Increased Coplanarity and Conjugation and Lowered HOMO-LUMO Energy Differences in Benzochalogens Connected to Aromatic Substituents via Ethynyl Spacers: A DFT Study

2013 ◽  
Author(s):  
Michael R. Korn ◽  
Ron Pieper ◽  
Jianmin Shi
Keyword(s):  
Dft Study ◽  
Lumo Energy ◽  
Homo Lumo

scholarly journals A DFT study on dihydropyrazine annulated linear polyacenes: aromaticity, stability and HOMO–LUMO energy modulation

2016 ◽  
Vol 18 (35) ◽  
pp. 24631-24641 ◽  
Author(s):  
Ramachandran Rakhi ◽  
Cherumuttathu H. Suresh
Keyword(s):  
Dft Study ◽  
Lumo Energy ◽  
Aromatic Character ◽  
Lone Pairs ◽  
Energy Modulation ◽  
Homo Lumo

Linear polyacene (LPA) mimics containing up to 34 rings have been designed by annulating dihydropyrazine units to LPA cores and they showed enhanced aromatic character than the LPA due to significant mixing of the N-lone pairs with the carbon π-orbitals.

DFT study of conjugated biheterocyclic oligomers exhibiting a very low HOMO–LUMO energy gap

2004 ◽  
Vol 140 (2-3) ◽  
pp. 127-133 ◽  
Author(s):  
Hafida Ammar Aouchiche ◽  
Sema Djennane ◽  
Abdou Boucekkine
Keyword(s):  
Energy Gap ◽  
Dft Study ◽  
Lumo Energy ◽  
Homo Lumo

DFT STUDY OF COFn(n = 1-6) NANO CLUSTERS: AN INVESTIGATION OF SUPERHALOGEN PROPERTIES

2012 ◽  
Vol 11 (04) ◽  
pp. 723-734 ◽  
Author(s):  
SHAMOON AHMAD SIDDIQUI
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Dft Study ◽  
Anionic Form ◽  
Electron Affinities ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo ◽  
Peak Value

Superhalogen properties of CoFn (n = 1 - 6) clusters have been investigated using density functional theory. These calculations reveal the unusual properties of a Cobalt (Co) atom interacting with fluorine (F) atoms. Up to six F atoms are bound to a single Co atom, which results in increase of electron affinities as successive fluorine atoms are attached, reaching a peak value of 7.43 eV for CoF5 . The large HOMO–LUMO energy gap, both in neutral and anionic form, further provide evidence of their stability. These unusual properties brought about by involvement of inner shell 3d-electrons, which not only allow CoFn (n = 1 - 6) clusters to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 2 or 3.

A p–n fusion strategy to design bipolar organic materials for high-energy-density symmetric batteries

2021 ◽  
Author(s):  
Jihyeon Kim ◽  
Heechan Kim ◽  
Sechan Lee ◽  
Giyun Kwon ◽  
Taewon Kang ◽  
...  
Keyword(s):  
Energy Density ◽  
Organic Material ◽  
Energy Gap ◽  
High Energy ◽  
High Energy Density ◽  
Lumo Energy ◽  
Fusion Strategy ◽  
Redox Active ◽  
Bipolar Type ◽  
Homo Lumo

A new bipolar-type redox-active organic material with a wide HOMO–LUMO energy gap is designed though the ‘p–n fusion’ strategy.

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

Synthesis and Characterization of a Methanofullerene-4-Fluoro-α-Cyanostilbene Dyad as a Potential Acceptor for Organic Solar Cells

2015 ◽  
Vol 1784 ◽  
Author(s):  
Venkata Neti
Keyword(s):  
Mass Spectrometry ◽  
Cyclic Voltammetry ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Synthesis And Characterization ◽  
Lumo Energy ◽  
Homo Lumo ◽  
Aryl Ester

ABSTRACTA series of fluorine appended highly conjugated fullerenes were prepared containing fluoro-α-cyanostilbene and aryl ester units. These modified PCBM dyads are fully characterized by NMR, Mass spectrometry, UV-vis, and cyclic voltammetry (Figures 1-4). It was found that the presence of fluoro-α-cyanostilbenes and esters affects the cyclic voltammetry and absorption in the UV-Vis region. The PCBA modified fullerenes significantly influences the HOMO-LUMO energy and wide absorption compared to PCBM.

A detailed investigation into the geometric and electronic structures of CoBQn (n = 2–10, Q = 0, −1) clusters

2017 ◽  
Vol 41 (19) ◽  
pp. 11208-11214 ◽  
Author(s):  
Peifang Li ◽  
Guoliang Sun ◽  
Jianping Bai ◽  
Weihua Wang ◽  
Gang Bao ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Size Dependence ◽  
Lumo Energy ◽  
Boron Clusters ◽  
Energy Gaps ◽  
Homo Lumo ◽  
Co Doped

The size dependence of HOMO–LUMO energy gaps of Co doped boron clusters.

scholarly journals Electronic Structure of Two New Bis-Schiff Base Ligands using DFT Method

2021 ◽  
pp. 10-15
Author(s):  
Elham Abdalrahem Bin Selim ◽  
Mohammed Hadi Al–Douh ◽  
Hassan Hadi Abdullah ◽  
Dahab Salim Al–Nohey
Keyword(s):  
Experimental Data ◽  
Biological Activity ◽  
Metal Ion ◽  
Energy Levels ◽  
Dft Method ◽  
Ftir Spectra ◽  
Schiff Base Ligands ◽  
Lumo Energy ◽  
Homo Lumo ◽  
Good Agreement

Two bis-Schiff Bases 1 and 2 are ligands that can coordinate with manganese metal to form stable complexes and have biological activity. Thermodynamic parameters, HOMO-LUMO energy levels and FTIR spectra of two ligands have been computed using B3LYP/6-311++G(d,p) functional of the DFT calculations. Both ligands are favored thermodynamically, and the ligand 1 has been shown to be more stable than ligand 2. The Polarizability values of two ligands have been investigated. The results refer that ligand 2 interacts earlier than ligand 1 to the metal ion. The FTIR spectra of two ligands have been evaluated. All results show the good agreement between the theoretical and experimental data.

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