Origin of the size-dependent fluorescence blueshift in [n]cycloparaphenylenes

Describing excited states of [n]cycloparaphenylenes by hybrid and double-hybrid density functionals: from isolated to weakly interacting molecules

“…The absorption spectra of [n]CPPs was later recorded, showing however a nearly-constant peak at around 3.65 eV independently of system size and/or solvent effects [34]. These results were rationalized in terms of an optically forbidden singlet excited-state of lowest energy, S 1 , and thus with a vanishing oscillator strength, and two degenerate (quasi-degenerate) states slightly higher in energy and dubbed as S 2 and S 3 in even (odd) nanocycles showing large oscillator strength values [35,36]. The corresponding lowest triplet excited-state of some of these compounds have been also investigated showing size-dependent trends similar to the S 1 case [37].…”

Singlet and triplet excitons and charge polarons in cycloparaphenylenes: a density functional theory study

“…1 However, the efficient high-yield synthesis of these molecules was pioneered by Jasti and co-workers in 2008. 9,[15][16][17][18][19] Owing to the potential application as seeds for growing the single chirality metallic carbon nanotubes, 20 being efficient emitters with tunable wavelength, 13,21 and having a unique structure that inspired the synthesis of hoops with alternative building blocks 22 and cage-like structures, 23,24 CPPs very quickly acquired world-wide attention. 9,[15][16][17][18][19] Owing to the potential application as seeds for growing the single chirality metallic carbon nanotubes, 20 being efficient emitters with tunable wavelength, 13,21 and having a unique structure that inspired the synthesis of hoops with alternative building blocks 22 and cage-like structures, 23,24 CPPs very quickly acquired world-wide attention.…”

Intra‐ and Intermolecular Dispersion Interactions in [n]Cycloparaphenylenes: Do They Influence Their Structural and Electronic Properties?

“…Actually, the strongest maximum absorption (λ max ) for this molecule does not originate from a HOMO to LUMO transition, but involves few transitions and peaks at around 340 nm independently of solvent effects [59]. Note that the vibronic effects on these optical properties have been recently investigated [63,64]. We have thus calculated, at the TimeDependent (TD) DFT level and with the same functional (B3LYP) and basis set (6-31+G*) than those used before for obtaining the ground-state geometry, the TD-B3LYP/6-31+G* level, the lowest vertical absorption energy showing a non-negligible oscillator strength.…”