ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Pyrylium Compounds. XIV. The Light Absorption of 1,2-Benzoxalenes (Indeno[2,1-b]pyrans)The iso-π-electronic relationship between azulene A and the heterocyclic pseudoazulene B is reflected by the same dependence of the N—V1 transition from the substituents: Many examples (1-27) show that pseudo-azulenes of the 1,2-benzoxalene type (indeno[2,1-b]pyran) C undergo a bathochromic shift by alkyl substitution at C3 and C6, but an hypsochromic shift by alkyl substitution at C7. Second order substituents effect an opposite influence (examples 92-98). The conjugative effect of substituents causes a bathochromic shift in all positions (examples 49-58), which may rise to a remarkable amount with the extension of the conjugated system (examples 59-91). The relations obtained correspond to the results of quantum-chemical calculations (examples 28-48).
Additional Material:
6 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19783200313
