde subcomponents, or indirectly through the dimerization of a dicopper(I) helicate upon addition of 1,2-phenylenediamine. A notable feature of this helicate is that its length is not limited by the lengths of its precursor subcomponents: each of the two ligands wrapped around the four copper(I) centers contains one diamine, two dialdehyde, and two monoamine residues. This work thus paves the way for the preparation of longer oligo- and polymeric structures. DFT calculations and elec…