Norbornadiene—Quadricyclane as an Abiotic System for the Storage of Solar Energy

Molecular photoswitches that are capable of storing solar energy, so-called molecular solar thermal storage systems, are interesting candidates for future renewable energy applications. In this context, substituted norbornadiene-quadricyclane systems have received renewed interest due to recent advances in their synthesis. The optical, thermodynamic, and kinetic properties of these systems can vary dramatically depending on the chosen substituents. The molecular design of optimal compounds therefore requires a detailed understanding of the effect of individual substituents as well as their interplay. Here, we model absorption spectra, potential energy storage, and thermal barriers for back-conversion of several substituted systems using both single-reference (density functional theory using PBE, B3LYP, CAM-B3LYP, M06, M06-2x, and M06-L functionals as well as MP2 calculations) and multireference methods (complete active space techniques). Already the diaryl substituted compound displays a strong red-shift compared to the unsubstituted system, which is shown to result from the extension of the conjugated π-system upon substitution. Using specific donor/acceptor groups gives rise to a further albeit relatively smaller red-shift. The calculated storage energy is found to be rather insensitive to the specific substituents, although solvent effects are likely to be important and require further study. The barrier for thermal back-conversion exhibits strong multireference character and as a result is noticeably correlated with the red-shift. Two possible reaction paths for the thermal back-conversion of diaryl substituted quadricyclane are identified and it is shown that among the compounds considered the path via the acceptor side is systematically favored. Finally, the present study establishes the basis for high-throughput screening of norbornadiene-quadricyclane compounds as it provides guidelines for the level of accuracy that can be expected for key properties from several different techniques.

show abstract

“… 17 − 19 Both experimental and theoretical aspects of this research field have been reviewed recently. 6 , 18 , 20 , 21 …”

Section: Introductionmentioning

confidence: 99%

Comparative Ab-Initio Study of Substituted Norbornadiene-Quadricyclane Compounds for Solar Thermal Storage

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The bromine atoms account for more than 25% of the total electrons of the system. If the norbornadienes 8 and 9 are to be studied using ultrafast X-ray scattering techniques, it must first be shown that the norbornadienes 8 and 9 can undergo photolytic isomerisation to the corresponding quadricyclanes 8q and 9q As triplet states are involved in the transformation [7][8][9][10][11][12], the bromine atoms might make the process slow or prevent it from happening. Two photolysis experiments are shown in Figure 3.…”

Section: Resultsmentioning

confidence: 99%

“…In this article, potential candidates for the study of transients in a 2 + 2 cycloaddition reaction with time-resolved X-ray scattering studies in solution and the gas phase are presented. The norbornadiene-quadricyclane system has been investigated as a potential system for solar energy storage [7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Bromosubstituted norbornadienes and their reversible photolytic transformation to quadricyclanes

Sørensen

Madsen

Martin

et al. 2014

ScienceOpen Research

View full text Add to dashboard Cite

Two new model systems for use within the rapidly developing ultrafast time resolved x-ray scattering techniques have been prepared. Their photoisomerisation from norbornadiene to quadricyclane was found to be a suitable reaction to follow. Simulations of scattering patterns (not included in this report) showed that if heavy atoms are included in these molecular structures, then the transformation can be followed by transient x-ray scattering techniques. Two new bromosubstituted norbornadienes were synthesised and characterised. Absorption spectroscopy showed that the norbornadienes are converted quantitatively to quadricyclanes under UV irradiation. NMR studies showed that the process was fully reversible and that the norbornadienes could be completely recovered even without addition of catalysts. Furthermore, it was shown that the formation of quadricyclane from norbornadiene was unaffected by triplet sensitizers. The two new model systems synthesised thus are strong candidates for use in time resolved x-ray scattering studies both in gas and condensed phases.

show abstract

“…Thus, different molecular modifications have been explored to optimize the performance, including the introduction of electron donor and acceptor groups on one or both double bonds. 27 , 29 , 30 , 33 , 34 …”

mentioning

confidence: 99%

“…The presented NBD derivative has already many advantages compared to those of previously reported systems, such as the ease of synthesis 34 and the demonstrated robustness over many cycles. 37 Moreover, NBDs synthesis and physical and chemical behaviors and properties are widely studied and quite well understood, 29 , 32 , 35 , 36 , 38 implying the facilitation of carefully designing molecular systems with the desired properties and predictable physicochemical behavior. Some limitations and challenges can be identified.…”

mentioning

confidence: 99%

Three-Input Molecular Keypad Lock Based on a Norbornadiene–Quadricyclane Photoswitch

Dreos

Wang

Tebikachew

et al. 2018

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

The photo- and acidochromic properties of a new generation norbornadiene derivative have been harnessed for the realization of a three-input keypad lock, where a specific sequence of inputs induces a unique output. Reversible quadricyclane/norbornadiene photoisomerization is reported, and this rare feature allows the first example of a norbornadiene-based molecular logic system. The function of this system is clearly rationalized in terms of the interconversion scheme and the absorption spectra of the involved species.

show abstract

Norbornadiene—Quadricyclane as an Abiotic System for the Storage of Solar Energy

Cited by 13 publications

References 1 publication

Comparative Ab-Initio Study of Substituted Norbornadiene-Quadricyclane Compounds for Solar Thermal Storage

Comparative Ab-Initio Study of Substituted Norbornadiene-Quadricyclane Compounds for Solar Thermal Storage

Bromosubstituted norbornadienes and their reversible photolytic transformation to quadricyclanes

Three-Input Molecular Keypad Lock Based on a Norbornadiene–Quadricyclane Photoswitch

Contact Info

Product

Resources

About