scholarly journals Synthetic, Spectral and Thermal Studies of Tin(IV) Complexes of 1, 5-Benzodiazepines

2008 ◽  
Vol 5 (3) ◽  
pp. 627-633 ◽  
Author(s):  
Suresh ◽  
Padaki Srinivas ◽  
T. Suresh ◽  
M. Revanasiddappa ◽  
Syed Khasim
Keyword(s):  
Metal Ion ◽  
Thermal Studies ◽  
Molar Conductance ◽  
Information Support ◽  
X Ray Diffraction ◽  
Cubic Crystal ◽  
Alcoholic Medium ◽  
X Ray ◽  
Simple Cubic ◽  
Infrared Spectral

Tin(IV) complexes of 7-substituted 6,7-benzo-1,5-dizepines have been synthesized in absolute alcoholic medium. Elemental analysis indicates that the complexes have 1:2 stoichiometry of the type L2SnCl4, TGA data support this conclusion. Molar conductance values in DMF at 10–3 M suggest that, these complexes are non-electrolytes. Infrared spectral data shows the involvement of C=N and NH groups in coordination with the metal ion. X-ray diffraction pattern of few representative complexes indicate that, these are having simple cubic crystal structure. The energy of activation and order of reaction are calculated using TGA data of the complexes. All these information support that Sn(IV) in these complexes exhibits coordination number eight.

Characterization of the adducts of bis(O-isoamyldithiocarbonato) nickel(II) with heterocyclic amines and X-ray structure of bis(O-isoamyldithiocarbonato)-bis(3-bromopyridine)nickel(II)

2016 ◽  
Vol 57 (8) ◽  
pp. 1688
Keyword(s):  
Magnetic Susceptibility ◽  
Spectral Data ◽  
Metal Ion ◽  
Diffraction Method ◽  
Bidentate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Infrared Spectral ◽  
Substituted Pyridines

A series of six-coordinated Ni(II) complexes, with the general formula Ni(Xan)L2 (where Xan = isoamyldithiocarbonato and L = 2-bromopyridine, 3-bromopyridine, 4-acetylpyridine, 3-hydroxypyridine and 2-methoxypyridine) are synthesized and characterized by the elemental analysis and various physicochemical techniques such as magnetic susceptibility and conductivity measurements, UV-visible and infrared spectral data. Based on the electronic spectra and magnetic susceptibility measurements, an octahedral geometry is proposed for all the complexes. IR spectral data show that in all these complexes substituted pyridines coordinate to the metal ion through nitrogen atoms occupying the fifth and sixth axial positions, whereas O-alkyldithiocarbonate acts as a monoanion bidentate ligand and occupies the planar positions of octahedral structures. The structure of the adduct with 3-bromopyridine is elucidated by the single crystal X-ray diffraction method. The complex crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.5855(4) Å, b = 9.4984(6) Å, c = 12.4518(8) Å, α = 87.944(5)°, β = 78.843(5)°, γ = 77.794(5)°. The crystal structure of the molecule is stabilized by intermolecular C—H…S and C—H…π interactions.

scholarly journals Synthesis and spectroscopic characterization of some lanthanide(III) nitrate complexes of 3-[3-carboxyethyl-4,5- dimethylthiophene-2-yl)azo]pent-2,4-dione

2011 ◽  
Vol 76 (2) ◽  
pp. 249-261 ◽  
Author(s):  
Janardhanan Athira ◽  
Yesodharan Sindhu ◽  
Susamma Sujamol ◽  
Kochukittan Mohanan
Keyword(s):  
Elemental Analysis ◽  
Metal Ion ◽  
Spectroscopic Characterization ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Structural Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrate Complexes

3-[3-Carboxyethyl-4,5-dimethylthiophene-2-yl)azo]pent-2,4-dione was synthesized by coupling diazotized 2-amino-3-carboxyethyl- 4,5-dimethylthiophene with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen bonded azoenol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III) complexes viz, lanthanum(III), cerium(III), praseodymium(III), neodymium(III), samarium(III) and gadolinium(III), which were characterized through various spectral studies, elemental analysis, magnetic susceptibility measurements, molar conductance and thermal analysis. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through one of the azo nitrogen atoms, the ester carbonyl and the enolic oxygen of the acetylacetone moiety, without deprotonation. Molar conductance values adequately supported their non-electrolytic nature. The ligand and lanthanum(III) complexes were subjected to X-ray diffraction studies. In addition, the lanthanum(III) complex underwent a facile transesterification reaction on refluxing with methanol for a long period. The thermal behavior of the lanthanum(III) complex was also examined.

scholarly journals Pyrene Carboxylate Ligand Based Coordination Polymers for Microwave-Assisted Solvent-Free Cyanosilylation of Aldehydes

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Polymer ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Solvent Free ◽  
Lewis Acidity ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.

scholarly journals Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  
Keyword(s):  
Water Content ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction of a lysine-specific permease fromPseudomonas aeruginosa

2014 ◽  
Vol 70 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Emmanuel Nji ◽  
Dianfan Li ◽  
Declan A. Doyle ◽  
Martin Caffrey
Keyword(s):  
Metal Ion ◽  
Cell Volume Regulation ◽  
Ion Concentration ◽  
Size Exclusion ◽  
Substrate Selectivity ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Exclusion Chromatography

The prokaryotic lysine-specific permease (LysP) belongs to the amino acid–polyamine–organocation (APC) transporter superfamily. In the cell, members of this family are responsible for the uptake and recycling of nutrients, for the maintenance of a constant internal ion concentration and for cell volume regulation. The detailed mechanism of substrate selectivity and transport of L-lysine by LysP is not understood. A high-resolution crystal structure would enormously facilitate such an understanding. To this end, LysP fromPseudomonas aeruginosawas recombinantly expressed inEscherichia coliand purified to near homogeneity by immobilized metal ion-affinity chromatography (IMAC) and size-exclusion chromatography (SEC). Hexagonal- and rod-shaped crystals were obtained in the presence of L-lysine and the L-lysine analogue L-4-thialysine by vapour diffusion and diffracted to 7.5 Å resolution. The diffraction data were indexed in space groupP21, with unit-cell parametersa= 169.53,b= 169.53,c= 290.13 Å, γ = 120°.

scholarly journals Synthesis, characterization, x-ray diffraction studies and biological activities of iron(III) and cobalt(II) complexes with alanine

2018 ◽  
Vol 6 (2) ◽  
pp. 132
Author(s):  
Shuaibu Musa ◽  
S O. Idris ◽  
A D. Onu
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Human Life ◽  
Molar Conductance ◽  
Biological Molecules ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Metal Ligands ◽  
Elemental Analyses

The resulted complexes produced between Fe (III) and Co (II) with biological molecules like amino acids play an important role in human life. They can be used as bioactive compounds as well as in industries. Fe (III) and Co (II) complexes are synthesized with Alanine amino acid. The complexes were characterized by X-ray diffraction, magnetic suscetivility, elemental analysis (AAS), molar conductance, melting point, infrared and uv-visible spectrophotometry analyses. The elemental analyses were used to determine the chelation ratio, 1:3(metal: ligands) for iron (III) Alanine and 1:2 ratio for cobalt (II) Alanine. The molar conductivity of the complexes show that the complexes are not electrolytic in nature. The x-ray data suggest monoclinic crystal system for all the complexes with the exception of Co-alanine, which is hexagonal. The magnetic susceptivility and electronic spectra suggest the complexes are high spin with octahedral geometry.The complexes show enhance activity in comparable to the amino acid.  

Fabrication and Microstructure of Ge-Sb-S-CsCl Chalcogenide Glass Containing β-GeS2 Nanocrystals

2014 ◽  
Vol 665 ◽  
pp. 119-123
Author(s):  
Ji Yan Hao ◽  
Hai Tao Liu
Keyword(s):  
Chalcogenide Glass ◽  
Spherical Shape ◽  
Orthorhombic Phase ◽  
Far Infrared ◽  
X Ray Diffraction ◽  
Base Glass ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared Spectral ◽  
Quenching Method

we report the fabrication and microstructure of Ge-Sb-S-CsCl chalcogenide glass containing β-GeS2 nanocrystals. A Ge-Sb-S-CsCl chalcogenide base glass with the better crystalline ability is first fabricated by melt-quenching method, and a further careful thermal process has led to the formation of β-GeS2 nanocrystals in the glass. Transmission electron microscopy showed that the size of β-GeS2 nanocrystals with nearly monodisperse spherical shape ranges from 30 to 45 nm in the glass. Powder X-ray diffraction results confirm that the β-GeS2 nanocrystals are of high crystallization with orthorhombic phase. Energy dispersive spectroscopy is employed for the information of nanocrystals glass composition. It is worthwhile to note that the obtained Ge-Sb-S-CsCl chalcogenide glass containing β-GeS2 nanocrystals still keeps higher transmittance in mid- and far- infrared spectral region.

scholarly journals Synthesis, Structure and Antitumour Properties of a New 1,2-Propylenediaminetetraacetate-Ruthenium(III) Compound

1995 ◽  
Vol 2 (4) ◽  
pp. 211-219 ◽  
Author(s):  
R. Vilaplana ◽  
M. A. Romero ◽  
M. Quirós ◽  
J. M. Salas ◽  
F. González-Vílchez
Keyword(s):  
Metal Ion ◽  
Antitumour Activity ◽  
Octahedral Geometry ◽  
X Ray Diffraction ◽  
Chlorine Atoms ◽  
X Ray ◽  
Human Cancers ◽  
Novel Complex

A novel complex formed by ruthenium (III) and the sequestering ligand 1,2-propylenediaminetetraacetic acid (PDTA) has been synthetized and characterized. The structure of the monomeric compound, studied by X-ray diffraction , shows an almost symmetric octahedral geometry around the metal ion, with two chlorine atoms in a cis conformation. The antitumour activity against a variety of murine and human cancers is reported.

scholarly journals Spin State Behavior of A Spin-Crossover Iron(II) Complex with N,N′-Disubstituted 2,6-bis(pyrazol-3-yl)pyridine: A Combined Study by X-ray Diffraction and NMR Spectroscopy

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 793
Author(s):  
Elizaveta K. Melnikova ◽  
Dmitry Yu. Aleshin ◽  
Igor A. Nikovskiy ◽  
Gleb L. Denisov ◽  
Yulia V. Nelyubina
Keyword(s):  
Nmr Spectroscopy ◽  
Spin State ◽  
Metal Ion ◽  
Spin Crossover ◽  
Molecular Design ◽  
Chemical Shifts ◽  
Variable Temperature ◽  
High Spin State ◽  
X Ray Diffraction ◽  
X Ray

A series of three different solvatomorphs of a new iron(II) complex with N,N′-disubstituted 2,6-bis(pyrazol-3-yl)pyridine, including those with the same lattice solvent, has been identified by X-ray diffraction under the same crystallization conditions with the metal ion trapped in the different spin states. A thermally induced switching between them, however, occurs in a solution, as unambiguously confirmed by the Evans technique and an analysis of paramagnetic chemical shifts, both based on variable-temperature NMR spectroscopy. The observed stabilization of the high-spin state by an electron-donating substituent contributes to the controversial results for the iron(II) complexes of 2,6-bis(pyrazol-3-yl)pyridines, preventing ‘molecular’ design of their spin-crossover activity; the synthesized complex being only the fourth of the spin-crossover (SCO)-active kind with an N,N′-disubstituted ligand.

Sign in / Sign up

Export Citation Format

Share Document