Electronic structure modifications induced by increased molecular complexity: from triphenylamine to m-MTDATA

2019 ◽  
Vol 21 (32) ◽  
pp. 17959-17970
Author(s):  
T. Zhang ◽  
I. E. Brumboiu ◽  
V. Lanzilotto ◽  
C. Grazioli ◽  
A. Guarnaccio ◽  
...  

The comprehensive electronic structure of a starburst molecule (m-MTDATA) is thoroughly characterized for the first time, unveiling its good electron donor properties.

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>


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.


2017 ◽  
Vol 31 (02) ◽  
pp. 1650263
Author(s):  
J. G. Yan ◽  
Z. J. Chen ◽  
G. B. Xu ◽  
Z. Kuang ◽  
T. H. Chen ◽  
...  

Using first-principles calculation we investigated the structural, electronic and elastic properties of paramagnetic CaFeAs2. Our results indicated that the density of states (DOS) was dominated predominantly by Fe-3[Formula: see text] states at Fermi levels, and stronger hybridization exists between As1 and As1 atoms. Three hole pockets are formed at [Formula: see text] and Z points, and two electronic pockets are formed at A and E points. The Dirac cone-like bands appear near B and D points. For the first time we calculated the elastic properties and found that CaFeAs2 is a mechanically stable and moderately hard material, it has elastic anisotropy and brittleness, which agrees well with the bonding picture and the calculation of Debye temperature ([Formula: see text]).


ChemInform ◽  
1989 ◽  
Vol 20 (45) ◽  
Author(s):  
D. J. SANDMAN ◽  
G. P. CEASAR ◽  
A. P. III FISHER ◽  
E. SCHRAMM ◽  
D. D. TITUS ◽  
...  

Author(s):  
Zachary Jordan ◽  
Shahriar N. Khan ◽  
Benjamin A. Jackson ◽  
Evangelos Miliordos

Abstract Density functional theory and ab initio multi-reference calculations are performed to examine the stability and electronic structure of boron complexes that host diffuse electrons in their periphery. Such complexes (solvated electron precursors or SEPs) have been experimentally identified and studied theoretically for several s- and d-block metals. For the first time, we demonstrate that a p-block metalloid element can form a stable SEP when appropriate ligands are chosen. We show that three ammonia and one methyl ligands can displace two of the three boron valence electrons to a peripheral 1s-type orbital. The shell model for these outer electrons is identical to previous SEP systems (1s, 1p, 1d, 2s). Further, we preformed the first examination of a molecular system consisting of two SEPs bridged by a hydrocarbon chain. The electronic structure of these dimers is very similar to that of traditional diatomic molecules forming bonding and anti-bonding σ and π orbitals. Their ground state electronic structure resembles that of two He atoms, and our results indicate that the excitation energies are nearly independent of the chain length for four carbon atoms or longer. These findings pave the way for the development of novel materials similar to expanded metals and electrides.


2018 ◽  
Vol 42 (8) ◽  
pp. 5955-5966 ◽  
Author(s):  
Huize Zhang ◽  
Wenqian Li ◽  
Xi Yan ◽  
Wanlin Cai ◽  
Ming Li ◽  
...  

Iridium(iii) complexes that use o-carborane as a chelating ligand have been theoretically investigated for the first time. The superior properties of complexes will potentially promote the discovery of efficient blue-emitting complexes.


2020 ◽  
Vol 49 (7) ◽  
pp. 2273-2279 ◽  
Author(s):  
Dean Hobbis ◽  
Wencong Shi ◽  
Adrian Popescu ◽  
Kaya Wei ◽  
Ryan E. Baumbach ◽  
...  

The synthesis, electronic structure and temperature dependent transport properties of polycrystalline Cu1+xMn2−xInTe4 (x = 0, 0.2, 0.3) are reported for the first time.


2015 ◽  
Vol 44 (7) ◽  
pp. 3128-3135 ◽  
Author(s):  
Jia-Bi Ma ◽  
Jing-Heng Meng ◽  
Sheng-Gui He

The reactivity of the peroxide unit with hydrocarbon molecules on transition metal oxide clusters with a closed-shell electronic structure has been identified for the first time.


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