Photolytic Studies of Norbornadiene Derivatives under High-Intensity Light Conditions
Artikel i vetenskaplig tidskrift, 2022

The photoconversion of a norbornadiene (NBD) derivative was studied under high-intensity mono- and polychromatic light conditions at high concentrations. The photoisomerization quantum yield (φNBD→QC), proceeding from NBD to its quadricyclane (QC) isomer, was determined using a tunable OPO laser and a solar simulator light source. The solar simulator was designed to mimic the AM1.5G solar spectrum between 300 and 900 nm. Using the OPO laser, φNBD→QC was measured at discrete values between 310 and 350 nm in steps of 10 nm, and a variation between 0.81 and 0.96 was observed. Weighting these values of φNBD→QC with the spectral profile of the solar simulator, an averaged value of 0.87 ± 0.03 was obtained. Determination of φNBD→QC was also performed directly in the solar simulator providing a value of 0.97 ± 0.14, in good agreement with the weighted values from the OPO. Photoisomerization quantum yields were found to decrease slightly at higher concentrations. At high concentrations, we found that correcting for the presence of QC was important due to similar absorption coefficients of the NBD and QC isomers at the absorption tail. Cyclability of the forward and backward NBD/QC conversion was studied over several cycles. The NBD/QC couple exhibited excellent thermal stability, but a slight photodegradation per cycle was observed, increasing with the concentration of the sample. This result indicates that the molecules undergo some intermolecular reactions.

Författare

Alexander Kjaersgaard

Köpenhamns universitet

Helen Hölzel

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Kasper Moth-Poulsen

Institucio Catalana de Recerca i Estudis Avancats

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)

M. B. Nielsen

Köpenhamns universitet

Journal of Physical Chemistry A

1089-5639 (ISSN) 1520-5215 (eISSN)

Vol. 126 39 6849-6857

Ämneskategorier

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

Annan fysik

DOI

10.1021/acs.jpca.2c03583

PubMed

36149432

Mer information

Senast uppdaterat

2024-03-07