Weber Roza R, Stindt Charlotte N, van der Harten A M J, Feringa Ben L
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands.
Chemistry. 2024 Jun 20;30(35):e202400482. doi: 10.1002/chem.202400482. Epub 2024 Apr 17.
The norbornadiene/quadricyclane (NBD/QC) photoswitch pair represents a promising system for application in molecular solar thermal energy storage (MOST). Often, the NBD derivatives have very limited overlap with the solar spectrum, and substitution to redshift the absorption leads to a decrease in the gravimetric energy density. Dimeric systems mitigate this factor because two switches can 'share' a substituent. Here, we present five new NBD dimers with red-shifted absorption spectra. One dimer features the most red-shifted absorption onset (539 nm) and a significantly red-shifted absorption maximum (404 nm) for NBD systems reported so far, without compromising thermal half-life. Promising properties for high-performance MOST applications are demonstrated, such as high absorption onsets reaching 539 nm, and energy densities of 379 kJ/kg, while still maintaining long half-lives of the metastable isomer, up to 23 hours at 25 °C.
降冰片二烯/四环烷（NBD/QC）光开关对是一种很有前景的用于分子太阳能热能存储（MOST）的体系。通常，NBD衍生物与太阳光谱的重叠非常有限，并且为了使吸收发生红移而进行的取代会导致重量能量密度降低。二聚体体系缓解了这一因素，因为两个光开关可以“共享”一个取代基。在此，我们展示了五种具有红移吸收光谱的新型NBD二聚体。其中一种二聚体具有目前报道的NBD体系中最红移的吸收起始波长（539 nm）和显著红移的吸收最大值（404 nm），同时不影响热半衰期。展示了其在高性能MOST应用中的良好性能，例如高达539 nm的高吸收起始波长，以及379 kJ/kg的能量密度，同时仍保持亚稳异构体的长半衰期，在25 °C下长达23小时。
