Related Experiment Video
Updated: May 14, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Tuning photoinduced processes of covalently bound isoalloxazine and anthraquinone bichromophores
Angeles Farrán1, John Mohanraj, Guy J Clarkson
1Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, Paseo Senda del Rey 9, 28040 Madrid, Spain. afarran@ccia.uned.es
Abstract:
We present here the synthesis of several new isoalloxazine cyclophanes containing electroactive anthraquinones linked by aliphatic chains of different lengths. Such structural changes provide different interchromophoric orientations leading to the tuning of the rate of the photoinduced electron transfer process from the anthraquinone unit towards the isoalloxazine singlet excited state. Molecular modelling studies were undertaken in order to determine the minimal energy of the proposed structures using Monte Carlo calculations (Amber, Macromodel v.8.1). The compounds have been fully characterised by NMR spectroscopy and the solid state structures of some of the macrocycles have been elucidated. The photophysical studies have been carried out in order to investigate the influence of π-π stacking on the optical properties of the macrocycles.
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Cycloaddition Reactions: MO Requirements for Photochemical Activation
The Photochemical Reaction Center
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
The Antenna Complex

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)