Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• ) derivatives. Push–pull substitution on the 2 and 3 position as well as introduction of oxygen or nitrogen at position 7 of the NBD scaffold have led to the development of a new family of photoswitches. We studied the potential conversion of norbornadiene to quadricyclane (QC) isomers. As main investigation

• catalytic back-conversion studies. Keywords: heterocycles; molecular solar thermal systems; norbornadiene; photochemistry; quadricyclane; Introduction In recent decades, the demand for renewable energy has increased tremendously [1]. A promising alternative to fossil fuels is the utilization of so-called

• of azaborines [14][15] to the corresponding Dewar isomer and the norbornadiene/quadricyclane (NBD/QC) couple [16][17][18], Notably, the NBD/QC couple exhibits characteristics superior to those of the other mentioned photoswitches, including the highest energy storage density [19]. For MOST systems

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• Gutenberg University Mainz, Duesbergweg 10–14, 55128 Mainz, Germany 10.3762/bjoc.20.254 Abstract The photochromic norbornadiene/quadricyclane pair is a promising system for molecular solar thermal (MOST) energy storage, with which solar energy may be converted, stored, and released as heat in one integral

• up to 8 h at room temperature. Furthermore, the norbornadienes were transformed quantitatively into their quadricyclane photoproducts by irradiation with green light (520 nm) in the presence of a photosensitizer. Keywords: light energy conversion; photochemistry; photochromism; quadricyclanes

• ], azobenzenes [16][17][18][19], dihydroazulenes [20][21], or azaborines [22][23]. However, the most prominent feasible MOST system is the [2 + 2] photocycloaddition–cycloreversion cycle between norbornadiene (1a) and quadricyclane (2a), which has several advantageous properties (Scheme 1) [8][14][24]. In

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

• /vinylheptafulvene, azobenzenes, tetracarbonyl(fulvalene)diruthenium complexes, norbornadiene/quadricyclane (NBD/QC), anthracenes, etc. exhibit a few promising properties for MOST applications [10][12][13]. However, these photoswitching couples still lack one or more important properties required in MOST systems and

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• Robin Schulte Heiko Ihmels Department of Chemistry and Biology, University of Siegen, and Center of Micro- and Nanochemistry and (Bio)Technology (Cμ); Adolf-Reichwein-Str. 2, 57068 Siegen, Germany 10.3762/bjoc.18.41 Abstract The photochromic norbornadiene/quadricyclane system is among the most

• quadricyclane upon irradiation, whereas the back reaction can be accomplished by thermal treatment. Keywords: molecular solar thermal system; Pd-mediated catalysis; photochemistry; photoswitches; quadricyclanes; Introduction Norbornadiene (1a, bicyclo[2.2.1]heptadiene) is a photochromic compound that has

• recently gained considerable attention because of its ability to store light-energy by the photo-induced intramolecular [2 + 2] cycloaddition to the metastable quadricyclane [1][2][3][4][5][6][7]. The latter may be transformed back to the starting norbornadiene in an exothermic process upon heating or

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• of quadricyclane 218 with thiocarbonyl derivatives 219. With carbon disulfide, mono- and biscycloadducts 221 and 222 were formed depending on concentration, temperature, and pressure conditions [69] (Scheme 43). In the same year, Kanaoka and co-workers reported the intermolecular photo [2 + 2

• 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietane-generated bis(trifluoromethyl)thioacetone with various olefins in nucleophilic solvents DMF or DMSO. Previously, the reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietane (363) and quadricyclane (218) was carried out in diglyme in the presence of CsF

• as catalyst, affording the thietane 364 in 74% yield. However, a 60% yield of the thietane 364 was obtained without the catalyst and solvent. The reaction of sulfur, KF, perfluorobut-2-ene (365) and quadricyclane (218) in DMF at 130 °C generated 4-trifluoromethyl-4-pentafluoroethyl-3-thiatricyclo

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

• Roland Löw,
• Talina Rusch,
• Tobias Moje,
• Fynn Röhricht,
• Olaf M. Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

• ; quadricyclane; self-assembled monolayers; TATA platform; thermal isomerization; TOTA platform; Introduction Recently, we discovered that the thermochemically forbidden cis–trans isomerization of azobenzenes can be efficiently catalysed by a very peculiar mechanism on bulk gold [1]. In heterogeneous catalysis

• -catalysed” [2 + 2] cycloreversion on bulk gold of quadricyclane 1b to norbornadiene 1a (Figure 1). The cycloreversion of most quadricyclane systems proceeds smoothly in solution upon irradiation in the presence of triplet sensitizers [7]. If 1b is adsorbed on a gold surface the bulk gold could take the role

• complete conjugation path across the double bond of norbornadiene to the metal. Additionally, it is known that electron-withdrawing groups in 2 or 3 position change the triplet energy hypersurface in such a way that a triplet excited quadricyclane 1b decays into the ground state of the norbornadiene 1a [9

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• sulfides, cyclic dienes and styrenes [1][2], fluoride anion-catalyzed reactions of compound 1 with vinyl ethers [1][3][4], vinyl sulfides [3], ketene dimethylacetal [5], styrenes [6][7], cyclic dienes [8] and quadricyclane [9]. At this point, no data for the reaction of HFTA or HFTA dimer with vinylamines