Get a better glimpse on sequential photoreactions of trisnorbornadienes with ¹⁹F NMR spectroscopy

• Julian Felix Maria Hebborn,
• Ben Eric Merten,
• Thomas Paululat and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 527–534, doi:10.3762/bjoc.22.38

• thermal energy storage; photochemistry; photochromism; quadricyclanes; Introduction Photochromic compounds, which change their physical and chemical properties reversibly upon irradiation, figure as a versatile basis for the development of functional materials, whose performance can be switched or

• analysis. Contrary to the 1H NMR spectra, the 19F NMR spectra show significantly fewer characteristic and sufficiently separated signals that allow the unambiguous identification of all photoproducts and, thus, their detection in the course of the photoreaction. Keywords: fluoroarenes; molecular solar

Solar thermal fuels: azobenzene as a cyclic photon–heat transduction platform

• Jie Yan,
• Shaodong Sun,
• Minghao Wang and
• Si Wu

Beilstein J. Org. Chem. 2025, 21, 2036–2047, doi:10.3762/bjoc.21.159

• capable of efficient charging and discharging in the solid state or via photoinduced solid–liquid transitions will be advantageous. Simultaneously, enhancing the long-term stability of azobenzene energy storage is a key area for future research. Schematic diagram of molecular solar thermal energy storage

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• heat storage (>300 J/g) makes these compounds suitable for molecular solar thermal energy storage (MOST) [47]. Diazocines Diazocines are bridged azobenzenes (Figure 9). The added strain renders the E-isomer metastable, favouring the more stable Z-isomer. In the planar E-azobenzene, the nπ* transition

Azobenzene protonation as a tool for temperature sensing

• Antti Siiskonen,
• Sami Vesamäki and
• Arri Priimagi

Beilstein J. Org. Chem. 2025, 21, 1528–1534, doi:10.3762/bjoc.21.115

• emerged as staple building blocks in smart materials, from light-responsive norbornadienes in molecular solar thermal energy storage [2] to pH-sensitive spiropyrans in cell imaging [3], and redox-active viologens in memory junctions [4]. Among the different molecular switches azobenzenes stand out due to

Novel route to enhance the thermo-optical performance of bicyclic diene photoswitches for solar thermal batteries

• Akanksha Ashok Sangolkar,
• Rama Krishna Kadiyam and
• Ravinder Pawar

Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93

• molecular solar thermal energy storage. Therefore, the feasibility of the thermally reversible photoswitching in the studied BBD-based systems has also been assessed. Initially, the relative energy profiles for the conversion of the photoproducts to the dienes and undesired thermal degradation products were

• present work, (d) schematic representation of the photoswitching mechanism in the studied BBD-based photoswitches for molecular solar thermal energy storage applications. Energy storage capacities and barrier for back conversion of the photoproduct to the diene in the gas phase. (a) Storage energy, (b

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• usually gives similar or improved yields and eliminates the shortcomings in scalability. For the applications of ABs as molecular materials often larger amounts are required, for example, as active compounds in molecular solar thermal energy storage (MOST) systems. Therefore, we utilized the set-up for