Related Experiment Video
Updated: May 11, 2026

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems
Published on: February 10, 2020
Ultrafast spectroscopy of linear carbon chains: the case of dinaphthylpolyynes
D Fazzi1, F Scotognella, A Milani
1Center for Nano Science and Technology CNST@Polimi, Istituto Italiano di Tecnologia, Milano, Italy.
Abstract:
The dynamics of excited states in α,ω-dinaphthylpolyyne, a class of linear sp-carbon chains, has been investigated by ultrafast transient absorption spectroscopy and DFT//TDDFT calculations. We show that the role of molecular conformers, in which end-capped naphthalene rings are planar or perpendicular to the polyyne plane, is fundamental for understanding both the steady state properties, such as UV-Vis absorption spectra and vibronic transitions, and the ultrafast transient absorption features. In particular, we observed in one of the conformers the ultrafast formation of a narrow photo-induced absorption band rising within 30 ps. This band can be assigned to an inter-system crossing event leading to the formation of triplet excited states.
Related Concept Videos
UV–Vis Spectroscopy: Woodward–Fieser Rules
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Spectroscopy of Carboxylic Acid Derivatives
In the...
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...
UV–Vis Spectroscopy: Molecular Electronic Transitions
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...

