Angular Group Induced BondAlternation (AGIBA). A New Face of Substituent Effect Detectedin Molecular Geometry

Synlett ◽  
2003 ◽  
pp. 0922-0936 ◽  
Author(s):  
Tadeusz Marek Krygowski ◽  
Micha Ksawery Cyrański
Keyword(s):  
Substituent Effect ◽  
Molecular Geometry

Substituent effect on molecular geometry and aromaticity of symmetric B-trisubstituted borazine

2005 ◽  
Vol 728 (1-3) ◽  
pp. 197-202 ◽  
Author(s):  
Ren Miao ◽  
Gaosheng Yang ◽  
Chunmei Zhao ◽  
Jin Hong ◽  
Longgen Zhu
Keyword(s):  
Substituent Effect ◽  
Molecular Geometry

scholarly journals Synthesis of amphiphilic asymmetrical dithienylethenes with aryl groups at the reactive carbons

2019 ◽  
Vol 97 (6) ◽  
pp. 398-405
Author(s):  
M.S. Jemeli Sang ◽  
Jianxin Cai ◽  
Yamuna S. Kandasamy ◽  
R. Scott Murphy
Keyword(s):  
Steric Hindrance ◽  
Substitution Reaction ◽  
Substituent Effect ◽  
Large Change ◽  
Molecular Geometry ◽  
Methyl Groups ◽  
Synthetic Route ◽  
Aryl Substituent ◽  
Aryl Group ◽  
Enhanced Photostability

A synthetic route for the preparation of amphiphilic asymmetrical dithienylethenes that incorporate methyl groups at the 4- and 4′-positions and an aryl group at one of the reactive carbons has been developed. The presence of a bulky aryl substituent ensures a relatively large change in molecular geometry upon photoisomerization, whereas the presence of methyl groups provide enhanced photostability. Notably, a substituent effect was systematically revealed en route to the preparation of the dithienylethene precursors. In particular, this formal substitution reaction was significantly inhibited due to steric hindrance, stemming from the presence of aryl and methyl groups at the alpha positions of the preformed thienyl carbanionic carbon, and an aryl group on the monosubstituted perfluorocyclopentene derivative.

Theoretical study of intramolecular hydrogen bonding and molecular geometry of 2-trifluoromethylphenol

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai
Keyword(s):  
Hydrogen Bonding ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

Substituent effect on wave numbers of C=O valence vibrations in ferrocene derivatives

1983 ◽  
Vol 48 (6) ◽  
pp. 1635-1646 ◽  
Author(s):  
Alexander Perjéssy ◽  
Štefan Toma
Keyword(s):  
Linear Correlation ◽  
Substituent Effect ◽  
Empirical Relation ◽  
Ferrocene Derivatives ◽  
Wave Numbers ◽  
Complex Structural ◽  
Transmission Factors

Wave numbers of C=O valence vibrations of 83 ferrocene derivatives have been measured in tetrachloromethane. For a series of 154 compounds containing ferrocene skeleton linear correlation has been found between wave numbers of C=O vibration and X+(R) constants of structural fragments in the sense of modified and extended Seth-Paul-Van Duyse equation. Validity has been verified of the recently derived empirical relation for calculation of the X+(R) constants of complex structural fragments from values of constants of substituents and transmission factors for simple structural groupings. The transmission factors γ and π' for 1,3- and 1,1'-ferrocene system have been found to be well applicable to calculation of constants of structural fragments containing ferrocene skeleton.

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