scholarly journals Synthesis and Structural Characterization of the Tetranuclear Iron(Iii) Cluster with Salicylic Acid

2020 ◽  
Vol 15 (2) ◽  
pp. 62-68
Author(s):  
Viorina Gorinchoy
Keyword(s):  
Salicylic Acid ◽  
Diffraction Analysis ◽  
Structural Characterization ◽  
Spectroscopic Method ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ir Spectroscopic ◽  
Oxygen Atoms

A new tetra-homonuclear iron(III) cluster, [Fe4O2(Sal)4(H2O)6]·4DMA·0.75H2O, where Sal= salicylic acid and DMA= N,N-dimethylacetamide consolidated via two µ3-oxo- and four salicylate-bridges was synthesized and characterized by IR spectroscopic method as well as by single crystal X-ray diffraction analysis. The structure of the obtained tetranuclear compound consists of four FeIII atoms in a “butterfly” arrangement. The coordination sphere of each of the two central FeIII atoms is generated by two μ3-oxo-bridging atoms and four oxygen atoms provided by the tridentate-bridging Sal2- ligands, while the coordination polyhedron of another two iron atoms involve six oxygen atoms from three water molecules, two salicylic and one μ3-oxigen atom. The Fe-O distances within Fe-O-Fe bridge are of 2.102(3) Å (for wing-body) and 2.038(3) Å (for body-body).

The Synthesis and Structural Characterization of Peralkylated Triguanide Superbases

2014 ◽  
Vol 67 (7) ◽  
pp. 1129 ◽  
Author(s):  
Vjekoslav Štrukil ◽  
Edislav Lekšić ◽  
Ernest Meštrović ◽  
Mirjana Eckert-Maksić
Keyword(s):  
Diffraction Analysis ◽  
Gas Phase ◽  
Structural Characterization ◽  
Positive Charge ◽  
Coupling Reaction ◽  
Chloride Salt ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time

Organic superbases derived from a peralkylated triguanide framework have been synthesized in a coupling reaction between monosubstituted guanidines and a Vilsmeier salt. Single crystal X-ray diffraction analysis of the chloride salt allowed the structural characterization of the benzyl derivative for the first time and revealed an effective delocalization of the positive charge despite significant distortion of the triguanide cation planarity. With the calculated gas phase basicity ranging from 262 to 265 kcal mol–1 and pKa values in acetonitrile between 28 and 30, these compounds have been evaluated as potential organocatalysts in the transesterification reaction of vegetable oil.

scholarly journals Structural characterization of self-assembled quantum dot structures by X-ray diffraction techniques

1997 ◽  
Vol 306 (2) ◽  
pp. 198-204 ◽  
Author(s):  
A.A. Darhuber ◽  
J. Stangl ◽  
V. Holy ◽  
G. Bauer ◽  
A. Krost ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Structural Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembled

scholarly journals Synthesis and Complexation Properties of 2-Hydroxy-5-methoxyphenylphosphonic Acid (H3L1). Crystal Structure of the [Cu(H2L1)2(Н2О)2] Complex

2021 ◽  
Vol 91 (11) ◽  
pp. 2176-2186
Author(s):  
G. S. Tsebrikova ◽  
Yu. I. Rogacheva ◽  
I. S. Ivanova ◽  
A. B. Ilyukhin ◽  
V. P. Soloviev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Methoxy Group ◽  
Protonation Constants ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Intramolecular Hydrogen ◽  
Oxygen Atoms

Abstract 2-Hydroxy-5-methoxyphenylphosphonic acid (H3L1) and the complex [Cu(H2L1)2(H2O)2] were synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. The polyhedron of the copper atom is an axially elongated square bipyramid with oxygen atoms of phenolic and of monodeprotonated phosphonic groups at the base and oxygen atoms of water molecules at the vertices. The protonation constants of the H3L1 acid and the stability constants of its Cu2+ complexes in water were determined by potentiometric titration. The protonation constants of the acid in water are significantly influenced by the intramolecular hydrogen bond and the methoxy group. The H3L1 acid forms complexes CuL‒ and CuL24‒ with Cu2+ in water.

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