meso-Aryl-Substituted Subporphyrins:  Synthesis, Structures, and Large Substituent Effects on Their Electronic Properties

2007 ◽  
Vol 129 (15) ◽  
pp. 4747-4761 ◽  
Author(s):  
Yasuhide Inokuma ◽  
Zin Seok Yoon ◽  
Dongho Kim ◽  
Atsuhiro Osuka
Keyword(s):  
Electronic Properties ◽  
Substituent Effects ◽  
Large Substituent

Substituent effects on the electronic properties of complexes with dipyridophenazine and triazole ligands: Electronically connected and disconnected ligands

2015 ◽  
Vol 282-283 ◽  
pp. 33-49 ◽  
Author(s):  
Holly van der Salm ◽  
Anastasia B.S. Elliott ◽  
Keith C. Gordon
Keyword(s):  
Electronic Properties ◽  
Substituent Effects

Substituent effects on geometric and electronic properties of iron tetraphenylporphyrin: a DFT investigation

2011 ◽  
Vol 18 (6) ◽  
pp. 2483-2491 ◽  
Author(s):  
Lu Wei ◽  
Yuanbin She ◽  
Yanmin Yu ◽  
Xiaoqian Yao ◽  
Suojiang Zhang
Keyword(s):  
Electronic Properties ◽  
Substituent Effects ◽  
Geometric And Electronic Properties

Structural influences impacting the role of the 9-ylidene bond in the electronic tuning of structures built upon 9-fluorenylidene scaffolds

2013 ◽  
Vol 91 (11) ◽  
pp. 1059-1071 ◽  
Author(s):  
Galen L. Eakins ◽  
Matthew W. Cooper ◽  
Nikolay N. Gerasimchuk ◽  
Terry J. Phillips ◽  
Bryan E. Breyfogle ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Substituent Effects ◽  
Effect Study ◽  
Semiconducting Materials ◽  
Structural Variations ◽  
Steric Strain ◽  
Exciton Coupling ◽  
Electronic Tuning ◽  
Homo Lumo

A structure–effect study is presented pertaining to the HOMO–LUMO tuning of compounds built upon the 9-fluorenylidene scaffold frequently incorporated as a moiety within organic-based semiconducting materials. The results represent the first reported analysis employing an ensemble of spectroscopy, electrochemistry, and crystal structure data to elucidate and compare the electronic properties of 9-fluorenones, 9-fluorenylidenes, and 9-fluorenimine derivatives. The results also provide the first spectroscopically and crystallographically measured description of exciton coupling within 9,9′-bifluorenylidenes. The 9-ylidene bond is seen to play a key role impacting the electronic properties, and an examination of the effects of substituents, conjugation, heteroatoms, and steric strain on the 9-ylidene bond in a diverse set of structures with representative structural variations relevant to the HOMO–LUMO tuning is presented. Increasing conjugation decreased the HOMO–LUMO gap (HLG), increased the HOMO energy (EHOMO), but decreased the LUMO energy (ELUMO). Substituent effects were observed to produce only slight changes that tended to decrease the HLG and increase both EHOMO and ELUMO, while heteroatom inclusion at the 9-ylidine bond tended to decrease the HLG, EHOMO, ELUMO, and the extinction coefficient. In the sterically hindered 9,9′-bifluorenylidenes, increased steric strain that promoted either an increase in the torsion angle or bond length of the 9-ylidene bond was seen to decrease the HLG via exciton coupling. These results elucidate the HOMO–LUMO tuning of systems containing a 9-fluorenylidene moiety and may assist in developing materials with specifically tuned HLGs and HOMO–LUMO levels for a variety of applications.

ChemInform Abstract: Substituent Effects on the Electronic Properties of Complexes with Dipyridophenazine and Triazole Ligands: Electronically Connected and Disconnected Ligands

ChemInform ◽  
2015 ◽  
Vol 46 (26) ◽  
pp. no-no
Author(s):  
Holly van der Salm ◽  
Anastasia B. S. Elliott ◽  
Keith C. Gordon
Keyword(s):  
Electronic Properties ◽  
Substituent Effects

scholarly journals Theoretical analysis of [5.5.6]cyclacenes: electronic properties, strain energies and substituent effects

2015 ◽  
Vol 17 (11) ◽  
pp. 7366-7372 ◽  
Author(s):  
Birgit Esser
Keyword(s):  
Theoretical Analysis ◽  
Band Gap ◽  
Electronic Properties ◽  
Substituent Effects ◽  
Ground States ◽  
Closed Shell ◽  
Band Gaps ◽  
Low Band Gap ◽  
Effect Of Substituents ◽  
Electronic Ground

[5.5.6]nCyclacenes are proposed as low band gap, closed-shell materials and theoretically investigated regarding their structures, strain energies, aromaticity, electronic ground states, band gaps, and the effect of substituents.

scholarly journals Catalytic, asymmetric difluorination of alkenes to generate difluoromethylated stereocenters

Science ◽  
2016 ◽  
Vol 353 (6294) ◽  
pp. 51-54 ◽  
Author(s):  
Steven M. Banik ◽  
Jonathan William Medley ◽  
Eric N. Jacobsen
Keyword(s):  
Molecular Recognition ◽  
Electronic Properties ◽  
Hydrogen Fluoride ◽  
Substituent Effects ◽  
Temperature Dependent ◽  
Aryl Iodide ◽  
Catalytic Asymmetric ◽  
Quaternary Stereocenters ◽  
Polar Functional Groups ◽  
Wide Assortment

Difluoromethyl groups possess specific steric and electronic properties that invite their use as chemically inert surrogates of alcohols, thiols, and other polar functional groups important in a wide assortment of molecular recognition processes. We report here a method for the catalytic, asymmetric, migratory geminal difluorination of β-substituted styrenes to access a variety of products bearing difluoromethylated tertiary or quaternary stereocenters. The reaction uses commercially available reagents (m-chloroperbenzoic acid and hydrogen fluoride pyridine) and a simple chiral aryl iodide catalyst and is carried out readily on a gram scale. Substituent effects and temperature-dependent variations in enantioselectivity suggest that cation-π interactions play an important role in stereodifferentiation by the catalyst.

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