US EPA

1592928 

Journal Article 

Preparation and study of 1,8-di(pyrid-2'-yl)carbazoles 

Mudadu, MS; Singh, AN; Thummel, RP 

2008 

Yes 

Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904 

73 

17 

6513-6520 

English 

18666796 

10.1021/jo801132w 

WOS:000258908000006 

A series of three derivatives of 1,8-di(pyrid-2'-yl)carbazole were prepared by Stille-type coupling of 2-(tri-n-butylstannyl)pyridine with the appropriate 1,8-dibromocarbazole. The carbazoles were prepared by appropriate substitution methodologies on the parent carbazole or by palladium-catalyzed cyclization of di-(p-tolyl)amine to provide the carbazole ring system. An X-ray structure of the di-tert-butyl derivative confirmed that both pyridyl groups were oriented for favorable intramolecular H-bonding to the central N-H. Two orientations of the molecule were found in the unit cell and this observation was corroborated by two N-H stretching bands in the solid state IR. Substitution of N-H by N-D led to increased emission intensity through diminished intramolecular deactivation of the excited state. The di-tert-butyl derivative formed a tridentate complex with Pd(II), which showed a red-shifted band attributed to an intraligand charge transfer state.