Related Experiment Video
Updated: Oct 5, 2025

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Isolation and Structural Characterization of Regioisomers of Dibrominated Terrylene Diimides
Shivangee Jha1, Kundan Singh Mehra1, Avantika Hasija1
1Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhopal 462066, India.
Abstract:
Diverse applications of rylenediimides are attributed to the accessibility of simple methodologies to obtain versatile halogenated precursors. Terrylene diimides are important molecular platforms to achieve materials with NIR absorption and emission. In this work, we present a simple synthesis for the hitherto unknown di- and tribromo-TDIs. Regioisomerically pure dibromo TDIs, including an elusive 1,14-derivative, could be successfully isolated and structurally characterized along with tribromo-TDI. The utility of these bromo derivatives has also been demonstrated with a redox anchoring.
Related Concept Videos
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...

