scholarly journals Synthesis, Photophysical, and Computational Studies of a Bridged IrΙΙΙ-PtΙΙ Heterodimetallic Complex

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 236
Author(s):  
Si-Hai Wu ◽  
Dian-Xue Ma ◽  
Zhong-Liang Gong ◽  
Junjie Ma ◽  
Jiang-Yang Shao ◽  
...  
Keyword(s):  
Excited State ◽  
Electronic Structures ◽  
Theoretical Calculations ◽  
Excitation Wavelength ◽  
Computational Studies ◽  
Ambient Conditions ◽  
Excited State Lifetime ◽  
X Ray ◽  
Experimental Findings ◽  
Single Emission

An IrIII-PtII heterodimetallic complex [(ppy)2Ir(dapz)PtCl2]Cl (4), together with the corresponding monometallic complexes [(dapz)PtCl2] (2) and [(ppy)2Ir(dapz)]Cl (3) was designed and prepared, where dapz is 2,5-di(N-methyl-N′-(pyrid-2-yl)amino)pyrazine and ppy is 2-phenylpyridine, respectively. Single-crystal X-ray analysis was carried out for complex 4, displaying the intermolecular Pt∙∙∙Pt and aromatic plane∙∙∙plane distances of 3.839 and 3.886 Å, respectively. The monometallic complex 2 exhibits a single emission maximum at 432 nm with a shorter excited-state lifetime (τ) of 6 ns, while complex 3 exhibits an emission band at 454 nm with a longer excited-state lifetime of 135 ns in CH3CN (N2-saturated) under ambient conditions. In contrast, the heterodimetallic complex 4 displays intriguing excitation wavelength-dependent dual singlet and triplet emissions. Theoretical calculations of the electronic structures and absorption spectra of these complexes were carried out to assist the interpretation of these experimental findings.

scholarly journals Anti-Kasha Behavior of 3-Hydroxyflavone and Its Derivatives

2021 ◽  
Vol 22 (20) ◽  
pp. 11103
Author(s):  
Ka Wa Fan ◽  
Hoi Ling Luk ◽  
David Lee Phillips
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Transient Absorption ◽  
Intramolecular Proton Transfer ◽  
Transient Absorption Spectroscopy ◽  
Excitation Wavelength ◽  
Computational Studies ◽  
Femtosecond Transient Absorption ◽  
First Excited State ◽  
Experimental Findings

Excited state intramolecular proton transfer (ESIPT) in 3-hydroxyflavone (3HF) has been known for its dependence on excitation wavelength. Such a behavior violates Kasha’s rule, which states that the emission and photochemistry of a compound would only take place from its lowest excited state. The photochemistry of 3HF was studied using femtosecond transient absorption spectroscopy at a shorter wavelength excitation (266 nm), and these new experimental findings were interpreted with the aid of computational studies. These new results were compared with those from previous studies that were obtained with a longer wavelength excitation and show that there exists a pathway of proton transfer that bypasses the normal first excited state from the higher excited state to the tautomer from first excited state. The experimental data correlate with the electron density difference calculations such that the proton transfer process is faster on the longer excitation wavelength than compared to the shorter excitation wavelength.

Society Photoemission and Photoabsorption Study of YNi2−xCoxB2C Superconductors

2001 ◽  
Vol 678 ◽  
Author(s):  
L.-S. Hsu ◽  
G. Y. Guo ◽  
C.-J. Chen ◽  
M.-D. Lan ◽  
J.-F. Lee
Keyword(s):  
Fine Structure ◽  
Electronic Structures ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Photoemission Spectrum ◽  
Partial Density ◽  
Superconducting Transition ◽  
X Ray ◽  
X Ray Absorption ◽  
Exafs Spectra

AbstractThe electronic structures of five polycrystalline YNi2−xCoxB2C (x=0, 0.05, 0.1, 0.15, and 0.2) borocarbide superconductors were studied by photoemission and photoabsorption spectroscopies and theoretical calculations. The valence-band (VB) photoemission spectrum is compared with the theoretical total and partial density-of-states (DOS) curves. The VB satellite is peaked at a binding energy (EB) of 6 eV. The Ni K-edge x-ray absorption near edge spectra (XANES) are compared with the calculated XANES spectra for these intermetallic compounds. Extended x-ray absorption fine structure (EXAFS) spectra at the Ni and Co K edges are analyzed to yield the structural parameters. The decrease of the superconducting transition temperatures (Tc) with addition of Co dopant in these compounds is due to a decrease of the total DOS at the Fermi level (EF).

Crystallographic and computational studies of a new organoarsenate compound: o-anisidinium dihydroarsenate

2019 ◽  
Vol 75 (2) ◽  
pp. 128-134
Author(s):  
Ali Harchani ◽  
Damian Trzybiński ◽  
Sylwia Pawlędzio ◽  
Krzysztof Woźniak ◽  
Amor Haddad
Keyword(s):  
Crystal Structure ◽  
Solution Method ◽  
Theoretical Calculations ◽  
Hirshfeld Surface ◽  
Computational Studies ◽  
Supramolecular Architecture ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Electrophilic Reactivity

The crystal structure and the results of theoretical calculations for the new organoarsenate salt o-anisidinium dihydroarsenate (systematic name: 2-methoxyanilinium dihydrogen arsenate), C7H10NO+·H2AsO4 −, are reported. The salt, crystallizing in the triclinic space group P\overline{1}, was synthesized using a solution method and was characterized by single-crystal X-ray diffraction analysis. It possesses a layered supramolecular architecture in the crystal. The intermolecular interactions were studied using Hirshfeld surface analysis which confirmed that hydrogen bonds and H...H contacts play dominant roles in the crystal structure of the investigated system. An analysis of the electronic structure and molecular modelling using charge distribution confirms the good electrophilic reactivity of the title compound.

Synthesis and characterization of nitrides of iridium and palladium

2008 ◽  
Vol 23 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Jonathan C. Crowhurst ◽  
Alexander F. Goncharov ◽  
B. Sadigh ◽  
J.M. Zaug ◽  
D. Aberg ◽  
...  
Keyword(s):  
First Principles ◽  
Diamond Anvil Cell ◽  
Theoretical Calculations ◽  
X Ray ◽  
In Situ Techniques ◽  
Diamond Anvil ◽  
Experimental Findings ◽  
Laser Heated

We describe the synthesis of nitrides of iridium and palladium using the laser-heated diamond anvil cell. We have used the in situ techniques of x-ray powder diffraction and Raman scattering to characterize these compounds and have compared our experimental findings where possible to the results of first-principles theoretical calculations. We suggest that palladium nitride is isostructural with pyrite, while iridium nitride has a monoclinic symmetry and is isostructural with baddeleyite.

scholarly journals Synthesis, structural characterization and biological activity of new pyrazolo[4,3-e][1,2,4]triazine acyclonucleosides

2019 ◽  
Author(s):  
Mariusz Mojzych ◽  
Zbigniew Karczmarzyk ◽  
Joanna Matysiak ◽  
Andrzej Fruziński
Keyword(s):  
Electronic Structures ◽  
Model Compound ◽  
Human Cancer ◽  
Theoretical Calculations ◽  
Molecular Structures ◽  
X Ray ◽  
Human Cancer Cell Lines ◽  
Docking Method ◽  
Mcf 7 ◽  
Molecular Docking Method

A series of new pyrazolo[4,3-e][1,2,4]triazine acyclonucleosides 2-5 and 8 were prepared and evaluated for their anticancer activity against human cancer cell lines (MCF-7, K-562) and CDK2/E as well as Abl protein kinases inhibitors. Lipophilicity of the compounds was determined using C-18 and IAM chromatography. In order to confirm molecular structures and synthesis pathway of new acyclonucleosides X-ray analysis was performed for model compound 3. Theoretical calculations at DFT/B3LYP/6-311++G(d,p) level were used for characterization electronic structures of 1–8. The potential antiviral activity of acyclonucleoside 2–8 was tested in silico using molecular docking method.

scholarly journals Crystal Structure, Spectroscopy, SEM Analysis, and Computational Studies of N-(1,3-Dioxoisoindolin-2yl)benzamide

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Hakan Bülbül ◽  
Yavuz Köysal ◽  
Necmi Dege ◽  
Sümeyye Gümüş ◽  
Erbil Ağar
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Theoretical Calculations ◽  
Sem Analysis ◽  
Monoclinic Space Group ◽  
Computational Studies ◽  
X Ray Diffraction ◽  
Ethanolic Solution ◽  
X Ray

The compound N-(1,3-dioxoisoindolin-2yl)benzamide, C15H10N2O3, was prepared by the heating of an ethanolic solution of 2-hydroxy-1H-isoindole-1,3(2H)-dione and 4-chloroaniline. The product was characterised using a combination of IR spectroscopy, SEM, and single crystal X-ray diffraction techniques. In addition to the experimental analysis, theoretical calculations were used to investigate the crystal structure in order to compare experimental and theoretical values. The X-ray diffraction analysis shows that the compound crystallises in the monoclinic space group P21/c with the geometric parameters of a=13.5324(11) Å, b=9.8982(8) Å, c=9.7080(8) Å, and β=95.425(6)°. The crystal structure is held together by a network of N-H⋯O hydrogen bonds involving the carboxamide group.

scholarly journals Electronic structures of cyclometalated palladium complexes in the higher oxidation states

2015 ◽  
Vol 44 (37) ◽  
pp. 16586-16591 ◽  
Author(s):  
Bao N. Nguyen ◽  
Luis A. Adrio ◽  
Tim Albrecht ◽  
Andrew J. P. White ◽  
Mark A. Newton ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Electronic Structures ◽  
Theoretical Calculations ◽  
Palladium Complexes ◽  
Oxidation States ◽  
X Ray ◽  
X Ray Crystallography

Electronic structures of Pd(ii), Pd(iii) and Pd(iv) complexes were examined using X-ray crystallography and absorption spectroscopy, supplemented by theoretical calculations.

scholarly journals Discovery of New Metallic and Superconducting Phase in GaTa4Se8 Under High Pressure

2020 ◽  
Author(s):  
Hongshan Deng ◽  
Jianbo Zhang ◽  
Min Yong Jeong ◽  
Raimundas Sereika ◽  
Dong Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Theoretical Calculations ◽  
Mott Insulator ◽  
Metallic Phase ◽  
Superconducting Phase ◽  
Ambient Conditions ◽  
Quantum Phases ◽  
X Ray ◽  
Magnetic Metal ◽  
Pressure Regime

Abstract Pressure is a unique thermodynamic variable to explore the phase competitions and novel phases inaccessible at ambient conditions. The resistive switching material GaTa4Se8 displays several quantum phases under pressure, such as Jeff = 3/2 Mott insulator, correlated quantum magnetic metal, and d-wave topological superconductivity, which has recently drawn mounting interest. Using high-pressure Raman, X-ray diffraction, extended X-ray absorption, and transport measurements, together with theoretical calculations, we reveal a remarkably rich phase diagram of this molecular magnetic Mott insulator at pressures up to ~ 68 GPa. In this previously unreached pressure regime, we find, GaTa4Se8 exhibits a new metallic phase whose structural and magnetic properties are clearly distinctive from the lower pressure one. Further, we identify a new superconducting phase in this high-pressure regime below Tc ~ 5.5K. Our discoveries highlight GaTa4Se8 as a unique playground in which novel quantum phases and orders coexist and compete with each other; ranges from Mott insulator to Fermi liquid and exhibits multiple metallic and superconducting states.

Synthesis and Characterization of Nitrides of Iridium and Palladium

2006 ◽  
Vol 987 ◽  
Author(s):  
Jonathan Crowhurst ◽  
Alexander Goncharov ◽  
Babak Sadigh ◽  
Joseph Zaug ◽  
Yue Meng ◽  
...  
Keyword(s):  
First Principles ◽  
Diamond Anvil Cell ◽  
Theoretical Calculations ◽  
X Ray ◽  
In Situ Techniques ◽  
Diamond Anvil ◽  
Experimental Findings ◽  
Laser Heated

AbstractWe describe the synthesis of nitrides of iridium and palladium using the laser-heated diamond anvil cell. We have used the in-situ techniques of x-ray powder diffraction and Raman scattering to characterize these compounds and have compared our experimental findings where possible to the results of first-principles theoretical calculations. We suggest that palladium nitride is isostructural with pyrite while iridium nitride has a monoclinic symmetry and may be isostructural with baddeleyite.

Sign in / Sign up

Export Citation Format

Share Document