scholarly journals Basis Set Dependency of Molecular Electronic Structures

1986 ◽  
Vol 59 (9) ◽  
pp. 2729-2733 ◽  
Author(s):  
Hiroshi Ichikawa ◽  
Keiichiro Sameshima ◽  
Yukiko Ebisawa
Keyword(s):  
Electronic Structures ◽  
Basis Set ◽  
Molecular Electronic

Supramolecular structures of N 4-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines

2003 ◽  
Vol 59 (2) ◽  
pp. 263-276 ◽  
Author(s):  
Manuel Melguizo ◽  
Antonio Quesada ◽  
John N. Low ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Electronic Structures ◽  
Supramolecular Structure ◽  
Supramolecular Structures ◽  
Stacking Interactions ◽  
Molecular Electronic ◽  
Π Stacking

The molecular and supramolecular structures of eight N 4-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines are discussed, along with one analogue containing no nitroso substituent. The nitroso derivatives all exhibit polarized molecular-electronic structures leading to extensive charge-assisted hydrogen bonding between the molecules. The intermolecular interactions include hard hydrogen bonds of N—H...O and N—H...N types, together with O—H...O and O—H...N types in the monohydrate of 2-amino-6-benzyloxy-4-piperidino-5-nitrosopyrimidine, soft hydrogen bonds of C—H...O, C—H...π(arene) and N—H...π(arene) types and aromatic π...π stacking interactions. The predominant supramolecular structure types take the form of chains and sheets, but no two of the structures determined here exhibit the same combination of hydrogen-bond types.

scholarly journals Density Functional Calculations on the Molecular, Electronic Structures of Metal-Free, N,N'-Dideuterio and Magnesium Tetra-3,4-Pyridino-Porphyrazines

2019 ◽  
pp. 40-44
Author(s):  
Zhongqiang Liu ◽  
Xianxi Zhang
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Atomic Charge ◽  
Substitution Effect ◽  
Membered Ring ◽  
Basis Set ◽  
Metal Free ◽  
B3lyp Level ◽  
Homo Lumo ◽  
Optimized Geometries

A theoretical calculation of the fully optimized geometries and electronic structures of the metal-free Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2*), N,N-Dideuterio (TPdPzD2*), and Magnesium (TPdPzMg*) tetra-3,4-pyridino-porphyrazine has been conducted with the density functional B3LYP level using the 6-31G(d) basis set. A comparison among the different Phthalocyanine (Pc) derivatives, including Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2) compounds, for the geometry, molecular orbital, and atomic charge was made. The substitution effect of the N atoms and the isotopic effect of D atoms on the properties of these compounds were discussed. The farther the heterocyclic N atoms in the benzo rings from 16-membered ring are, the smaller it influence the size of the central hole, the bond lengths and bond angles of 16-membered ring, the HOMO-LUMO gaps, and the atomic charges on the core Pz fragment. In other words, the properties of TPdPz* compounds are closer to Pc than TPdPz. With the order of H2Pc<TPdPzH2<TPdPzH2*, the acidity of the inner N-H bonds in the three molecules increased in turn.

scholarly journals Electronic structures and photovoltaic properties of a novel phthalocyanine and titanium dioxide phthalocyanine for dye sensitized-solar cells

2021 ◽  
Vol 6 (3) ◽  
pp. 107-115
Author(s):  
Fares A. Yasseen ◽  
Faeq A. Al-Temimei
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Electronic Structures ◽  
Density Functional ◽  
Energy Gap ◽  
Dye Sensitized Solar Cells ◽  
Solar Spectrum ◽  
Electron Injection ◽  
Basis Set ◽  
Functional Theory

In the present work, geometries, electronic structures, photovoltaic and optical properties have been carried out on a series of structures formation of phthalocyanine and Titanylphthalocyanine dyes, which are replaced by several subgroup. A density functional theory (DFT) approach together with hybrid function (B3LYP) at SDD basis set was used for the ground state properties in the gas phase. The time-dependent density functional theory (TD-DFT)/ B3LYP was used to investigate the excitation properties of new dyes and analyzed the trends in their optical and redox characteristics. Theoretical principles of HOMO and LUMO energy levels of dyes is requisite in analyzing organic solar cells, thus, HOMO, LUMO levels, open circuit voltage, energy gap, light harvestings efficiency, electron regeneration and electron injection have been calculated and discussed. The outcome of the efficiency, the considered dyes explain absorption energy and wavelength properties that correspond to the solar spectrum requirements. According to results, all the considered materials have a good property and possibility of electron injection procedure from the dyes to conduction band of TiO2, PC60BM or PC60BM. As a result, the molecular changes affect the electronic properties of dye molecules for solar cells. Also, a study of new dyes sensitizers showed that designed materials will be excellent sensitizers. Theoretical designing will prae a way for experimentalists to synthesize the efficient sensitizers for solar cells clearer.

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