scholarly journals From half-metallic to magnetic semiconducting triazine g-C4N3: computational designs and insight

RSC Advances ◽  
2021 ◽  
Vol 11 (62) ◽  
pp. 38944-38948
Author(s):  
Pham Nam Phong ◽  
Nguyen Thi Ngoc ◽  
Pham Thanh Lam ◽  
Manh-Thuong Nguyen ◽  
Huy-Viet Nguyen

A simple picture of charge transfer has been given, for the first time, as physicochemical insight into the electronic structure routes from half-metallic to magnetic semiconducting triazine g-C4N3.

2021 ◽  
Author(s):  
Fabrizio Ortu ◽  
simon Randall ◽  
David J. Moulding ◽  
Adam woodward ◽  
Karsten Meyer ◽  
...  

We report the synthesis and characterization of a new family of pentavalent uranyl amide complexes, supported also by photoluminescence and theoretical investigations. These studies reveal for the first time that the UV-visible emission of uranyl(V) is an admixture of charge transfer transitions accompanied by vibronic coupling of the quartet excited state with uranyl oxo and amide vibrations, thereby offering new insights into the electronic structure of the reactive uranyl(V)


2021 ◽  
Author(s):  
Fabrizio Ortu ◽  
simon Randall ◽  
David J. Moulding ◽  
Adam woodward ◽  
Karsten Meyer ◽  
...  

We report the synthesis and characterization of a new family of pentavalent uranyl amide complexes, supported also by photoluminescence and theoretical investigations. These studies reveal for the first time that the UV-visible emission of uranyl(V) is an admixture of charge transfer transitions accompanied by vibronic coupling of the quartet excited state with uranyl oxo and amide vibrations, thereby offering new insights into the electronic structure of the reactive uranyl(V)


1994 ◽  
Vol 349 ◽  
Author(s):  
Keivan Esfarjani ◽  
Bing-Lin Gu ◽  
Yutaka Maruyama ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe

ABSTRACTRecent studies of electronic structure of solid fullerenes have revealed many interesting properties of these systems. In the present paper, the effects of substitution of carbon atoms by nitrogen and/or boron. We have modified our C60 fcc band-structure program to calculate the electronic properties of the C58BN fcc crystal, where we adopt the mixed-basis approach in which the Is, 2s, and 2p orbitals in addition to about 2000 plane waves are included. The band structure and the charge density distribution are calculated for the first time. When B and N are substituted in places of two C atoms sharing a double bond in C60, we found that there is no donor nor accepter level, and no net charge transfer between B and N. This character is considerably different from the boron-substituted fullerenes.


2021 ◽  
Author(s):  
Fabrizio Ortu ◽  
simon Randall ◽  
David J. Moulding ◽  
Adam woodward ◽  
Karsten Meyer ◽  
...  

We report the synthesis and characterization of a new family of pentavalent uranyl amide complexes, supported also by photoluminescence and theoretical investigations. These studies reveal for the first time that the UV-visible emission of uranyl(V) is an admixture of charge transfer transitions accompanied by vibronic coupling of the quartet excited state with uranyl oxo and amide vibrations, thereby offering new insights into the electronic structure of the reactive uranyl(V)


2008 ◽  
Vol 61 (12) ◽  
pp. 981 ◽  
Author(s):  
Igor Novak ◽  
Branka Kovač

The HeI/HeII photoelectron spectra of substituted fluorenes (2-aminofluorene, 2,7-dibromofluorene, 2-acetylfluorene, and 9-trimethylsilylfluorene) are reported for the first time. We have observed significant changes in the π-electronic structure of the title molecules on substitution at 2-, 7-, and 9-positions and interpreted them within the theoretical framework of resonance and inductive effects. The substituents attached to fluorene at these positions govern the photophysical behaviour and properties of polymetallaynes that contain the fluorene moiety. The mediated properties include the size of the polymer bandgap, various non-linear optical properties, and the intensity and lifetime of luminescence processes. Our spectral results provide some detailed explanations of substituent influences in the form of, for example, orbital ionization energies, which can be further related to charge-transfer processes present in these metallo-organic polymers.


Author(s):  
Yimei Zhu ◽  
J. Tafto

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.


2019 ◽  
Author(s):  
Victor Y. Suzuki ◽  
Luís Henrique Cardozo Amorin ◽  
Natália H. de Paula ◽  
Anderson R. Albuquerque ◽  
Julio Ricardo Sambrano ◽  
...  

<p>We report, for the first time, new insights into the nature of the band gap of <a>CuGeO<sub>3</sub> </a>(CGO) nanocrystals synthesized from a microwave-assisted hydrothermal method in the presence of citrate. To the best of our knowledge, this synthetic approach has the shortest reaction time and it works at the lowest temperatures reported in the literature for the preparation of these materials. The influence of the surfactant on the structural, electronic, optical, and photocatalytic properties of CGO nanocrystals is discussed by a combination of experimental and theoretical approaches, and that results elucidates the nature of the band gap of synthetized CGO nanocrystals. We believe that this particular strategy is one of the most critical parameters for the development of innovative applications and that result could shed some light on the emerging material design with entirely new properties.</p> <p><b> </b></p>


2020 ◽  
pp. 128-138
Author(s):  
A. S. Bik-Bulatov

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.


2001 ◽  
Vol 66 (1) ◽  
pp. 139-154 ◽  
Author(s):  
M. Fátima C. Guedes Da Silva ◽  
Luísa M. D. R. S. Martins ◽  
João J. R. Fraústo Da Silva ◽  
Armando J. L. Pombeiro

The organonitrile or carbonyl complexes cis-[ReCl(RCN)(dppe)2] (1) (R = 4-Et2NC6H4 (1a), 4-MeOC6H4 (1b), 4-MeC6H4 (1c), C6H5 (1d), 4-FC6H4 (1e), 4-ClC6H4 (1f), 4-O2NC6H4 (1g), 4-ClC6H4CH2 (1h), t-Bu (1i); dppe = Ph2PCH2CH2PPh2), or cis-[ReCl(CO)(dppe)2] (2), as well as trans-[FeBr(RCN)(depe)2]BF4 (3) (R = 4-MeOC6H4 (3a), 4-MeC6H4 (3b), C6H5 (3c), 4-FC6H4 (3d), 4-O2NC6H4 (3e), Me (3f), Et (3g), 4-MeOC6H4CH2 (3h); depe = Et2PCH2CH2PEt2), novel trans-[FeBr(CO)(depe)2]BF4 (4) and trans-[FeBr2(depe)2] (5) undergo, as revealed by cyclic voltammetry at a Pt-electrode and in aprotic non-aqueous medium, two consecutive reversible or partly reversible one-electron oxidations assigned as ReI → ReII → ReIII or FeII → FeIII → FeIV. The corresponding values of the oxidation potentials IE1/2ox and IIE1/2ox (waves I and II, respectively) correlate with the Pickett's and Lever's electrochemical ligand and metal site parameters. This allows to estimate these parameters for the various nitrile ligands, depe and binding sites (for the first time for a FeIII/IV couple). The electrochemical ligand parameter show dependence on the "electron-richness" of the metal centre. The values of IE1/2ox for the ReI complexes provide some supporting for a curved overall relationship with the sum of Lever's electrochemical ligand parameter. The Pickett parametrization for closed-shell complexes is extended now also to 17-electron complexes, i.e. with the 15-electron ReII and FeIII centres in cis-{[ReCl(dppe)2]}+ and trans-{FeBr(depe)2}2+, respectively.


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