Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• benzyl moiety on the substrate resulted in tandem Friedel–Crafts reactions to form the 1-aryltetraline products. These compounds share a close analogy to the cyclolignan natural products. Experimental observations and a DFT study support the involvement of an aldehyde intermediate during the Friedel

• alternative mechanism, we envisionned a possible interconversion of 7 and 7’ through a [1,5]-sigmatropic rearrangement resulting in a hydrogen and cation shift towards 7’ (Scheme 4). To test this hypothesis, this rearrangement was computed at the DFT level. A cyclic transition state (TS) was found between

• number 2301977. Supporting Information File 41: Experimental procedures, compound characterizations, crystallographic data, DFT calculation, and spectra. Supporting Information File 42: Crystallographic information file of compound 6. Funding This work was supporting by the French Agence Nationale de la

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• . The absolute configurations of the axially chiral TCBD and DCNQ derivatives were ascertained by a comparative analysis of the experimental CD spectra against the spectra derived from time-dependent density functional theory (TD-DFT) calculations. The axial chirality was stabilized by the steric

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

• Laura Abella,
• Gerard Novell-Leruth,
• Josep M. Ricart,
• Josep M. Poblet and
• Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

• (CIIAE), FUNDECYT-PCTEx, Polytechnic School of Caceres Building, Office CIIAE-C7, Av. Universidad s/n, 10003 Cáceres, Spain 10.3762/bjoc.20.10 Abstract Fullerene dimerization inside a peapod is analyzed at DFT level by characterizing the stationary points and deriving the energy profile of the initial

• metadynamics simulations provide hints on structures for the initial steps of the irreversible phase 2 where bond formation and breaking lead to important structural reorganizations within the coalescence process. Keywords: DFT; dimerization; fullerene; molecular dynamics; peapods; Introduction Transmission

• pressures and high temperatures [13][14][15]. We aim to shed light in these reaction mechanisms and energy profiles by using complementary methodologies as standard density functional theory (DFT) calculations and first-principles Car–Parrinello molecular dynamics (CPMD) simulations. Firstly, we have

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• structure (DFT) of PA-CH3. b) Structures of PA-OCH3, PA-OH, and PA-Im. 1H NMR spectra (500 MHz, rt, 0.5 mM and 1.0 mM based on PA-CH3 and PA-OCH3, respectively, TMS in CDCl3 as external standard) of a) PA-CH3 in CD3OD, b) (PA-CH3)n in D2O, c) PA-OCH3 in CD3OD, and d) (PA-OCH3)n in D2O. DLS charts (rt, H2O

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• for (Cyc-DMBI)2 is consistent with DFT estimates of bond dissociation energies for these two dimers (ΔUdiss = 163 and 210 kJ mol−1, respectively [18][44]) and with their reactivity towards TIPS-pentacene [18][39]. Impact of photoexcitation The absorptivities, ε, of (N-DMBI)2 and (Cyc-DMBI)2 at 365 nm

• weak shoulder at ca. 400 nm (ε400 ≈ 150 M−1 cm−1), whereas (Cyc-DMBI)2 exhibits only a strong feature with a maximum at 327 nm (εmax = 13000 M−1 cm−1). TD-DFT calculations (M06/6-31G(d,p), isolated molecules) qualitatively reproduce the different behavior of the two dimers: for (Cyc-DMBI)2 the S0→S1

• amplitude at 654 nm decays with a 1 ps lifetime. The isosbestic point in Figure 4a is consistent with a clean transformation such as monomer formation. The corresponding monomeric radicals are calculated using TD-DFT (M06/6-31G(d,p)) (Figure 4e) to have absorptions at similar energies to those seen in the

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• ) values [26] of the carbon atoms (θσπ-90˚) of the La@C2v-C82 anion were calculated using density functional theory (DFT) [27][28][29][30][31][32][33]. As shown in Table 1 and Figure 6, the C1, C2, and C3 atoms have large negative charge densities (C1: −0.1498, C2: −0.1828, C3: −0.1126), and C1 and C2

• were calculated using the Gaussian 03 program with DFT at the B3LYP/3-21G for C and H [33], and the LanL2DZ basis set and effective core potential (ECP) for La [29][32]. La@C2v-C82(CH2C6H4CH3) (2a): vis–NIR (CS2): λmax = 572, 741, 1304 nm; MALDI–TOF MS (m/z): [MH]+ calcd for LaC90H9, 1228.98; found

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• . The high thermal stability is profitable for the preparation of stable and durable OLED devices. Computational chemistry Ground-state geometry optimization of DMB-TT-TPA (8) was performed using density functional theory (DFT) calculations with the Gaussian 16 software at the B3LYP/6-31G (d,p) level

• and TT units, the LUMO was found to be delocalized through the dimesitylboron and TT ring, the results being in line with the experimental values of our previous study [23]. On the basis of the optimized ground-state geometry, time-dependent DFT (TD-DFT) calculations were conducted in THF to

• computation data, 1H and 13C NMR spectra. Acknowledgements The authors thank Dilara Gunturkun for DFT calculations, Istanbul Technical University (ITU). Funding The authors thank THD-2023-44904, PTA-2023-44900, TGA-2023-44077, TDA-2022-43696 numbered ITU BAP Projects and 122Z568 numbered TUBITAK 1001 Project

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• esters 8, 9 without the requirements of phosphine or other photocatalysts (Scheme 5). Through the use of density functional theory (DFT) calculations, they elucidated the mechanism behind this process. It was revealed that the formation of a photoactive EDA complex, which subsequently generated alkyl

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• charge transport behavior. DFT calculations assisted the interpretation of electron and hole migration mechanism using the frontier orbital energies and the conjugation within the π-system. Results and Discussion The syntheses of 1 and 2 were previously published in [25] and [26], respectively. 1 is a

• transport [37][38]. Therefore, to better understand the charge mobility of compounds 1 and 2, we obtained their ground state geometry using DFT within the B3LYP/def2-TZVP(-f) level of theory (Figure 8a). To reduce computational efforts, isopropyl moieties were used instead of the large aliphatic

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• trifluoroacetaldehyde hydrazones. Jasiński et al. demonstrated that the CF3 group offered an appropriate electronic balance through experimental spectral analysis and computational DFT methods, and the hydrazones could be readily used to provide convenient access to azo tautomers under the acidic conditions [43]. The C

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• the 1H,13C-HSQC and 1H,13C-HMBС spectra, as well as by comparing the experimental carbon chemical shifts in DMSO-d6 with those calculated for 6 by the GIAO method at the PBE1PBE/6-311+G(2d,p) level of theory using the DFT B3LYP/6-311++G(d,p) optimized geometries (DMSO solution) and applying a multi

• the PBE1PBE/6-311+G(2d,p) level of theory using the DFT B3LYP/6-311++G(d,p) optimized geometries (DMSO solution) and applying a multi-standard approach [44]. The calculated shifts of sp2-atoms C-7a, C-4, C-6, C-3, and C-3a in (Z)-8 and the s-cis-conformer (with respect to the C4–N bond) of 9 were

• 156.6, 152.1, 151,9, 128.3, 105.6 ppm and 160.9, 158.9, 157.4, 123.3, 98.4 ppm, respectively. The corresponding experimental shifts (155.0, 151.8, 149.9, 128.4, 105.4 ppm) were in good agreement with the structure 8. It is noteworthy that the DFT B3LYP/6-311++G(d,p) calculations using the PCM solvation

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• compounds are stable at physiological-like conditions, especially the methyl-derived one, which qualifies them for further toxicological and activity studies, such as those involving trivalent metal ions sequestering in the context of neurodegenerative diseases. Keywords: DFT calculations; N-acylhydrazones

• experimental absorptions were performed not only with the aid of DFT calculations, but also checked by comparing them to the vibrations of the respective carbonyl and hydrazide precursors. Although the phenol-related ν(O–H) bands could not be accurately identified due to overlapping with the water stretching

• –H) and δoop(O–H) modes were assigned, respectively, at 1376 and 720 cm−1 for hdz-CH3, and at 1359 and 747 cm−1 for hdz-NO2. Interestingly, DFT showed that, while these vibrations are “clean” in hdz-CH3, they were coupled with NBA ring movements in hdz-NO2. Therefore, the IR results confirm the

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• chemistry offers a cost-effective and time-efficient means of screening and selecting promising candidates for experimental exploration. Bhattacharya et al. employed density functional theory (DFT) approach to explore structural modulation for tuning the optoelectronic properties of Qx13. Their designed

• quinone unit on quinoxaline to achieve donor–acceptor interactions and desirable electronic properties. The compounds exhibited absorption, emission, electrochemical, and thermal properties suitable for n-type materials. Theoretical properties were also investigated using time-dependent DFT. The HOMO and

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• MALDI-TOF-MS techniques. To examine the electronic properties of D–A TPECNz, density functional theory (DFT) calculations at the B3LYP level of theory with the 6-31G(d,p) basis set were performed. It has been previously reported that the twist angle of the D–A segment has a significant role in

• . To further figure out excited-state properties of TPECNz, the natural transition orbitals (NTOs) of singlet (S) and triplet (T) excited states were executed based on time-dependent (TD)-DFT calculations at the CAM-B3LYP/6-31G(d) level of theory. As shown in Figure 1b, the hole and particle of TPECNz

• points were measured using a Krüss KSP1N melting point meter and are uncorrected. Quantum chemical calculations were executed using the Gaussian 16 package [67]. Density functional theory (DFT) calculations at the B3LYP level of theory with the 6-31G(d,p) basis set were performed to realize the ground

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• previously reported for the Y = cyclohexyl, R = R' = H derivative 1e2 (1.640(4) Å) [14], despite DFT calculations indicating that the former dimer is considerably more weakly bonded [8][14] and kinetic evidence for the “cleavage-first” mechanism occurring in doping reactions using 1b2 but not 1e2 (see below

• according to: where ΔGdiss(12) is the free-energy change for dissociation of 12 to 1• (dissociation energetics are not estimated in the present work, but have been estimated using DFT calculations for 1b–e2 in previous works [8][14] and, in favorable cases, can be experimentally estimated using electron

• their Y = cyclohexyl counterparts, 1e+/1e• and 1h+/1h•, respectively. These differences are also similar to those previously seen in the comparison of Y = metallocenyl systems 1c+/1c• and 1d+/1d• with 1e+/1e• (and in the DFT-calculated ionization energies of 1c–e•) [14][50] and are perhaps surprising

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• ′, and 24 conformers for 3. The geometry of each conformer was optimized using DFT calculations at the B3LYP/6-31G(d) level of theory [20][21] with the conductor-like polarizable continuum model (CPCM) solvent model (MeOH) and Gibbs free energy was calculated subsequent frequency calculations. Time

• -dependent (TD)-DFT calculations at the B3LYP/6-31+G(d,p) level with CPCM solvent model (MeOH) [22] were performed for the optimized conformers. The resulting ECD spectra calculated for each conformer were averaged using Boltzmann populations evaluated at 300 K from Gibbs free energy calculated from the

• GIAO and TD-DFT calculations. b) Comparison of experimental ECD spectra of 1 (gray solid line) and 6 (black dotted line) with the Boltzmann-weighted spectra computed for 1′ (red dashed line). c) Comparison of the experimental ECD spectra of 2 (gray solid line) and 7 (black dotted line) with the

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• exchange and dispersion interactions in CHCl3 in relation to DMSO are the driving forces behind the placement of sec-amine molecules into the R[4]A cavity and the formation of “in” type complexes. Keywords: complexes; DFT calculations; hydrogen bond; resorcin[4]arene; supramolecular chemistry

• atoms, presenting a challenging and time-consuming task for geometry optimization calculations and screening via DFT methods. Recent advancements have introduced fast semi-empirical DFT methods such as xTB [15], which enable their use in preliminary screening for molecular dynamics or searching for

• reactive sites (aISS), for example, in the formation of supramolecular complexes [16]. The particularly fast GFN-xTB methods work well in geometry optimization, which is the most time-consuming step of the DFT calculation. There have also been developments in DFT methods concerning the energy distribution

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• possibility of through-space interactions with prenyl side chains using DFT calculations. Our calculations show that (i) the unstable secondary carbocation is stabilized by the cation–π interaction from prenyl side chains, thereby lowering the activation energy, (ii) the four-membered ring formation is

• completed through bridging from the exomethylene group, and (iii) the annulation from the exomethylene group proceeds in a barrier-free manner. Keywords: biosynthesis; carbocation; cation–π interaction; DFT; terpene; Introduction Terpene/terpenoids are most abundant natural products in nature, more than

• , computational chemistry including DFT [5][6][7][8][9], QM/MM [10][11][12][13][14][15][16] and QM/MM MD [14][15][16][17] calculations have been used for the biosynthetic studies of terpene/terpenoids [18]. Terpene-forming reactions, which involve various types of carbocation species stabilized by

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• first thiolation and intramolecular cyclization of propargyl azides the removal of N2 and a proton. Subsequently, monothiolated perroles were subjected to the second thiolation process to prepare 3,4-bisthiolated pyrroles. Cyclic voltammetry and DFT calculations revealed that the 3,4-bisthiolated

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• , the O-protonated forms ArC(=OH+)CH=CHCCl3, which are then cyclized into the target CCl3-indanones. These cations have been studied experimentally by means of NMR spectroscopy in TfOH and theoretically by DFT calculations. Under the same superacidic conditions in TfOH, CCl3-hydroxy ketones (1-aryl

• =CHC(=O)Me] with arenes in Brønsted superacid TfOH (triflic acid, CF3SO3H) furnishes 3-methyl-1-trichloromethylindenes (Scheme 1a) [11]. Based on NMR analysis in TfOH and theoretical DFT calculations, it has been found that the reaction proceeds through an intermediate formation of the O-protonated

• , we initiated this study on transformations of 1-aryl-4,4,4-trichlorobut-2-en-1-ones under superelectrophilic activation conditions (Scheme 1b). The main goals of this work were the investigation of the protonation of CCl3-enones (1-aryl-4,4,4-trichlorobut-2-en-1-ones) by NMR spectroscopy and DFT

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• compounds, including diaryl- and dialkyl ketones and prochiral ketones, respectively (Scheme 36) [50]. Riant, Leyssens and co-workers investigated the mechanism of the hydrosilylation reaction of ketones using DFT, in situ FTIR, NMR, and kinetic methods [51][52]. The catalytic characteristics of sterically

• mentioned earlier, we recently reported the results of the theoretical investigation of different classes of NHCs and their NHC–Cu(I) complexes at the DFT level [21]. It was shown that in the NHC–Cu(I) complexes, the negative charge density is located mainly in the CuX region. The molecular electrostatic

• [Cu2(μBr)2(t-BuImCH2pyCH2L)]2 species 138 acting similar to the NHCs. A very low loading of these complexes was sufficient to catalyze the azide–alkyne cycloaddition. A theoretical investigation at the DFT level confirmed the participation of the dinuclear species [(CuBr)2(μ-t-BuImCH2pyCH2NEt2)] 139

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• experience a very weak solvatochromic effect with increasing solvent polarity from cyclohexane to dichloromethane. This indicates only minor change of the dipole moment upon vertical excitation from S0 (6.4 D) to S1 (7.2 D) excited states according to the TD-DFT theoretical calculations (Table S2, Supporting

• π-conjugation. The twisted structure of the 4BGIPN ensures that the donor groups accommodate the highest occupied molecular orbital (HOMO) while the acceptor 4,6-dicyanobenzene moiety contains the lowest unoccupied molecular orbital (LUMO) and is supported by the TD-DFT calculations. A comparison of

• ). Computational results Computations were performed using density functional theory (DFT) for the ground state and time-dependent DFT (TD-DFT) with Tamm–Dancoff approximation [24][25] for the excited states calculations, using the global hybrid MN15 functional by Truhlar [26] in combination with the def2-TZVP

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• the reaction mechanism supported by DFT calculations and concluded that FeF2 plays an important redox role in assisting the cleavage of oxidants and the oxidation of carbon radicals to cationic intermediates of oxygen. CDC reactions between C(sp3)–H/C(sp)–H bonds catalyzed by iron have been reported

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• were studied by steady state UV–vis absorption spectroscopy, transient photoluminescence spectroscopy, nanosecond/femtosecond transient absorption spectroscopy, electrochemistry, as well as DFT/TDDFT computations. We observed experimental evidence for the spin–vibronic coupling effect in the TADF

• coupling, i.e., the 3LE mediate 3CS → 1CS rISC in TADF [27]. The photochemical properties of each compound in different solvents are summarized in Table 5. Computational investigations The optimized ground state geometry of the dyads at the DFT-B3LYP/6-31G (d) level of theory determined with Gaussian 09

• pulsed laser). The wavelength is tunable in the range of 410–2500 nm. Calculation study The geometries of the compounds in their ground state were optimized using density functional theory (DFT) with the B3LYP functional and the 6-31G(d) basis set [72]. The excited state geometries of S1 and T1 were