Corrigenda - Complexes of binucleating ligands. III. Novel complexes of a macrocyclic binucleating ligand

1970 ◽  
Vol 23 (11) ◽  
pp. 2225 ◽  
Author(s):  
NH Pilkington ◽  
R Robson
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Organic Ligand ◽  
Structural Features ◽  
Crystallographic Analysis ◽  
Metal Salts ◽  
X Ray ◽  
Spectral Evidence ◽  
Binucleating Ligands

By reaction of 5-methylisophthalaldehyde with 1,3-diaminopropane in the presence of various metal salts the following complexes have been isolated: MCu2Cl2,6H2O, MCu2(ClO4)2,2H2O, MCu2(HSO4)2,H2O, MNi2Cl2,2H2O, MCo2Cl2,2CH3OH, MFezCl2,2CH3OH, MMn2Cl2,2H2O, MZn2Cl2,2H2O, (MH2)Ni(ClO4)2,2H2O where MH2 represents the macrocyclic tetrakis-Schiff base obtained by condensation of two molecules each of the diamine and dialdehyde components and M represents the derived dianion which behaves as a novel macrocyclic binucleating ligand. On the basis of magnetic and spectral evidence the complexes are assigned binuclear structures in which the cations are in an approximately square-pyramidal environment. These structural features have been confirmed in the case of MCu2Cl2,6H2O by an independently conducted X-ray crystallographic analysis. It is suggested that (MH2)Ni(ClO4)2,H2O is closely related to the others in that the nickel environment is square-pyramidal and that essentially the same organic ligand framework is present, with two protons rather than a metal ion occupying the second cavity of M.

Complexes of binucleating ligands. III. Novel complexes of a macrocyclic binucleating ligand

1970 ◽  
Vol 23 (11) ◽  
pp. 2225 ◽  
Author(s):  
NH Pilkington ◽  
R Robson
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Organic Ligand ◽  
Structural Features ◽  
Crystallographic Analysis ◽  
Metal Salts ◽  
X Ray ◽  
Spectral Evidence ◽  
Binucleating Ligands

By reaction of 5-methylisophthalaldehyde with 1,3-diaminopropane in the presence of various metal salts the following complexes have been isolated: MCu2Cl2,6H2O, MCu2(ClO4)2,2H2O, MCu2(HSO4)2,H2O, MNi2Cl2,2H2O, MCo2Cl2,2CH3OH, MFezCl2,2CH3OH, MMn2Cl2,2H2O, MZn2Cl2,2H2O, (MH2)Ni(ClO4)2,2H2O where MH2 represents the macrocyclic tetrakis-Schiff base obtained by condensation of two molecules each of the diamine and dialdehyde components and M represents the derived dianion which behaves as a novel macrocyclic binucleating ligand. On the basis of magnetic and spectral evidence the complexes are assigned binuclear structures in which the cations are in an approximately square-pyramidal environment. These structural features have been confirmed in the case of MCu2Cl2,6H2O by an independently conducted X-ray crystallographic analysis. It is suggested that (MH2)Ni(ClO4)2,H2O is closely related to the others in that the nickel environment is square-pyramidal and that essentially the same organic ligand framework is present, with two protons rather than a metal ion occupying the second cavity of M.

scholarly journals Investigating valence tautomerism presence in compounds of Co and naphthoquinone

2014 ◽  
Vol 70 (a1) ◽  
pp. C1257-C1257
Author(s):  
Marcos Ribeiro ◽  
Humberto Stumpf ◽  
Carlos Pinheiro
Keyword(s):  
Coordination Compounds ◽  
Metal Ion ◽  
Organic Ligand ◽  
Electronic States ◽  
Functional Materials ◽  
Structural Features ◽  
X Ray Diffraction ◽  
Valence Tautomerism ◽  
X Ray ◽  
Vis Spectroscopy

The search for new functional materials involves the development of bistable molecules exhibiting different electronic states with distinct properties at the ambient condition (temperature, pressure, illumination) of application. Coordination compounds, which present electron transfer between metal ion and an organic ligand associated with a change in electron multiplicity of the metal ion, are named valence tautomers(VT)[1]. The chemical equilibrium between two distinct electronic states in VT can be induced by temperature and pressure change as well as by soft X-ray and light irradiation. Thermodynamic and structural data highlighting the mechanisms of the valence tautomerism interconversion can be found in the literature for materials build up with cobalt and benzoquinones such as the 3,5-di-t-butyl-semiquinonate. However, to the best of our knowledge, there is no example of compounds showing VT build up with cobalt and naphthoquinones. In the present work 2-hydroxy-1,4-naphthoquinone (law) has been used as redox active ligands in the search for new VT compounds with cobalt. Three new coordination compounds of cobalt and 2-hydroxy-1,4-naphthoquinone (law), [Co(law)2(im)2], [Co(law)2(phen)] e [Co(law)2(bpy)] were synthesized and characterized by infrared (IR), UV-vis spectroscopy, electron paramagnetic resonance (EPR) and cyclic voltammetry. The three dimensional structures were determined using single crystal X-ray diffraction techniques. However, within the investigated temperature range neither X-ray diffraction nor EPR data showed the presence of VT in the materials, mainly due to the electrochemical properties of the 2-hydroxy-1,4-naphthoquinone. Nevertheless the structural features of the compounds as well as their supramolecular packing motifs suggest that naphthoquinones can be an alternative for the synthesis of compounds showing valence tautomerism[3].

Hexa Schiff-base cryptands: solution thermodynamic and X-ray crystallographic studies of main group, transition and heavy metal ion complexes

1996 ◽  
pp. 2747-2755 ◽  
Author(s):  
Rym Abidi ◽  
Françoise Arnaud-Neu ◽  
Michael G. B. Drew ◽  
Sarah Lahély ◽  
Debbie Marrs ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Schiff Base ◽  
Metal Ion ◽  
Main Group ◽  
Heavy Metal Ion ◽  
Metal Ion Complexes ◽  
X Ray

Two new zinc(II) and mercury(II) complexes based on N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide): synthesis, crystal structures and antibacterial activities

2020 ◽  
Vol 76 (5) ◽  
pp. 476-482
Author(s):  
Al-Ameen Bariz OmarAli ◽  
Ahmed Jasim M. Al-Karawi ◽  
Adil A. Awad ◽  
Necmi Dege ◽  
Sevgi Kansız ◽  
...  
Keyword(s):  
Organic Ligand ◽  
Antibacterial Activities ◽  
Structural Features ◽  
Bacterial Strains ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Growth Inhibitory ◽  
The Difference

Reaction of N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide), C20H18F2N4O2, (LF ), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ2 N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], (1), and dichlorido[N,N′-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ4 O,N,N′,O′]mercury(II), [HgCl2(C20H18F2N4O2)], (2). The organic ligand and its metal complexes are characterized using various techniques: IR, UV–Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X-ray diffraction (PXRD), single-crystal X-ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex (1), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in (2) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth-inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.

scholarly journals Synthesis, Characterization, and Catalytic Studies of Mn(III)-Schiff Base-Dicyanamide Complexes: Checking the Rhombicity Effect in Peroxidase Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Manuel R. Bermejo ◽  
Rocío Carballido ◽  
M. Isabel Fernández-García ◽  
Ana M. González-Noya ◽  
Gustavo González-Riopedre ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Solid State ◽  
Elemental Analysis ◽  
Self Assembly ◽  
Metal Ion ◽  
Water Soluble ◽  
Intramolecular Interactions ◽  
X Ray ◽  
Peroxidase Mimics

The condensation of 3-methoxy-2-hydroxybenzaldehyde and the diamines 1,2-diphenylendiamine, 1,2-diamine-2-methylpropane and 1,3-propanediamine yielded the dianionic tetradentate Schiff base ligands N,N′-bis(2-hydroxy-4-methoxybenzylidene)-1,2-diphenylendiimine (H2L1), N,N′-bis(2-hydroxy-4-methoxybenzylidene)-1,2-diamino-2-methylpropane (H2L2) and N,N′-bis(2-hydroxy-4-methoxybenzylidene)-1,3-diaminopropane (H2L3) respectively. The organic compounds H2L1 and H2L2 have been characterized by elemental analysis, IR, 1H and 13C NMR spectroscopies and mass spectrometry electrospray (ES). The crystal structure of H2L2 in solid state, solved by X-ray crystallography, is highly conditioned in the solid state by two N-H•••N intramolecular interactions. The synthesis of three new manganese(III) complexes 1–3, incorporating these ligands, H2L1–H2L3, and dicyanamide (DCA), is reported. The complexes 1–3 have been physicochemically characterized by elemental analysis, IR and paramagnetic 1H NMR spectroscopy, ESI mass spectrometry, magnetic moment at room temperature and conductivity measurements. Complex 1 has been crystallographically characterized. The X-ray structure shows the self-assembly of the Mn(III)-Schiff base-DCA complex through µ-aquo bridges between neighbouring axial water molecules and also by π-π stacking interactions, establishing a dimeric structure. The manganese complexes were also tested as peroxidase mimics for the H2O2-mediated reaction with the water-soluble trap ABTS, showing complexes 1-2 relevant peroxidase activity in contrast with 3. The rhombicity around the metal ion can explain this catalytic behaviour.

scholarly journals Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
J. Senthil Kumaran ◽  
S. Priya ◽  
N. Jayachandramani ◽  
S. Mahalakshmi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Metal Ion ◽  
Biological Activities ◽  
Bacterial Species ◽  
Spectroscopic Characterization ◽  
Structural Features ◽  
Fungal Species ◽  
Spectral Studies ◽  
Central Metal

A new series of Cu (II), Ni (II), Co (II) and Zn (II) complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis,1H-NMR,13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–HO and C–HN hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such asBacillus subtilis, Staphylococcus aureus, Proteus vulgarisand fungal species such asCandida albicansby thewell-diffusionmethod.

M[P(1,2-O2C6H4)3] (M = K or Na) — Synthesis, characterization, and use in halide abstraction

2012 ◽  
Vol 90 (7) ◽  
pp. 574-583 ◽  
Author(s):  
Paul W. Siu ◽  
Derek P. Gates
Keyword(s):  
Crystal Structure ◽  
Alkali Metal ◽  
Crystallographic Analysis ◽  
Molecular Structures ◽  
The Other ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Phosphate Anion ◽  
X Ray ◽  
Outside Diameter

Alkali metal salts of the tris(o-phenylenedioxy)phosphate anion, K[P(1,2-O2C6H4)3] (K[1]) and Na[P(1,2-O2C6H4)3] (Na[1]), were prepared by treating Et3NH[1] with KH or NaH, respectively. X-ray crystallographic analysis of K[1], crystallized in the presence of DMSO, revealed a dimeric structure of formulation K2(DMSO)6[1]2·C7H8. In contrast, the crystal structure of K[1] grown from MeCN consists of fascinating hexagonal macrocycles with formulation {K(MeCN)2[1]}6 with an outside diameter of about 25 Å and a very small hole (≤2.5 Å). Remarkably, these hexagonal macrocycles stack one upon the other with a spacing of about 9.4 Å. The salt, K[1], is an effective halide abstraction agent reacting with (dppp)PdCl2 (dppp = 1,3-bis(diphenylphosphino)propane) (1:1 ratio) or [(cod)RhCl]2 (2:1 ratio) to afford [(dppp)Pd(µ-Cl)]2[1]2 and (cod)Rh[1], respectively. The molecular structures of each complex were determined.

Metal ion controlled ring contraction to produce an oxazolidine-containing Schiff base macrocycle and the X-ray structure of the Pb(NCS)2 complex

1983 ◽  
pp. 1463 ◽  
Author(s):  
Neil A. Bailey ◽  
David E. Fenton ◽  
Ian T. Jackson ◽  
Richard Moody ◽  
Cecilia Rodriguez de Barbarin
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Ring Contraction ◽  
X Ray

scholarly journals Crystallization and preliminary X-ray crystallographic analysis of a novel α-L-arabinofuranosidase (CtGH43) fromClostridium thermocellumATCC 27405

2014 ◽  
Vol 70 (5) ◽  
pp. 616-618 ◽  
Author(s):  
Arun Goyal ◽  
Shadab Ahmed ◽  
Carlos M. G. A. Fontes ◽  
Shabir Najmudin
Keyword(s):  
Glycoside Hydrolase ◽  
Clostridium Thermocellum ◽  
Metal Ion ◽  
Crystallographic Analysis ◽  
Molecular Replacement ◽  
X Ray ◽  
Monoclinic Form ◽  
Cubic Form ◽  
Complete Breakdown ◽  
Metal Ion Affinity Chromatography

The truncated carbohydrate-active enzyme belonging to family 43 glycoside hydrolase fromClostridium thermocellum(CtGH43) is an α-L-arabinofuranosidase that in combination with endoxylanase leads to complete breakdown of L-arabinosyl-substituted xylans. The recombinant enzymeCtGH43 fromC. thermocellumwas overexpressed inEscherichia coliand purified by immobilized metal-ion affinity chromatography. The recombinantCtGH43 has a molecular mass of 35.86 kDa. Preliminary structural characterization was carried out onCtGH43 crystallized from different conditions, which gave either cube-shaped or brick-shaped crystals. These diffracted to a resolution of 1.65 Å for the cubic form and 1.1 Å for the monoclinic form. Molecular replacement was used to solve theCtGH43 structure.

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