A pentacene with a 144 degrees twist.
J Am Chem Soc
; 126(36): 11168-9, 2004 Sep 15.
Article
in En
| MEDLINE
| ID: mdl-15355095
ABSTRACT
9,10,11,20,21,22-Hexaphenyltetrabenzo[a,c,l,n]pentacene (1) was prepared by the reaction of 1,3-diphenylphenanthro[9,10-c]furan with the bisaryne equivalent generated from 1,2,4,5-tetrabromo-3,6-diphenylbenzene in the presence of n-butyllithium, followed by deoxygenation of the double adduct with low-valent titanium. The X-ray structure of 1 shows it to be the most highly twisted polycyclic aromatic hydrocarbon known, with an end-to-end twist of 143.6 degrees . Compound 1 was resolved by chromatography on a chiral support, and the pure enantiomers have specific rotations in excess of 7000 degrees , but the molecule racemizes slowly at 25 degrees C (t1/2 = 9.3 h, DeltaGrac = 23.8 kcal/mol).
Search on Google
Database:
MEDLINE
Main subject:
Polycyclic Aromatic Hydrocarbons
Language:
En
Journal:
J Am Chem Soc
Year:
2004
Type:
Article
Affiliation country:
United States