Carbon-13 carbonyl shielding and steric inhibition of resonance a new and better method for estimating angles of twist in conjugated systems

1964 ◽  
Vol 5 (12) ◽  
pp. 631-639 ◽  
Author(s):  
K.S. Dhami ◽  
J.B. Stothers
2020 ◽  
Vol 23 (23) ◽  
pp. 2598-2613
Author(s):  
Boris A. Zaitsev

: A retrospective view of exaltation of refraction observed for many unsaturated and aromatic compounds demonstrates that this physical phenomenon is undeservedly considered only as a qualitative measure of conjugation. This mini-review discusses numerous papers by the author that have been published earlier in inaccessible periodicals and collections of scientific papers. Using a great number of illustrations, the author shows that this parameter can be successfully used for quantitative estimate of resonance effects in organic and polymer chemistry. The methods for derivation of strictly additive atomic and group refraction constants are described; these constants were subsequently used as a tool that allowed quantitative estimation of resonance effects in mono-, di-, tri- and polyalkylbenzenes, alkylnaphthalenes, some alkyl derivatives of unsaturated hydrocarbons. These effects cause strictly fixed increase in refraction of carbon atoms in different structural modifications (graphene, fullerene, diamond) and in polycyclic aromatic hydrocarbons. The relevant results regarding quantitative estimation of degree of steric inhibition of resonance in sterically hindered ortho-dialkylbenzenes, 1,2,3- trialkyl-, 1,2,3,4-tetraalkyl-, and 1,2,3,4,5-polyalkylbenzenes accumulated by the author are summarized.


1978 ◽  
Vol 43 (5) ◽  
pp. 1375-1392 ◽  
Author(s):  
Ante Graovac ◽  
Ivan Gutman ◽  
Milan Randić ◽  
Nenad Trinajstić

2010 ◽  
Vol 49 (38) ◽  
pp. 6764-6767 ◽  
Author(s):  
Xingfa Gao ◽  
Shengbai B. Zhang ◽  
Yuliang Zhao ◽  
Shigeru Nagase

Aggregate ◽  
2021 ◽  
Author(s):  
Xin Deng ◽  
Xiaohui Yu ◽  
Jinchong Xiao ◽  
Qichun Zhang

1998 ◽  
Vol 22 (6) ◽  
pp. 547-549 ◽  
Author(s):  
Philippe Blanchard ◽  
Hugues Brisset ◽  
Ame´de´e Riou ◽  
Rolland Hierle ◽  
Jean Roncali

ChemInform ◽  
2010 ◽  
Vol 30 (13) ◽  
pp. no-no
Author(s):  
Philippe Blanchard ◽  
Hugues Brisset ◽  
Amedee Riou ◽  
Rolland Hierle ◽  
Jean Roncali
Keyword(s):  

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