Indenofluorene congeners: Biradicaloids and beyond

2014 ◽  
Vol 86 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Akihiro Shimizu ◽  
Shunpei Nobusue ◽  
Hirokazu Miyoshi ◽  
Yoshito Tobe
Keyword(s):  
Physical Properties ◽  
Ground State ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Triplet Energy ◽  
Lumo Energy ◽  
Energy Gaps ◽  
Electronic Configurations ◽  
Homo Lumo

Abstract Singlet biradicaloids are certainly one of the most frequently discussed topics at ISNA-15. In this review our own work on the synthesis, molecular structures, and physical properties relevant to biradical character of indenofluorene isomers are described. These include indeno[2,1-a]fluorene with an o-quinodimethane substructure, benz[c]indeno[2,1-a]fluorene which is the first 2,3-naphthoquinodimethane derivative isolated, and indeno[2,1-b]fluorene with an m-quinodimethane (m-xylylene) subunit. The observed physical properties are explained in terms of the theoretically derived biradical factors (y), HOMO-LUMO energy gaps, and singlet-triplet energy gaps in the ground state electronic configurations. In addition, we discuss here two perspectives in the biradicaloid chemistry, (i) two- and three-dimensional indenofluorene congeners arranged in a macrocyclic form and (ii) macrocyclic indenofluorenes having multiple radical characters.

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 5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Hydrogen Atoms ◽  
Lumo Energy ◽  
Compound C ◽  
Dansyl Group ◽  
Weak Hydrogen Bonds ◽  
Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

Dispiroacridine-indacenobisthiophenes positional isomers: Impact of the bridge on the physicochemical properties

2021 ◽  
Author(s):  
Jean-David Peltier ◽  
Benoît Heinrich ◽  
Bertrand Donnio ◽  
Olzhas A. Ibraikulov ◽  
Thomas Heiser ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Physicochemical Properties ◽  
Physical Properties ◽  
Charge Transport ◽  
Energy Levels ◽  
Molecular Organization ◽  
Positional Isomers ◽  
Lumo Energy ◽  
Positional Isomerism ◽  
Homo Lumo

We report the influence of positional isomerism on the electronic (electrochemical HOMO/LUMO energy levels), photophysical and physical properties (molecular organization, crys¬¬tallinity and phase transitions) and charge transport properties of dispiroacridine-in¬da¬ce¬no¬bis¬thio¬phene...

Meso-alkynyl corroles and their cobalt(III), manganese(III) and gallium(III) complexes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 737-749
Author(s):  
Michael Haas ◽  
Sabrina Gonglach ◽  
Wolfgang Schöfberger
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Lumo Energy ◽  
Functional Theory ◽  
Energy Gaps ◽  
Peak Broadening ◽  
Homo And Lumo ◽  
Homo Lumo

We report routes towards synthesis of novel [Formula: see text]-conjugated freebase cobalt, copper, gallium and manganese meso-alkynylcorroles. UV-vis spectra show that extensive peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of [Formula: see text]-conjugation. Using density functional theory (DFT), we have carried out a first theoretical study of the electronic structure of these metallocorroles. Decreased energy gaps of about 0.3–0.4 eV between the HOMO and LUMO orbitals compared to the corresponding copper, gallium and manganese meso-5,10,15 triphenylcorrole are observed. In all cases, the HOMO energies are nearly unperturbed as the [Formula: see text]-conjugation is expanded. The contraction of the HOMO–LUMO energy gaps is attributed to the lowered LUMO energies.

Synthesis of Novel Substituted 1,5-Benzothiazepines Containing 1,4-Benzodioxane Sulfonyl Moiety

2019 ◽  
Vol 4 (2) ◽  
pp. 70-76
Author(s):  
Sandhya Chhakra ◽  
A. Mukherjee ◽  
H.L. Singh ◽  
Suresh Singh Chauhan
Keyword(s):  
13C Nmr ◽  
Ground State ◽  
Mobile Phase ◽  
Energy Gap ◽  
Sulfonyl Chloride ◽  
Frontier Molecular Orbitals ◽  
Efficient Synthesis ◽  
Lumo Energy ◽  
Mass Spectral ◽  
Homo Lumo

An efficient synthesis of novel 2,3,4-trisubstituted 1,5-benzothiazepines (4a-e) incorporating the sulfonyl group is described. Compound (4a-e) was synthesized by the reaction of 3-(1,4-dioxane-6-sulfonyl)-2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (3ae) with 2-aminobenzenethiol with ZnOnanoparticles/pyridine. Formation of compound (3a-e) was achieved by the reaction of 1,4-dioxane-6-sulfonyl chloride (1) with 2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (2a-e). The benzothiazepines (4a-e) obtained were purified by column chromatography (benzene: CHCl3, 40:60, 30:70, 20:80, 10:90) and crystallized from methanol. The purity of the compounds was checked by TLC using (CHCl3: CH3OH, 9:1) as the mobile phase. The structure of the compounds has been established by elemental, IR, 1H NMR, 13C NMR and Mass spectral analyses. Frontier molecular orbitals of the title compounds have been studied in the ground state speculatively. The reactivity of a molecule using diverse descriptors such as softness, electrophilicity, electronegativity, HOMO-LUMO energy gap is calculated additionally discussed.

Saturated N,X-Heterocyclic Carbenes (X=N, O, S, P, Si, C, and B): Stability, Nucleophilicity, and Basicity

2015 ◽  
Vol 68 (9) ◽  
pp. 1438 ◽  
Author(s):  
Zahra Azizi ◽  
Mehdi Ghambarian ◽  
Mohammad A. Rezaei ◽  
Mohammad Ghashghaee
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Energy Difference ◽  
Heterocyclic Carbenes ◽  
Structure Stability ◽  
Triplet Energy ◽  
Lumo Energy ◽  
Dft Methods ◽  
Functional Theory ◽  
Homo Lumo

Various saturated five-membered N,X-heterocyclic carbenes (X = N, O, S, P, Si, C, and B) have been studied by ab initio and density functional theory (DFT) methods. The substitutions alter the properties of the reference carbene from the viewpoint of electronic structure, stability, nucleophilicity, and basicity. Our study shows that the oxygen containing carbene (X = O) induces the highest HOMO–LUMO energy gap (ΔEHOMO–LUMO), while carbene with X = N has the widest singlet–triplet energy difference (ΔEs–t). The nucleophilicity of the carbene derivatives increased upon replacement of C, Si, and B, with the effect of the boron substituent being more pronounced. In addition, the basicity of the structure increased for the carbene derivatives with X = C and B with the latter substitution imposing a remarkably higher effect. Moreover, the substitution of boron at the α-position of the carbene increased the nucleophilicity and basicity, while inducing a reduction in the values of ΔEs–t and ΔEHOMO–LUMO.

scholarly journals Crystal structure and DFT study of a zinc xanthate complex

2019 ◽  
Vol 75 (11) ◽  
pp. 1582-1585 ◽  
Author(s):  
Adnan M. Qadir ◽  
Sevgi Kansiz ◽  
Necmi Dege ◽  
Georgina M. Rosair ◽  
Igor O. Fritsky
Keyword(s):  
Molecular Structure ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Energy Gap ◽  
Three Dimensional ◽  
Intramolecular Interactions ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo

In the title compound, bis(2-methoxyethyl xanthato-κS)(N,N,N′,N′-tetramethylethylenediamine-κ2 N,N′)zinc(II) acetone hemisolvate, [Zn(C4H7O2S2)2(C6H16N2)]·0.5C3H6O, the ZnII ion is coordinated by two N atoms of the N,N,N′,N′-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. The amine ligand is disordered over two orientations and was modelled with refined occupancies of 0.538 (6) and 0.462 (6). The molecular structure features two C—H...O and two C—H...S intramolecular interactions. In the crystal, molecules are linked by weak C—H...O and C—H...S hydrogen bonds, forming a three-dimensional supramolecular architecture. The molecular structure was optimized using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level. The smallest HOMO–LUMO energy gap (3.19 eV) indicates the suitability of this crystal for optoelectronic applications. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules. Half a molecule of disordered acetone was removed with the solvent-mask procedure in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst. 42, 339–341] and this contribition is included in the formula.

Basis set effects on relative energies and HOMO–LUMO energy gaps of fullerene C36

2005 ◽  
Vol 113 (4) ◽  
pp. 233-237 ◽  
Author(s):  
Kyoung Hoon Kim ◽  
Young-Kyu Han ◽  
Jaehoon Jung
Keyword(s):  
Basis Set ◽  
Lumo Energy ◽  
Energy Gaps ◽  
Homo Lumo

The six-membered-ring azomethineN-((E)-{5-[(E)-(pyridin-3-ylimino)methyl]thiophen-2-yl}methylidene)pyridin-3-amine

2013 ◽  
Vol 69 (10) ◽  
pp. 1196-1199 ◽  
Author(s):  
Andréanne Bolduc ◽  
Stéphane Dufresne ◽  
W. G. Skene
Keyword(s):  
Energy Gap ◽  
Three Dimensional ◽  
Energy Difference ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonding ◽  
Lumo Energy ◽  
Azomethine Group ◽  
Compound C ◽  
The Mean ◽  
Homo Lumo

The title compound, C16H12N4S, forms a three-dimensional layered network structureviaintermolecular hydrogen bonding and π-stacking. The azomethine molecule adopts the thermodynamically stableEregioisomer and the pyridine substituents are antiperiplanar. The mean planes of the pyridine rings and the azomethine group to which they are connected are twisted by 27.27 (5) and 33.60 (5)°. The electrochemical energy gap of 2.3 eV based on the HOMO–LUMO energy difference is in agreement with the spectroscopically derived value.

Synthesis and characterization of a new meso-tetra-dihydro benzocyclobutacenaphthylene free-base porphyrin

2018 ◽  
Vol 22 (01n03) ◽  
pp. 173-180 ◽  
Author(s):  
Ümit İşci ◽  
Sevinc Zehra Topal ◽  
Emel Önal ◽  
İsmail Fidan ◽  
Savaş Berber ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Synthesis And Characterization ◽  
Free Base ◽  
Frontier Orbitals ◽  
Lumo Energy ◽  
Energy Gaps ◽  
Homo Lumo

A meso-tetra-6b,10b-dihydrobenzo[j]cyclobut[a]acenaphthylene free-base porphyrin was synthesised and its photophysical, photochemical and electrochemical properties were compared with those of free-base meso-tetraphenylporphyrin. The frontier orbitals and the HOMO–LUMO energy gaps of both compounds were also determined. It was demonstrated that the meso6b,10b-Dihydrobenzo[j]cyclobut[a]acenaphthylene porphyrin retained the same properties as the tetraphenylporphyrin.

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