Solution and solid state studies of mixed ligand binuclear complexes containing one binucleating ligand

Stability constants of homobinuclear binary Cu(II) complexes of the dinucleating ligands, having equivalent coordination sites, 5,5′-methylene-bis-salicylaldehyde (H2A1), 5,5′-methylene-bis-(3-bromosalicylaldehyde) (H2A2), and 5,5′-methylene-bis-(3-nitrosalicylaldehyde) (H2A3), and mixed ligand Cu(II) complexes with one of the above ligands and bipyridyl (L1) or 1,10-phenanthroline (L2) as second ligand, have been determined potentiometrically in water:dioxane medium (50:50 and 30:70,v/v using a computer programme. The values of [Formula: see text] and [Formula: see text] have been compared within the series of complexes having different H2A and L. Probable explanations for the stability order have been extended. The complexes (Cu2AL2)(ClO4)2 have been isolated and characterized by elemental analysis, electronic and ESR spectral, and magnetic studies.

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Synthesis And Characterization Of Mixed Ligand Complexes Of Co(Ii) And Fe(Iii) Ions With Maleic Acid And Heterocyclic Amines

Journal of Bangladesh Chemical Society ◽

10.3329/jbcs.v25i2.15066 ◽

2013 ◽

Vol 25 (2) ◽

pp. 139-145 ◽

Cited By ~ 3

Author(s):

Md. Belayet Hossain ◽

M Saidul Islam ◽

M Rafiqul Islam ◽

Md. Abdus Salam ◽

M. Abu Yousuf

Keyword(s):

Elemental Analysis ◽

Maleic Acid ◽

Chemical Society ◽

Mixed Ligand ◽

Molecular Structures ◽

Heterocyclic Amines ◽

Mixed Ligand Complexes ◽

Synthesis And Characterization ◽

Magnetic Studies

This paper describes the preparation and characterization of mixed ligand complexes of Co(II) and Fe(III) ions with maleic acid and heterocyclic amines of general formula [M(ME)L] and K[M(ME)L] (where M = Co(II) (1-4), Fe(III) (5-6); ME = C4H2O4 (1-4), 2C4H2O4 (5-6); L = C5H6N2 (1), C9H7N (2-3), C9H6NO (4), C5H5N.H2O (5), C6H7N (6)). The molecular structures of the complexes have been determined by spectral, magnetic studies and elemental analysis. Journal of Bangladesh Chemical Society, Vol. 25(2), 139-145, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15066

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MIXED-LIGAND HETEROMETALLIC COMPLEXES OF Ge(IV)-M2+ (Mn, Fe, Co, Ni, Zn) WITH 1,3-DIAMINO-2-HYDROXYPROPANE N,N,N',N'-TETRAACETIC ACID

Odesa National University Herald Chemistry ◽

10.18524/2304-0947.2021.3(79).240751 ◽

2021 ◽

Vol 26 (3(79)) ◽

pp. 37-44

Author(s):

E. A. Chebanenko ◽

I. I. Seifullina ◽

E. E. Martsinko

Keyword(s):

Ir Spectra ◽

Elemental Analysis ◽

Diffuse Reflection ◽

Mixed Ligand ◽

Heterometallic Complexes ◽

Binuclear Complexes ◽

Tetraacetic Acid ◽

Absorption Bands ◽

Bidentate Coordination ◽

Wide Range

There have been developed a novel synthetic method that allowed to obtain raw of mixed-ligand heterometallic binuclear complexes of Ge(IV)-M2+ (Mn, Fe, Co, Ni, Zn) with 1,3-diamino‑2-hydroxypropane N, N, N’, N’-tetraacetic acid (H5hpdta). Compounds have been characterized by the set of methods: elemental analysis, thermogravimetry, IR‑spectroscopy, spectrum of diffuse reflection, magnetic suspensibility. According to the elemental analysis, the molar ratio Ge: M: H5hpdta: bipy= 1:1:1:1 in the obtained compounds 1‑5 corresponds to the formula [(H2O)(OH)Ge(m-hpdta)M(bipy)]·nН2О (M=Mn n=3 (1), Fe n=2 (2), Co n=4 (3), Ni n=4 (4), Zn n=3 (5). Complexes have yellow (1), red (2), orange (3), violet (4) and pink (5) colors and are stable on air. Compounds 1‑5 exist in the form of crystal hydrates, that contain certain amount of water molecules, that are eliminated into the gas phase while heating in the wide range of temperatures (t=80‑250 °C), which is accompanied with the low-temperature endothermic effect. This indicates the presence of a system of stable hydrogen bonds in their crystal structure. Analysis of the IR‑spectra 1‑5 revealed that form and coordination of ligands is similar. Deprotonation of all carboxylic groups in the ligands (H5hpdta) and their bonding to germanium and d-metal is confirmed with the absence in the IR‑spectra 1‑5 absorption bands characteristic for the free СООН H5hpdta (1716 сm‑1) and nas(СОО-) і ns(СОО-) bands. Disappearance of the ν(С-OН)-1210 сm‑1 and appearance of the ν(С-O)alk., νas(Ge-O-M), νs(Ge-O- M) absorption band indicates that OH‑group of H5hpdta is deprotonated and performs bridging function. 2,2`-bipyridine bidentatly coordinates to the d-metal, binds to the O, N‑atoms of hpdta5- ligand and reaches coordination number 6. The last ligand plays the bringing role between Ge-dmetal, shows itself as ditopic, octadentate in total. According to the magnetic moments of 3, 4 and their diffuse reflection spectra, polyhedrons of Co (II), Ni (II) are octahedrons, which are realized due to the bidentate coordination of bipyridine and four bonds with nitrogen and oxygen of hpdta5-. Structure of heterometallic binuclear complexes 1‑5 is similar. Ligand hpdta5- shows itself as octadentate ditopic, all carboxylate groups monodentatly coordinate to metals, oxygen atom of the deprotonated OH‑group performs the bridging function.

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Synthesis, Spectral and Antimicrobial Investigation of 2-(Naphthalenel-ylamino)-2- Phenylacetonitrile and 1, 10-Phenanthroline with Five Divalent Transition Metal Ions

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.1.6 ◽

2019 ◽

Vol 10 (01) ◽

Author(s):

Mohammed Al-Amery1 ◽

Ashraf Saad Rasheed ◽

Dina A. Najeeb

Keyword(s):

Transition Metal ◽

Metal Ions ◽

Transition Metal Ions ◽

Molar Conductance ◽

Octahedral Geometry ◽

Mixed Ligand ◽

Gram Negative Bacteria ◽

Magnetic Studies ◽

Gram Positive Bacteria

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.

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Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

Current Drug Metabolism ◽

10.2174/1389200221666200421122147 ◽

2020 ◽

Vol 21 (3) ◽

pp. 211-220 ◽

Cited By ~ 1

Author(s):

Chandrasai Potla Durthi ◽

Madhuri Pola ◽

Satish Babu Rajulapati ◽

Anand Kishore Kola

Keyword(s):

Solid State ◽

Solid State Fermentation ◽

Food Industry ◽

Energy Requirement ◽

Production Studies ◽

Wide Range ◽

Hybridoma Technology ◽

Bacteria And Fungi ◽

The Stability ◽

Glutaminase Activity

Aim & objective: To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF). Overview: An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase. Conclusion: The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

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Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19871356 ◽

1987 ◽

Vol 52 (5) ◽

pp. 1356-1361

Author(s):

S. Abdel Rahman ◽

M. Elsafty ◽

A. Hattaba

Keyword(s):

Circular Dichroism ◽

Solid State ◽

Ir Spectra ◽

Chain Length ◽

Room Temperature ◽

Infrared Study ◽

Feature Characteristic ◽

C 50 ◽

The Stability ◽

Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

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Computational Studies of 4-Formylpyridinethiosemicarbazone and Structural and Biological Studies of Its Ni(II) and Cu(II) Complexes

Heteroatom Chemistry ◽

10.1155/2019/3507837 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Mydhili P. Sripathi ◽

Sireesha Berely ◽

Chittireddy Venkata Ramana Reddy

Keyword(s):

Elemental Analysis ◽

Radical Scavenging ◽

Molar Conductance ◽

Computational Studies ◽

Hydrolytic Cleavage ◽

Bacterial Strains ◽

Intercalative Mode ◽

Biological Studies ◽

Calf Thymus ◽

The Stability

To understand the stability, chelation behaviour, and biological activity of 4-Formylpyridinethiosemicarbazone (H4FPT), it is important to recognize its interactive geometry. Hence, computational studies on geometrically optimized structures of thione and thiol forms of H4FPT were performed. Binary metal complexes of the ligand, H4FPT (L) with the Ni(II) and Cu(II) metal ions (M), were synthesized and characterized by various spectroanalytical techniques as elemental analysis, molar conductance, magnetic susceptibility measurements, LC-MS, TGA, IR, UV-Visible, ESR, and powder XRD. Elemental analysis, LC-MS, and TGA studies indicate 1:2 (ML2) composition for mononuclear Ni(II) complex and 1:1 (ML) composition for dinuclear Cu(II) complex. Electronic absorption titrations, fluorescence quenching studies, and viscosity measurements suggest intercalative mode of binding of the complexes with calf thymus DNA (CT-DNA). These complexes also promote hydrolytic cleavage of plasmid pBR322. The ligand (H4FPT) and its complexes showed moderate-to-good activity against Gram-positive and Gram-negative bacterial strains. The DPPH radical scavenging studies showed antioxidant nature of both complexes.

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Electrical Conductivity of Chloro(phenyl)glyoxime and Its Co(II), Ni(II) and Cu(II) Complexes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20031233 ◽

2003 ◽

Vol 68 (7) ◽

pp. 1233-1242 ◽

Cited By ~ 6

Author(s):

Orhan Turkoglu ◽

Mustafa Soylak ◽

Ibrahim Belenli

Keyword(s):

Electrical Conductivity ◽

Temperature Dependence ◽

Electric Conductivity ◽

Crystal Structures ◽

Elemental Analysis ◽

Analysis Data ◽

Elemental Analysis Data ◽

The Stability ◽

Xrd Patterns ◽

Metal Ligand

Chloro(phenyl)glyoxime, a vicinal dioxime, and its Ni(II), Cu(II) and Co(II) complexes were prepared. XRD patterns of the complexes point to similar crystal structures. IR and elemental analysis data revealed the 1:2 metal-ligand ratio in the complexes. The Co(II) complex is a dihydrate. Temperature dependence of electrical conductivity of the solid ligand and its complexes was measured in the temperature range 25-250 °C; it ranged between 10-14-10-6 Ω-1 cm-1 and increased with rising temperature. The activation energies were between 0.61-0.80 eV. The Co(II) complex has lower electric conductivity than the Ni(II) and Cu(II) complexes. This difference in the conductivity has been attributed to differences in the stability of the complexes.

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Electrochemiluminescence Study of Europium (III) Complex with Coumarin3-Carboxylic Acid

International Journal of Photoenergy ◽

10.1155/2008/131702 ◽

2008 ◽

Vol 2008 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Stefan Lis ◽

Krzysztof Staninski ◽

Tomasz Grzyb

Keyword(s):

Aqueous Solution ◽

Spectral Analysis ◽

Energy Transfer ◽

Solid State ◽

Carboxylic Acid ◽

Elemental Analysis ◽

Aluminium Electrode ◽

The Eu

The europium (III) complex of coumarin-3-carboxylic acid (C3CA) has been prepared and characterized on the basis of elemental analysis, IR, and emission (photoluminescence and electrochemiluminescence) spectroscopy. The synthesised complex having a formula Eu was photophysically characterized in solution and in the solid state. Electrochemiluminescence, ECL, of the system containing the Eu(III)/C3CA complex was studied using an oxide-covered aluminium electrode. The goal of these studies was to show the possibility of the use of electrochemical excitation of the Eu(III) ion in aqueous solution for emission generation. The generated ECL emission was very weak, and therefore its measurements and spectral analysis were carried out with the use of cut-off filters method. The studies proved a predominate role of the ligand-to-metal energy transfer (LMET) in the generated ECL.

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