scholarly journals Nickel(II) Salicylaldiminates: Re-Visiting a Classic

2021 ◽  
Author(s):  
Supaporn Saechio ◽  
Rodolphe CLERAC ◽  
Keith Murray ◽  
Wasinee Phonsri ◽  
Eliseo Ruiz ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Metal Ions ◽  
Coupling Constants ◽  
Ferromagnetic Coupling ◽  
Magnetic Studies ◽  
X Ray ◽  
Substituent Group ◽  
Trinuclear Complexes ◽  
A Minor

A series of Ni(II) trinuclear complexes, [Ni<sub>3</sub>(sala-X)<sub>6</sub>] (sala-X = <i>o</i>-[(<i>p</i>-X-phenylimino)methyl]phenol; X = Br <b>1-Br</b>, Me <b>1-Me</b> and OMe <b>1-OMe</b>), have been prepared and fully characterised. X-ray crystallographic studies reveal that the complexes are composed of <a>three face-sharing octahedral Ni(II) metal ions bridged by the phenoxide oxygens of the sala-X ligands</a>. Magnetic studies indicate that the magnetic Ni(II) centres are ferromagnetically coupled with the substituent group having only a minor impact on the magnitude of coupling. DFT calculations also support ferromagnetic coupling with smaller Ni-O-Ni angles leading to slightly larger coupling constants in line with previous studies.

scholarly journals Nickel(II) Salicylaldiminates: Re-Visiting a Classic

2021 ◽  
Author(s):  
Supaporn Saechio ◽  
Rodolphe CLERAC ◽  
Keith Murray ◽  
Wasinee Phonsri ◽  
Eliseo Ruiz ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Metal Ions ◽  
Coupling Constants ◽  
Ferromagnetic Coupling ◽  
Magnetic Studies ◽  
X Ray ◽  
Substituent Group ◽  
Trinuclear Complexes ◽  
A Minor

A series of Ni(II) trinuclear complexes, [Ni<sub>3</sub>(sala-X)<sub>6</sub>] (sala-X = <i>o</i>-[(<i>p</i>-X-phenylimino)methyl]phenol; X = Br <b>1-Br</b>, Me <b>1-Me</b> and OMe <b>1-OMe</b>), have been prepared and fully characterised. X-ray crystallographic studies reveal that the complexes are composed of <a>three face-sharing octahedral Ni(II) metal ions bridged by the phenoxide oxygens of the sala-X ligands</a>. Magnetic studies indicate that the magnetic Ni(II) centres are ferromagnetically coupled with the substituent group having only a minor impact on the magnitude of coupling. DFT calculations also support ferromagnetic coupling with smaller Ni-O-Ni angles leading to slightly larger coupling constants in line with previous studies.

scholarly journals Molecular cleft or tweezer compounds derived from trioxabicyclo[3.3.1]nonadiene diisocyanate and diacid dichloride

2015 ◽  
Vol 11 ◽  
pp. 1-8 ◽  
Author(s):  
Gert Kollenz ◽  
Ralf Smounig ◽  
Ferdinand Belaj ◽  
David Kvaskoff ◽  
Curt Wentrup
Keyword(s):  
Rare Earth ◽  
Crown Ether ◽  
Dft Calculations ◽  
Metal Ions ◽  
Rare Earth Metal ◽  
Alkaline Earth ◽  
Earth Metal ◽  
X Ray ◽  
X Ray Crystallography ◽  
Derivatives Of

The structures of two derivatives of the bisdioxine diisocyanate 1, the bisurea 4 and the biscarbamate 5, are established by X-ray crystallography and DFT calculations. These compounds possess endo,endo structures, in the case of the bisurea 4 with two nearly parallel pendant chains. The X-ray structures are reproduced very well by DFT calculations. Similar endo,endo conformations are calculated for the bisamide crown ether derivatives 7, where two proximate and nearly parallel crown ether units endow the molecules with a claw-like molecular cleft or tweezer structure as evidenced by an enhanced ability to extract some alkali, alkaline earth and rare earth metal ions.

Synthesis, X-ray characterization, DFT calculations and Hirshfeld surface analysis of thiosemicarbazone complexes of Mn+ ions (n = 2, 3; M = Ni, Cd, Mn, Co and Cu)

CrystEngComm ◽  
2016 ◽  
Vol 18 (6) ◽  
pp. 1009-1023 ◽  
Author(s):  
Ghodrat Mahmoudi ◽  
Alfonso Castiñeiras ◽  
Piotr Garczarek ◽  
Antonio Bauzá ◽  
Arnold L. Rheingold ◽  
...  
Keyword(s):  
Transition Metal ◽  
Dft Calculations ◽  
Metal Ions ◽  
Surface Analysis ◽  
Transition Metal Ions ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
X Ray ◽  
Thiosemicarbazone Complexes

Herein we report the synthesis, X-ray characterization, DFT calculations and Hirshfeld surface analysis of seven complexes of transition metal ions with pyridine-based thiosemicarbazone ligands.

Three 3d–4f Tetranuclear Complexes Based on 2,3,5-Trichlorobenzoic Acid: Syntheses, Structures, and Magnetic Properties

2016 ◽  
Vol 69 (4) ◽  
pp. 446 ◽  
Author(s):  
Yu Zhang ◽  
Ji-Min Zheng
Keyword(s):  
Magnetic Properties ◽  
Infrared Spectroscopy ◽  
Hydrogen Bonds ◽  
Metal Ions ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Triclinic Space Group ◽  
X Ray ◽  
Ferromagnetic Interactions ◽  
Tetranuclear Complexes

The solvothermal reactions of 2,3,5-trichlorobenzoic acid (HL) 2,2′-bipyridine (bipy), CoCl2·6H2O, and Ln2O3 afforded three novel 3d–4f tetranuclear complexes Co2Ln2(L)10(bipy)2 (Ln = Dy 1, Ho 2, and Er 3), which have been characterized by single-crystal X-ray diffraction, infrared spectroscopy, and element analyses. Complexes 1–3 crystallize in the triclinic space group P1, and the completely deprotonated L ligands possess μ2 : η2, η1 and μ2 : η1, η1 coordination modes to bridge adjacent metal ions, which further connect into 2D layers by hydrogen bonds. Magnetic studies indicate ferromagnetic interactions between adjacent metal ions in complexes 1 and 3.

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

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.

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

The Concerted Nature of the Enzymatic Cyclization of Rings A-D of Squalene to Hopene

2008 ◽  
Vol 73 (6-7) ◽  
pp. 786-794 ◽  
Author(s):  
B. Andes Hess ◽  
Lidia Smentek
Keyword(s):  
Dft Calculations ◽  
Conformational Analysis ◽  
X Ray

A conformational analysis of squalene encapsulated in squalene-hopene cyclase has been performed based on Schulz's X-ray structure and our DFT calculations. Based on this analysis it is concluded that the formation of rings A-D in the cyclization of squalene are likely to be a concerted but highly asynchronous reaction.

scholarly journals X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84 ◽  
Author(s):  
Satoru Urakawa ◽  
Toru Inoue ◽  
Takanori Hattori ◽  
Asami Sano-Furukawa ◽  
Shinji Kohara ◽  
...  
Keyword(s):  
Oxide Glasses ◽  
Void Space ◽  
X Ray Diffraction ◽  
Amorphous Sio2 ◽  
Sio2 Glass ◽  
X Ray ◽  
X Ray Scattering ◽  
Medium Range ◽  
Two Phases ◽  
A Minor

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 Å. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si–OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra.

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