Search results for "Amide"
showing 10 items of 3119 documents
Three one-dimensional systems with end-to-end dicyanamide bridges between copper(ii) centres: structural and magnetic properties
2002
The preparation, crystal structures and magnetic properties of three different copper(II) chains of formula [Cu(pyim)(H2O)(dca)]n(NO3)n (1), [Cu(dpa)(dca)2]n (2) and [Cu(bpa)(dca)2]n (3) [pyim = 2-(2-pyridyl)imidazole, dca = dicyanamide anion, dpa = 2,2′-dipyridylamine and bpa = 1,2-bis(4-pyridyl)ethane] are reported. A chain structure with single, symmetrical, end-to-end dca bridges is found in compound 1. This bridging mode, with two short, equatorially coordinated Cu–N bonds has not been previously observed in the [Cu(dca)Xn] (X = coligand) family of compounds. The copper atom in 1 has a distorted square pyramidal geometry with a bidentate pyim ligand and two nitrile nitrogen atoms from …
Syntheses, crystal structures and magnetic properties of copper(ii) dicyanamide complexes; dinuclear, chain and ladder compounds
2002
The preparation, crystal structures and magnetic properties of three heteroleptic copper(II) complexes with dicyanamide (dca) bridges, [Cu(bpca)(H2O)(dca)]2 (1) (bpca = bis(2-pyridylcarbonyl)amidate), [Cu(bpy)(dca)2]n (2) (bpy = 2,2′-bipyridine), [Cu2(bpm)(dca)4]n (3) (bpm = 2,2′-bipyrimidine) are reported. In addition, magnetic susceptibility measurements of the sheetlike polymer [Cu(phen)(dca)2] (4) (phen = 1,10-phenanthroline), structurally characterized previously, have been performed. In complex 1 pairs of mononuclear structural building blocks, [Cu(bpca)(dca)(H2O)], are loosely connected through a 1,3-dca bridge in which nitrile is equatorially bound and the amide is semi-coordinated …
2,2′-Bipyrimidine- and 2,3-bis(2-pyridyl)pyrazine-containing manganese(II) compounds: Structural and magnetic properties
2003
The preparation, crystal structures and magnetic properties of four different manganese(II) compounds of formula [Mn(bipym)Cl2]n·2nH2O (1), [Mn2(dpp)2(H2O)2Cl4]·2H2O (2), [Mn(dpp)(H2O)2]n(ClO4)2n·1.5nH2O (3) and [Mn(dpp)(dca)2]n (4) [bipym = 2,2′-bipyrimidine, dpp = 2,3-bis(2-pyridyl)pyrazine and dca = dicyanamide anion] are reported. Compounds 1 and 3 are uniform chains of six-coordinated manganese(II) ions bridged by bis(bidentate) bipym (1) and dpp (3) ligands with two chloride groups (1) and two water molecules (3) in cis position. The electroneutrality in 3 is achieved by uncoordinated perchlorate anions. The manganese atom in 1 and 3 exhibits a distorted octahedral environment mainly …
DNA binding, nuclease activity, DNA photocleavage and cytotoxic properties of Cu(II) complexes of N-substituted sulfonamides.
2013
Abstract Ternary copper(II) complexes [Cu(NST)2(phen)] (1) and [Cu(NST)2(NH3)2]·H2O (2) [HNST = N-(4,5-dimethylthiazol-2-yl)naphthalene-1-sulfonamide] were prepared and characterized by physico-chemical techniques. Both 1 and 2 were structurally characterized by X-ray crystallography. The crystal structures show the presence of a distorted square planar CuN4 geometry in which the deprotonated sulfonamide, acting as monodentate ligand, binds to the metal ion through the thiazole N atom. Both complexes present intermolecular π–π stacking interactions between phenanthroline rings (compound 1) and between naphthalene rings (compound 2). The interaction of the complexes with CT DNA was studied b…
[Cr(AA)(C2O4)2]− and [Cu(bpca)]+ as building blocks in designing new oxalato-bridged CrIIICuII compounds [AA=2,2′-bipyridine and 1,10-phenanthroline…
2003
Abstract The monouclear complex PPh4[Cr(bipy)(ox)2]·H2O (1) and the heterodinuclear compounds [Cu(bpca)(H2O)Cr(bipy)(ox)2]·2.5H2O (2) and [Cu(bpca)(H2O)Cr(phen)(ox)2]·2H2O (3) [PPh4+=tetraphenylphosphonium cation, bpca=bis(2-pyridylcarbonyl)amide anion, ox=oxalate dianion, bipy=2,2′-bipyridine and phen=1,10-phenanthroline] have been synthesized and characterized by single-crystal X-ray diffraction. Discrete [Cr(bipy)(ox)2]− mononuclear anions and tetraphenylphosphonium cations are present in 1 whereas the structures of 2 and 3 are made up neutral oxalato-bridged bimetallic CrIIICuII units. The chromium environment is distorted octahedral in the three complexes: two nitrogen atoms from a bi…
Designing dicyanamide bridged 1D molecular architecture from a mononuclear copper(II) Schiff base precursor: Syntheses, structural variations and mag…
2009
International audience; A new tridentate N2O donor Schiff base ligand [(C6H5C(OH)CHC(CH3)NCH2C5H4N)LH] was obtained by 1:1 condensation of benzoylacetone with 2-picolylamine and has been used to synthesise a mononuclear [CuLCl] (1) and an end-to-end dicyanamide bridged polynuclear {[Cu2(μ-L)2(μ2-1,5-(CN)2N)]ClO4}n (2) copper(II) complexes. The ligand, 1 and 2 were clearly characterised by elemental analysis, FT-IR, 1H NMR, UV–Vis spectral studies, electrochemical studies and in addition single crystal X-ray diffraction studies were performed for 1 and 2. The Schiff base ligand [LH] shows a significant variation in its coordination behaviour with copper(II) ion in absence and in presence of …
Synthesis, X-ray crystal structure and magnetic study of the 1D {[Cu(N,N-diethyl-1,2-ethanediamine)(μ1,5-dca)(dca)]}n complex
2007
Abstract A new complex, {[CuL(μ1,5-dca)(dca)]}n (1), has been synthesized from the reaction of Cu(NO3)2 · 3H2O, N,N-diethyl-1,2-ethanediamine (L) and sodium dicyanamide (Nadca) in aqueous medium. Single crystal X-ray analysis reveals that the complex has a 1D infinite zigzag chain structure in which copper(II) ions are bridged by single dicyanamide ligands in an end-to-end fashion. The chains propagate parallel to the crystallographic b-axis and they are stacked one upon another along the c-axis. The coordination environment of the copper(II) centers are distorted square-pyramidal. Of the four coordination sites of the basal plane of the square-pyramid, two are occupied by the nitrogen atom…
A Co(III) complex of carbonic anhydrase inhibitor methazolamide and the amino-imino ‘aib’ ligand formed by reaction of acetone and ammonia
1993
Abstract Reaction of Co(NO 3 ) 2 ·6H 2 O with methazolamide {[ N -(3-methyl-5-sulfamoyl-1,3,4-thiadiazol-2(3 H )-ylidene)acetamide] (Hmacm)} and ammonia in acetone to produce [Co(methazolamidate)(2-methyl-2-amino-4-iminopentane) 2 (NH 3 )](NO 3 ) 2 ·2H 2 O is described. The ligand 2-methyl-2-amino-4-iminopentane (aib) is the product obtained from the condensation of two ammonia and two acetone molecules. The complex crystallizes in the monoclinic space group P 2 1 / c with a =16.713(5), b =9.180(1), c =20.273(1) A, β=97.44(4)° for Z =4. The R value is 0.081 for 2150 significant reflections. The Co(III) ion exhibits a nearly regular octahedral arrangement with the CoN bond distances in the …
Multiple Roles of Isocyanides in Palladium-Catalyzed Imidoylative Couplings: A Mechanistic Study
2016
International audience; Kinetic, spectroscopic and computational studies examining a palladium-catalyzed imidoylative coupling highlight the dual role of isocyanides as both substrates and ligands for this class of transformations. The synthesis of secondary amides from aryl halides and water is presented as a case study. The kinetics of the oxidative addition of ArI with RNC-ligated Pd-0 species have been studied and the resulting imidoyl complex [(ArC=NR)Pd(CNR)(2)I] (Ar=4-F-C6H4, R = tBu) has been isolated and characterized by X-ray diffraction. The unprecedented ability of this RNC-ligated imidoyl-Pd complex to undergo reductive elimination at room temperature to give the amide in the p…
Microdisc-electrophoretic study of deoxyribonucleases in cow snout epidermis
1983
Acid and neutral deoxyribonucleases (DNases) of the cow snout epidermis were investigated by the microdisc-electrophoresis of polyacrylamide gels containing highly polymerized DNA and by isoelectric focusing techniques. The nucleases were characterized with respect to their pH optimum. An acid DNase at pH 5.0 was detected as a single distinct band after the electrophoretic separation. After isoelectric focussing also, only one acid DNase activity with an isoelectric point (IP) of 6.2 was detectable. Neutral DNases at pH 7.4 were demonstrated as major and minor bands by their different electrophoretic mobilities. In the isoelectric focusing system also, two neutral DNases, a major one (IP, 4…