@article {49899,
	title = {(Chiro)optical Properties of π-Extended Spiro-Double Carbo[7]helicene},
	journal = {Journal of Physical Chemistry Letters},
	volume = {16},
	year = {2025},
	month = {NOV },
	pages = {11657-11664},
	type = {Article},
	abstract = {<p>
	Helical nanographenes are a fascinating class of pi-extended chiral nanocarbons, where structural helicity imparts intrinsic chirality and unique optoelectronic properties to the rigid carbon framework. In this work, we synthesized a hexa-peri-hexabenzocoronene-based pi-extended spiro-double carbo[7]helicene. The helical distortion of the structure was unambiguously confirmed by X-ray crystallography. The optical properties were explored through UV-Vis absorption, fluorescence, and phosphorescence measurements, complemented by density functional theory (DFT) calculations. Remarkably, the pi-extended spiro-double carbo[7]helicene exhibited thermally activated delayed fluorescence (TADF) at room temperature and phosphorescence at low temperatures. Chiral HPLC successfully resolved the enantiomers into three fractions: (PP), (MM), and the meso forms (PM)/(MP), and chiroptical studies of the pure enantiomers revealed a moderately high g lum value of 1.58 x 10-3. Finally, the origin of the observed dissymmetry factors was rationalized by analyzing the transition electric dipole moments (TEDM) and transition magnetic dipole moments (TMDM) derived from time-dependent density functional theory (TD-DFT) calculations.</p>
},
	issn = {1948-7185},
	doi = {10.1021/acs.jpclett.5c02897},
	author = {Kumar, Viksit and Dongre, Sangram D. and Vandhanam, Aparna and Jadhav, Ashok Badrinarayan and Kumar, Jatish and Babu, Sukumaran Santhosh}
}
