New Square-Planar Bis(Dithiolene) Complexes: Synthesis, Crystallography, and Properties of [Bu4N][MIII(btdt)2] (M=Cu, Au) and [Bu4N]2[PtII(btdt)2] ({btdt}2 - =2,1,3-Benzenethiadiazole-5,6-dithiolate)

2011 ◽  
Vol 64 (5) ◽  
pp. 550 ◽  
Author(s):  
Ramababu Bolligarla ◽  
Samar K. Das
Keyword(s):  
Metal Ion ◽  
Visible Region ◽  
Solvent Polarity ◽  
Planar Geometry ◽  
Central Metal ◽  
Absorption Bands ◽  
Space Groups ◽  
Square Planar ◽  
Structures And Properties ◽  
Intermolecular Contacts

The syntheses, crystal structures, and properties of three new coordination complexes [Bu4N][MIII(btdt)2] [M = Cu (1), Au (2)] and [Bu4N]2[PtII(btdt)2] (3) ({btdt}2– = 2,1,3-benzenethiadiazole-5,6-dithiolate) are described. Compounds 1–3 crystallize in a triclinic P-1, and monoclinic P2(1)/c and C2/c space groups, respectively. The {MS4} chromophore lies in almost a square-planar coordination environment in complex 1, but has a slightly distorted square-planar geometry around the central metal ion in compounds 2 and 3. Interactions in the solid state have been studied by intermolecular contacts, in particular, compounds 2 and 3 have been characterized by S⋅⋅⋅N and S⋅⋅⋅S non-covalent interactions among dithiolate complexes, resulting in two- and one-dimensional supramolecular motifs, respectively. Complexes 1–3 show broad absorption bands in the visible region, with that of 3 being sensitive to solvent polarity. Complex 1 exhibits a very low reduction potential for a CuIII-coordination complex, while the PtII complex 3 shows two irreversible oxidative responses at 0.45 V and 0.74 V versus Ag/AgCl, respectively.

scholarly journals Crystal structures of [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O containing MnO6+1capped trigonal prisms and [Cu(Hspar)2](bdc)·2H2O containing CuO4squares (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate)

2016 ◽  
Vol 72 (1) ◽  
pp. 96-101
Author(s):  
Zhe An ◽  
Jing Gao ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Crystal Structures ◽  
Metal Ion ◽  
Three Dimensional ◽  
Trigonal Prism ◽  
Planar Geometry ◽  
Cationic Complex ◽  
Counter Ion ◽  
Square Planar

The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′)bis(sparfloxacin-κ2O,O′)manganese(II) dihydrate, [Mn(C8H4O4)(C19H22F2N4O3)2(H2O)0.25]·2H2O or [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O, (I), and bis(sparfloxacin-κ2O,O′)copper(II) benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O3)2](C8H4O4)·2H2O or [Cu(Hspar)2](bdc)·2H2O, (II), are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate). The Mn2+ion in (I) is coordinated by twoO,O′-bidentate Hspar neutral molecules (which exist as zwitterions) and anO,O′-bidentate bdc dianion to generate a distorted MnO6trigonal prism. A very long bond [2.580 (12) Å] from the Mn2+ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II), the Cu2+ion lies on a crystallographic inversion centre and a CuO4square-planar geometry arises from its coordination by twoO,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I) and (II) feature intramolecular N—H...O hydrogen bonds, which closeS(6) rings. In the crystals of both (I) and (II), the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

scholarly journals Nickel(II)-Based Building Blocks with Schiff Base Derivatives: Experimental Insights and DFT Calculations

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5316
Author(s):  
Néstor Novoa ◽  
Carolina Manzur ◽  
Thierry Roisnel ◽  
Samia Kahlal ◽  
Jean-Yves Saillard ◽  
...  
Keyword(s):  
Schiff Base ◽  
General Formula ◽  
Metal Ion ◽  
Density Functional ◽  
Building Blocks ◽  
Switching Behavior ◽  
Planar Geometry ◽  
Centrosymmetric Dimer ◽  
Square Planar ◽  
Tridentate Schiff Base

We have recently reported a series of neutral square planar tridentate Schiff base (L) complexes of the general formula [(L)M(py)], showing relatively high first-order hyperpolarizabilities and NLO redox switching behavior. In the present study, new members of this family of compounds have been prepared with the objective to investigate their potential as building blocks in the on-demand construction of D-π-A push–pull systems. Namely, ternary nickel(II) building blocks of general formula [(LA/D)Ni(4-pyX)] (4–7), where LA/D stands for an electron accepting or donating dianionic O,N,O-tridentate Schiff base ligand resulting from the monocondensation of 2-aminophenol or its 4-substituted nitro derivative and β-diketones R-C(=O)CH2C(=O)CH3 (R = methyl, anisyl, ferrocenyl), and 4-pyX is 4-iodopyridine or 4-ethynylpyridine, were synthesized and isolated in 60–78% yields. Unexpectedly, the Sonogashira cross-coupling reaction between the 4-iodopyridine derivative 6 and 4-ethynylpyridine led to the formation of the bis(4-pyridyl) acetylene bridged centrosymmetric dimer [{(LD)Ni}2(µ2-py-C≡C-py)] (8). Complexes 4–8 were characterized by elemental analysis, FT-IR and NMR spectroscopy, single crystal X-ray diffraction and computational methods. In each compound, the four-coordinate Ni(II) metal ion adopts a square planar geometry with two nitrogen and two oxygen atoms as donors occupying trans positions. In 8, the Ni…Ni separation is of 13.62(14) Å. Experimental results were proved and explained theoretically exploiting Density Functional Theory calculations.

scholarly journals Metal Complexes of π-Expanded Ligand (7): Syntheses, Structures and Properties of Pt(II) Complexes Containing the Isomeric 1- and 2-Alkyliminomethyl Pyrene Ligands

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 476 ◽  
Author(s):  
Xuan-Dien Luong ◽  
Xuan-Truong Nguyen
Keyword(s):  
Molecular Structure ◽  
Planar Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pt Complex ◽  
Physico Chemical ◽  
Clear Explanation ◽  
Square Planar ◽  
Structures And Properties ◽  
The Relationship

A [O,N] bidentate π-expanded ligand system, (E)-1-(n-octylimino)methylpyren-2-ol (2), was newly synthesized via a six-step synthesis from pyrene. The ligand 2 reacts with [PtCl2(PhCN)2] in chlorobenzene and the presence of a base at reflux for 2 h under the formation of (2(Pt)) complex with a yield of 70%. The molecular structure of (2(Pt)), studied by common spectroscopic methods and X-ray diffraction, shows a square planar geometry with a trans-configuration of the ligands. The molecular structure, absorption spectra, electrochemical properties, and phosphorescence characteristics of the (2(Pt)) complex are discussed, emphasizing the comparison with those of the previously reported Pt complex (1(Pt)) containing the isomeric ligands of 2, (E)-2-(n-octylimino)methylpyren-1-ol. The DFT calculations of the two Pt complexes are carried out and exhibit a clear explanation of the relationship between their physico-chemical characteristics.

scholarly journals Mixed Ligand Complexes of Copper(II) and Cobalt(II) with Hydrazones Derivatives and ortho-Vanillin: Syntheses, Characterizations and Antimicrobial Activity

2019 ◽  
Vol 35 (6) ◽  
pp. 1722-1730
Author(s):  
Israa A. Alghamdi ◽  
Mohamed Abdelbaset ◽  
Ines El Mannoubi
Keyword(s):  
Metal Complexes ◽  
Antimicrobial Activities ◽  
Molar Conductance ◽  
Mixed Ligand ◽  
Planar Geometry ◽  
Central Metal ◽  
Bacterial Strains ◽  
Hydrazone Ligand ◽  
Metal Atoms ◽  
Square Planar

The purpose of this paper was to synthesis new mixed-ligand Cu(II) and Co(II) metal complexes utilizing bidentate and tridentate donor hydrazones derivatives as primary ligands and o-vanillin as co-ligand. The obtained compounds were characterized by elemental analysis, Infrared, UV-Vis., 1H-NMR, Mass spectra, molar conductance, thermal analysis and atomic absorption spectroscopy (ASS). Spectroscopic analysis results indicated that the hydrazone ligand (L1) behave as tridentate (ONO) and forms metal complexes having distorted square planar geometry. While the ligands (L2, L3 AND L4) behave as bidentate (NO) and forms metal complexes having octahedral geometry around the central metal atoms. The antimicrobial potentials were assessed for the ligand (L2) and its metal complexes only and were screened against six types of bacterial strains and one fungal strain. The antimicrobial activities results of the tested compounds showed enhanced activity of the complexes over their parent ligands.

Synthesis and Characterization of Palladium(II) Complexes with Substituted Dihydrobenzoimidazo Quinazoline Derivatives

2017 ◽  
Vol 13 (2) ◽  
pp. 1-15
Author(s):  
Rita Bhattacharjee Virupaiah Gayathri
Keyword(s):  
Metal Ion ◽  
Synthesis And Characterization ◽  
Planar Geometry ◽  
Conductivity Measurements ◽  
Spectral Techniques ◽  
Mass Spectral ◽  
Square Planar ◽  
Elemental Analyses ◽  
Quinazoline Derivatives

A series of palladium(II) halo complexes of the types [PdX 2 L 2 ].nH 2 O {n = 0, X = Cl, L = L 2 , L 4 and L 5 ; X = Br, L = L 2 ; n = 1, X = Cl, L = L 1 and L 3 } and Pd 2 X 4 L 3 [X = Br, L = L 1 , L 3 , L 4   and L 5 ] were prepared where L is 6-R-5,6- dihydrobenzoimidazo quinazoline (R-Diq; where R = ethyl: L 1 / n or i-propyl: L 2 , L 3 / n or i-butyl: L 4 , L 5 ) and characterized by elemental analyses, conductivity measurements, TGA, infrared, electronic, NMR and mass spectral techniques. Based    on these studies monomeric/dimeric structure with a square planar geometry around the metal ion was proposed for all the complexes. Some of the complexes were investigated for anti-microbial activity.

scholarly journals Synthesis, Structural Investigations and Antimicrobial Activities of Homo Binuclear Complexes Derived from 2-Amino-4-chlorophenol

2020 ◽  
Vol 32 (4) ◽  
pp. 759-764
Author(s):  
K. Savitha ◽  
S. Vedanayaki
Keyword(s):  
Metal Complexes ◽  
Magnetic Moment ◽  
Dna Cleavage ◽  
Metal Ion ◽  
Antimicrobial Activities ◽  
Molar Conductance ◽  
Azomethine Nitrogen ◽  
Planar Geometry ◽  
Binuclear Complexes ◽  
Central Metal

Co(II), Ni(II) and Cu(II) homo binuclear Schiff base metal complexes were synthesized from terephthalaldehyde and 2-amino-4-chlorophenol in methanol using template method. The structure of the ligand and its metal complexes were established by elemental, molar conductance, UV, magnetic moment, IR, 1H & 13C NMR, EPR, mass, thermal and PXRD. Molar conductance values showed that all complexes were non-electrolytic in nature. The IR spectral data provides the coordination of azomethine nitrogen and oxygen with central metal ion. UV, ESR and magnetic moment values suggest square planar geometry for Co(II), Ni(II) and Cu(II) complexes. TGA and DSC analysis data show the thermal stability of the ligand and its metal complexes. The crystalline nature of ligand and its metal complexes were investigated by powder-XRD. The DNA cleavage activities of all the complexes assayed on PUC18 DNA shows nuclease ability.

scholarly journals Crystal structure and Hirshfeld surface analysis of one-dimensional copper(II) coordination polymer incorporating succinate and tetramethylethylenediamine ligands

2020 ◽  
Vol 76 (7) ◽  
pp. 1038-1041
Author(s):  
Adnan M. Qadir ◽  
Sevgi Kansiz ◽  
Necmi Dege ◽  
Georgina M. Rosair ◽  
Turganbay S. Iskenderov
Keyword(s):  
Surface Analysis ◽  
Copper Nitrate ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Planar Geometry ◽  
Basic Solution ◽  
One Dimensional ◽  
Square Planar ◽  
Intermolecular Contacts ◽  
Polymeric Chains

The reaction of copper nitrate with succinic acid (succH) and N,N,N′,N′-tetramethylethylenediamine (TMEDA) in basic solution produces the complex catena-poly[[[(N,N,N′,N′-tetramethylethylenediamine-κ2 N,N′)copper(II)]-μ-succinato-κ2 O 1:O 4] tetrahydrate], {[Cu(C4H4O4)(C6H16N2)]·4H2O} n or {[Cu(succ)(tmeda)]·4H2O} n . Each carboxylate group of the succinate ligand coordinates to a CuII atom in a monodentate fashion, giving rise to a distorted square-planar geometry. The succinate ligands bridge the CuII centres, forming one-dimensional polymeric chains. Hydrogen bonds between the ligands and water molecules link these chains into sheets that lie parallel to the ac plane. Hirshfeld surface analysis, d norm and two-dimensional fingerprint plots were examined to verify the contributions of the different intermolecular contacts within the supramolecular structure.

scholarly journals Synthesis, Spectroscopic, and Electrochemical Studies on Some New Copper(II) Complexes Containing 2-{[(Z)-Phenyl (Pyridine-2-yl) Methylidene] Amino}Benzenethiol and Monodentate Ligands

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. P. Rawat ◽  
M. Choudhary
Keyword(s):  
Cyclic Voltammetry ◽  
Metal Ion ◽  
Copper Complexes ◽  
Magnetic Moments ◽  
Planar Geometry ◽  
Spectroscopic Techniques ◽  
Electrochemical Studies ◽  
Square Planar ◽  
Monodentate Ligands ◽  
Tridentate Schiff Base

Five new mononuclear copper(II) complexes, namely, [Cu(L)(ImH)]·ClO41; [Cu(L)(Me-ImH)]·ClO42; [Cu(L)(Et-ImH)]·ClO43; [Cu(L)(2-benz-ImH)]·ClO44; [Cu(L)(benz-ImH)]·ClO45, where HL = 2-{[(Z)-phenyl (pyridine-2-yl) methylidene] amino} benzenethiol; ImH = Imidazole; Me-ImH = Methy-limidazole; Et-ImH = Ethyl-imidazole; 2-benz-ImH = 2-methyl-benzimidazole; benz-ImH = benz-imidazole, have been synthesized and characterized by various physicochemical and spectroscopic techniques. Magnetic moments, electronic spectra, and EPR spectra of the complexes suggested a square planar geometry around Cu(II) ion. The synthesized HL ligand behaves as monobasic tridentate Schiff base bound with the metal ion in a tridentate manner, with N2S donor sites of the pyridine-N, azomethine-N, and benzenethiol-S atoms. The redox behaviour of the copper complexes has been studied by cyclic voltammetry. Superoxide dismutase activity of these complexes has been revealed to catalyse the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed.

The physical basis of mineral optics I. Classical theory

1978 ◽  
Vol 42 (321) ◽  
pp. 19-30 ◽  
Author(s):  
R. G. J. Strens ◽  
Robert Freer
Keyword(s):  
Metal Ion ◽  
Visible Region ◽  
Ultra Violet ◽  
General Rule ◽  
Great Majority ◽  
Closed Shell ◽  
Transition Metal Ions ◽  
Open Shell ◽  
Absorption Bands ◽  
Helmholtz Equations

SummaryThe Helmholtz dispersion equations have been rewritten in a form that enables the optical constants of both transparent and opaque media to be calculated from their spectra. Both Helmholtz equations are used to describe the optical properties of opaque media, and to obtain values of reflectance, refractive index, and absorption coefficient. The Sellmeier dispersion equation is a special case of the dispersive Helmholtz equation applicable to weakly absorbing media (including the great majority of minerals studied in thin section): it is used to derive the wavelength-, composition-, direction-, and volume-dependence of the principal indices in mixed crystals of monoclinic or higher symmetry. The treatment can be extended to triclinic crystals.The birefringence of transparent phases is the expression in the visible region of the pleochroism of absorption bands in the ultra-violet. The bireflectance of opaque phases depends also upon the pleochroism of bands in the visible and near infra-red, resulting in extreme sensitivity of the optics of opaque materials to changes in wavelength, composition, and structure. The optical anisotropy of both transparent and opaque phases may be calculated if the dependence of the spectra on structure can be established by measurement or by calculation from structure data. The quantitative application of Bragg's method is restricted to phases of very simple chemistry and structure (e.g. calcite and rutile), but it may be applied qualitatively to rationalize the optic orientations of phases containing only closed-shell ions of neon or argon configuration, including many pyroxenes, amphiboles, micas, and chain aluminosilicates. When open-shell (transition metal) ions enter the structure, the general rule is that the anisotropy becomes more closely related to the distortion of the coordination polyhedron about the metal ion, and for ions of formal charge ≥ 3, this source of anisotropy is usually dominant.

scholarly journals Synthesis, spectral characterization, redox and antimicrobial activity of Schiff base transition metal(II) complexes derived from 4-aminoantipyrine and 3-salicylideneacetylacetone

2005 ◽  
Vol 3 (3) ◽  
pp. 537-555 ◽  
Author(s):  
Natarajan Raman ◽  
Chinnathangavel Thangaraja ◽  
Samuelraj Johnsonraja
Keyword(s):  
Antimicrobial Activity ◽  
Magnetic Susceptibility ◽  
Schiff Base ◽  
Transition Metal ◽  
Metal Ion ◽  
Free Ligand ◽  
Transition Metal Ions ◽  
Planar Geometry ◽  
Cyclic Voltammogram ◽  
Central Metal

AbstractA novel tetradentate N2O2 type Schiff base, synthesized from 1-phenyl-2,3-dimethyl-4-aminopyrazol-5-one(4-aminoantipyrine) and 3-salicylidene-acetylacetone, forms stable complexes with transition metal ions such as CuII, NiII, CoII and ZnII in ethanol. Microanalytical data, magnetic susceptibility, IR, UV-Vis.,1H-NMR, ESR and Mass spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-planar geometry around the central metal ion. These complexes show higher conductance values, supporting their electrolytic nature. The monomeric nature of the complexes was confirmed from their magnetic susceptibility values. Cyclic voltammogram of the copper(II) and nickel(II) complexes in DMSO solution at 300 K were recorded and the results are discussed. The X-band ESR spectra of the copper complex were recorded and the molecular orbital coefficient values were calculated from the spectra. The in vitro antimicrobial activities of the investigated compounds were tested against bacteria such as Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis and Escherichia coli and fungi like Aspergillus niger and Rhizoctonia bataicola. Most of the metal chelates show higher antimicrobial activity for the above microorganisms than that of the free ligand.

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