Synthesis and Structural and Spectroscopic Characterization of a Complex between Co(II) and Imino-bis(methylphosphonic acid):  Gaining Insight into Biologically Relevant Metal−Ion Phosphonate Interactions or Looking at a New Co(II)−Organophosphonate Material?

The molecular oxygen produced in photosynthesis is generated via water oxidation at a manganese–calcium cluster called the oxygen-evolving complex (OEC). While studies in biophysics, biochemistry, and structural and molecular biology are well known to provide deeper insight into the structure and workings of this system, it is often less appreciated that biomimetic modelling provides the foundation for interpreting photosynthetic reactions. The synthesis and characterization of small model complexes, which either mimic structural features of the OEC or are capable of providing insight into the mechanism of O 2 evolution, have become a vital contributor to this scientific field. Our group has contributed to these findings in recent years through synthesis of model complexes, spectroscopic characterization of these systems and probing the reactivity in the context of water oxidation. In this article we describe how models have made significant contributions ranging from understanding the structure of the water-oxidation centre (e.g. contributions to defining a tetrameric Mn 3 Ca-cluster with a dangler Mn) to the ability to discriminate between different mechanistic proposals (e.g. showing that the Babcock scheme for water oxidation is unlikely).

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Efficient Synthesis and Spectroscopic Characterization of Biologically Relevant Pregnane Derivatives, and its Glycoside

Current Chinese Chemistry ◽

10.2174/2666001601999201029204603 ◽

2020 ◽

Vol 01 ◽

Author(s):

Arun Sethi ◽

Ranvijay Pratap Singh ◽

Akriti Bhatia ◽

Priyanka Yadav

Keyword(s):

Spectroscopic Characterization ◽

Spectroscopic Techniques ◽

Efficient Synthesis ◽

Biologically Relevant ◽

Plant Product ◽

Research Article ◽

Naturally Occurring ◽

Dehydropregnenolone Acetate ◽

Pregnane Glycoside

Objective:: In present research article, we synthesized novel pregnane derivatives from 16-dehydropregnenolone acetate (1) which has been obtained by the degradation of naturally occurring plant product-diosgenin. The oxime esters, 3β-acetoxy-pregn-5,16-diene, 20-one O-(2-(6-methoxynaphthalene-2yl) propionyl) oxime (5) and 3β-hydroxy-pregn-5, 16-diene, 20-one O-(2-(4-isobutyl phenyl) propionyl) oxime (6) have been synthesized by reaction of 3β-acetoxy-5,16-pregna-dien-20-oxime (3) with NSAIDs Ibuprofen and naproxen respectively. Methods:: The epoxide derivative 3β-hydroxy-16α, 17α-epoxypregn-5-ene-20-one (4) was opened by BF3.Et2O and yielding product 3,16-di-hydroxy pregn-5-ene-20-one (7) and 3,16,17-tri-hydroxy pregn-5-ene-20-one (8), both the synthesized compounds undergoes esterification with Ibuprofen afforded 3,16-di-(2-(4-isobutyl phenyl) propionoxy) pregn-5-ene-20-one (9) and 3,16-di-(2-(4-isobutyl phenyl) propionoxy) 17-hydroxy pregn-5-ene-20-one (10) respectively. Results and Conclusion:: A one novel pregnane glycoside 3β-[2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosyl]-Oxy-20β-hy-droxy-16α-methoxy-pregn-5-ene (15) has also been synthesized from 3β, 20β-dihydroxy-16α-methoxy-pregn-5-ene (12). After the synthesis all the compounds have been characterized by modern spectroscopic techniques.

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Synthesis and Spectroscopic Characterization of New N4O4 Ligand and Its Transition Metal Ion Complexes with Ni(II), Zn(II) and Cd(II)

Journal of Al-Nahrain University-Science ◽

10.22401/jnus.17.4.04 ◽

2014 ◽

Vol 17 (4) ◽

pp. 27-32

Author(s):

Isam H.T. Al-Karkhi ◽

Keyword(s):

Transition Metal ◽

Metal Ion ◽

Spectroscopic Characterization ◽

Metal Ion Complexes ◽

Transition Metal Ion

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

Journal of the Serbian Chemical Society ◽

10.2298/jsc100414025a ◽

2011 ◽

Vol 76 (2) ◽

pp. 249-261 ◽

Cited By ~ 7

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.

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