scholarly journals Synthesis and spectroscopic study of transition metal complexes of tridentate ligand formed by direct condensation of o-vanillin and 2-aminophenol: X-ray structural characterization of the zinc(II) complex

2018 ◽  
Vol 9 (4) ◽  
pp. 281-286
Author(s):  
Amadou Gueye ◽  
Farba Bouyagui Tamboura ◽  
Jean-Marc Planeix ◽  
Nathalie Gruber ◽  
Mohamed Gaye

The reactions of the Schiff base 2-((2-hydroxyphenylimino)methyl)-6-methoxyphenol (H2L), obtained by direct condensation of 2-aminophenol and 2-hydroxy-3-methoxybenzaldehyde, with some transition  metal ions (Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)) afforded complexes of general formulae [M2(L)2(solvent)x] (M: Mn, Co, Ni, Cu or Zn; Solvent: DMSO or H2O). These compounds were characterized by elemental analysis, UV-Vis, IR, 1H- and 13C-NMR spectroscopies, molar conductivity and room temperature magnetic measurements. The structure of zinc(II) complex has been determined by X-ray crystallography. Crystal data for C32H34N2O8S2Zn2 (M =769.47 g/mol): Orthorhombic, space group Pbca (no. 61), a = 16.3176(7) Å, b = 9.1247(3) Å, c = 21.8274(10) Å, V = 3250.0(2) Å3, Z = 4, T = 173(2) K, μ(MoKα) = 1.658 mm-1, Dcalc = 1.573 g/cm3, 28116 reflections measured (4.5° ≤ 2Θ ≤ 60.3°), 4457 unique (Rint = 0.0409, Rsigma = 0.0371) which were used in all calculations. The final R1 was 0.0307(0.0466) and wR2 was 0.0649 (0.0701) (all data). The coordination sphere of the Zn center is best described as a trigonal bipyramid.

2019 ◽  
Author(s):  
Christopher Jones ◽  
Matthew Asay ◽  
Lee Joon Kim ◽  
Jack Kleinsasser ◽  
Ambarneil Saha ◽  
...  

Here we apply microcrystal electron diffraction (MicroED) to the structural determination of transition metal complexes. We find that the simultaneous use of 300 keV electrons, very low electron doses, and an ultra-sensitive camera allows for the collection of data without cryogenic cooling of the stage. This technique reveals the first crystal structures of the classic zirconocene hydride, colloquially known as “Schwartz’s reagent”, a novel Pd(II) complex not amenable to solution-state NMR or X-ray crystallography, and five other paramagnetic or diamagnetic transition metal complexes.


2014 ◽  
Vol 69 (6) ◽  
pp. 737-741 ◽  
Author(s):  
Gustavo A. Echeverría ◽  
Oscar E. Piro ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

Ammonium acesulfamate, (NH4)C4H4NO4S, was prepared by the reaction of acesulfamic acid and ammonium carbonate in aqueous solution, and characterized by elemental analysis and 1H and 13C NMR spectroscopy. Its crystal and molecular structure was determined by single-crystal X-ray diffraction methods. The substance crystallizes in the orthorhombic space group Pnma with Z = 4 molecules per unit cell. The NH4+ ion generates medium to strong hydrogen bonds with the carbonylic oxygen, the iminic nitrogen and the sulfonyl oxygen atoms of the acesulfamate anion. The FTIR spectrum of the compound was also recorded and is briefly discussed.


2002 ◽  
Vol 756 ◽  
Author(s):  
J. Katana Ngala ◽  
Natasha A. Chernova ◽  
Luis Matienzo ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham

ABSTRACTThe layered compounds of formula LiNi0.4Mn0.6-yCoyO2, for y=0.2, 0.3, and 0.4 and LiNi0.7-yMn0.3CoyO2 for y=0.3, and 0.1 were synthesized at 800°C. X-ray powder diffraction indicates layered structure of R 3m symmetry similar to a-NaFeO2. Rietveld refinement data shows that Mn and Ni increase the tendency of transition metal ions to migrate into the interlayer sites relative to LiCoO2. Both magnetic susceptibility and XPS data support a 2+ oxidation state for Ni and 4+ and 3+ for Mn and Co, respectively. The layered compound LiNi0.4Mn0.4Co0.2O2 shows a high initial capacity of about 200mAh/g when cycled between 2.5V and 4.3 V at 20°C.


1991 ◽  
Vol 44 (2) ◽  
pp. 303 ◽  
Author(s):  
R Bhula ◽  
DC Weatherburn

The crystal structure of [ Mn ( terpy )2](I3)2( terpy = 2,2°:6°,2°-terpyridene) has been determined by X-ray crystallography. The crystals are triclinic, space group Pī , a 9.357(4), b 8.600(2), c 24.531(8) Ǻ, α 93.64(2), B 95.58(3), γ 91.52(2)°, Z 2, V 1960(1)Ǻ3. The structure has been refined to a residual R of 0.065 (Rw 0.070). The coordination sphere of the metal ion is distorted octahedral with each terpy ligand coordinated in a meridional fashion. The structure is compared with those of other M( terpy )2n+ complexes formed by first-row transition metal ions.


2019 ◽  
Author(s):  
Christopher Jones ◽  
Matthew Asay ◽  
Lee Joon Kim ◽  
Jack Kleinsasser ◽  
Ambarneil Saha ◽  
...  

Here we apply microcrystal electron diffraction (MicroED) to the structural determination of transition metal complexes. We find that the simultaneous use of 300 keV electrons, very low electron doses, and an ultra-sensitive camera allows for the collection of data without cryogenic cooling of the stage. This technique reveals the first crystal structures of the classic zirconocene hydride, colloquially known as “Schwartz’s reagent”, a novel Pd(II) complex not amenable to solution-state NMR or X-ray crystallography, and five other paramagnetic or diamagnetic transition metal complexes.


1978 ◽  
Vol 56 (16) ◽  
pp. 2099-2108 ◽  
Author(s):  
Kenneth R. Breakell ◽  
Steven J. Rettig ◽  
Douglas L. Singbeil ◽  
Alan Storr ◽  
James Trotter

The anionic tridentate ligand, [MeGa(N2C3H3)3]−, has been characterized and its coordinating properties studied. It acts as a six-electron chelating ligand to divalent transition metal ions giving complexes of the type, [MeGa(N2C3H3)3]2M (M = Mn, Fe, Co, Ni, Cu, Zn), believed to possess an octahedral MN6 core. The ligand also forms numerous carbonyl complexes and its coordinating ability in Mo, W, and Mn carbonyl derivatives is compared with that of similar boron ligands and the η5-C5H5 ligand. From ir measurements and bond length data it appears that the [MeGa(N2C3H3)3]− ligand is superior in creating an electron-rich transition metal centre, and it also affords greater steric protection for the central metal. The expected tridentate chelating nature of the new ligand has been demonstrated through a crystal structure determination of the complex [MeGa(N2C3H3)3]Mo(CO)2(η3-C3H5). Crystals of this complex are tetragonal, a = 26.217(3), c = 10.723(2) Å, Z = 16, space group I41/a. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to a final R of 0.030 and Rw of 0.031 for 2582 reflections with I ≥ 3σ(I).


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7347
Author(s):  
Rosita Diana ◽  
Ugo Caruso ◽  
Francesco Silvio Gentile ◽  
Luigi Di Costanzo ◽  
Barbara Panunzi

In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a “turn-on” of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis.


2019 ◽  
Author(s):  
Christopher Jones ◽  
Matthew Asay ◽  
Lee Joon Kim ◽  
Jack Kleinsasser ◽  
Ambarneil Saha ◽  
...  

Here we apply microcrystal electron diffraction (MicroED) to the structural determination of transition metal complexes. We find that the simultaneous use of 300 keV electrons, very low electron doses, and an ultra-sensitive camera allows for the collection of data without cryogenic cooling of the stage. This technique reveals the first crystal structures of the classic zirconocene hydride, colloquially known as “Schwartz’s reagent”, a novel Pd(II) complex not amenable to solution-state NMR or X-ray crystallography, and five other paramagnetic or diamagnetic transition metal complexes.


1987 ◽  
Vol 65 (11) ◽  
pp. 2618-2623 ◽  
Author(s):  
Frank E. Hruska ◽  
Rudy Sebastian ◽  
André Grand ◽  
Lucienne Voituriez ◽  
Jean Cadet

X-ray crystallography was used to determine the structure of (−)cis(5R,6S)-5,6-dihydroxy-5,6-dihydrothymidine, a γ-radiation induced product of thymidine. The crystals belong to the orthorhombic space group P212121 and have cell dimensions a = 8.420(1) Å, b = 10.422(1) Å, and 13.552(1) Å. The half-chair pucker of the 5,6-saturated pyrimidine ring is similar to that observed for the isolated base with the cis configuration, and is described by the Cremer–Pople parameters Q = 0.48 Å, θ = 62°, and [Formula: see text]. The conformation about the N-glycosyl bond is anti; the χ angle (−111.6(5)°) lies at one extreme of the range previously seen for nucleosides (−180 to −115°). The pucker 2T1 of the sugar (P = 151.2°; τm = 36.5°) contrasts with the O4′-endo type of pucker seen in 5,6-dihydrothymidine (0T4) and (5S)-5-hydroxy-5,6-dihydrothymidine (0T1). The conformation about the C4′—C5′ bond is gauche+. The solid state structure is similar to that determined in aqueous solution by 1H nmr.


2019 ◽  
Vol 43 (38) ◽  
pp. 15072-15086
Author(s):  
Pavel A. Panchenko ◽  
Anastasia D. Zubenko ◽  
Ekaterina Y. Chernikova ◽  
Yuri V. Fedorov ◽  
Anna V. Pashanova ◽  
...  

Complex formation of benzodiazacrown ethers with heavy and transition metal ions was studied using NMR spectroscopy, potentiometry and X-ray crystallography.


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