Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• with poly(ethersulfone) [143]. Highly reactive gaseous species may also generate radicals on polymer surfaces. For example, atomic oxygen radical anions emitted from 12CaO⋅7Al2O3 crystals [144] were used to modify PVC and polystyrene [145][146]. Plasma is also a powerful gas-phase tool for polymer

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

• dyads adopts a puckered geometry (i.e., nonplanar geometry). This is known for the PTZ moiety [69][70]. We also optimized the geometry of the dyads at the S1 and T1 states (Tables S1 and S2 in Supporting Information File 1). In gas phase or nonpolar solvents, the dihedral angles between the NI and the

• ) NI-PTZ-F, (b) NI-PTZ-Ph, (c) NI-PTZ-CH3, (d) NI-PTZ-OCH3, (e) NI-PTZ-C5, (f) NI-PTZ-F-O, (g) NI-PTZ-Ph-O, and (h) NI-PTZ-C5-O. Calculated at the B3LYP/6-31G(d) level of theory using Gaussian 09. Spin density surfaces of the dyads in the T1 state (gas phase) of (a) NI-PTZ-F, (b) NI-PTZ-Ph, (c) NI-PTZ

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• [36] via the polyphosphoric acid (PPA) catalysed cyclisation of 2,2'-diaminobibenzyl (20) at elevated temperatures (Scheme 3) [37][38]. 1.3 Catalytic dehydrogenation An early synthesis of 5H-dibenzo[b,f]azepine (1a) involved the gas phase dehydrogenation of 10,11-dihydro-5H-dibenzo[b,f]azepine (2a) to

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• been studied, the stoichiometries, the units used for concentrations, and the solvent. The basis for the stoichiometry should be reported for a binding reaction. If substances such as CO2, N2, and NH3 are reactants, one must specify if these substances are in solution or in the gas phase and give the

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• significantly lower but more easily implemented level of theory (PBE0 functional [41], 6-31+G(d) basis set, gas phase), followed by calculation of the 31P NMR chemical shifts with the same PBE0 functional with the still-modest 6-311G(2d,2p) basis set. While the calculated fit to experimental values was

• complicated by water solvation, as well as ionization or aggregation of the phosphoric acid in water, and calculation as a gas-phase chemical shift is also unreasonable [51]. Because of these issues, other studies have used PH3 as an alternative theoretical reference standard [18][19], despite the fact that

• actual use of this compound requires a fairly extraordinary experimental setup [52][53]. An additional issue with PH3 involves the choice of using the gas-phase or liquid-phase experimental chemical shifts, which differ dramatically: the universally used value for the gas-phase chemical shift is −266.1

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• °, respectively, has been observed, although a propeller-like gauche-gauche-gauche configuration of alkyl(aryl)thio groups has been observed for trithiophosphites even in the solid state [7] or in the gas phase [8][9][10]. Triferrocenyl trithiophosphite has nine axes of internal rotation: three P–S bonds, three C

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• ) NI-PTZ2, (d) NI-Ph-PTZ, and (e) NI-PhMe2-PTZ; the green and orange sheets show the planes of the donor and the receptor. Kohn–Sham frontier molecular orbitals (CAM-B3LYP/6-31G(d) in gas phase) involved in S1, T1, and T2 of NI-N-PTZ, NI-PTZ, NI-PTZ-O, NI-PTZ2, NI-Ph-PTZ, and NI-PhMe2-PTZ, based on the

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• cage nitrogen atoms) and/or rotamers (restricted rotation around amide C–N bonds), which is well-known for amides and carbamates (Figure 4a). The activation barriers for the rotation across amide C–N bonds in 4a and 4c estimated by DFT (18.4 and 19.4 kcal/mol, respectively, ωB97XD/Def2TZVP, gas phase

• complexes is thermodynamically favored in the gas phase by 1–4 kcal/mol (ΔG°) showing rather weak bond character in these structures. Indeed, the guest molecules are liberated upon drying of the obtained crystal solvates in a vacuum with gentle heating. Interestingly, a higher preference in coordination of

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• spectrometry (HRMS) (Figures S1–S24 in Supporting Information File 1), and melting point analysis. We modelled the electron density distribution in DiKTa-OBuIm and DiKTa-DPA-OBuIm using density functional theory (DFT) calculations in the ground state, at the PBE0/6-31G(d,p) level of theory in the gas phase

• ) the MR-TADF emitter DiKTa and selected derivatives, and (c) the ionic emitters in this work. (a) HOMO and LUMO electron density distribution and orbital energies of DiKTa-OMe and DiKTa-DPA-OMe calculated at the PBE0/6-31G(d,p) level of theory in the gas phase, isovalue = 0.02; (b) difference density

• plots and energies for the two lowest-lying singlet and triplet excited states for DiKTa-OMe and DiKTa-DPA-OMe calculated at SCS-CC2/cc-pVDZ in the gas phase (isovalue = 0.001). The blue color represents an area of decreased electron density, and yellow represents an increased electron density between

Dienophilic reactivity of 2-phosphaindolizines: a conceptual DFT investigation

• Nosheen Beig,
• Aarti Peswani and
• Raj Kumar Bansal

Beilstein J. Org. Chem. 2022, 18, 1217–1224, doi:10.3762/bjoc.18.127

• varying the values is followed. In view of this, we carried out all calculations in the gas phase only. Thus all geometries were optimized in the gas phase at the B3LYP/6-31+G(d) level of theory. Frequency calculations were done at the same level to determine zero-point correction and to characterize

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• proposed based on computational results and the main product is formed favorably following the PES via the lowest ΔG# pathway in both the gas-phase and an ethanol solvent model. DFT calculations showed that kinetic selectivity is more significant than thermodynamic selectivity for forming main products

• ’ by 1.3 kcal·mol−1 in the gas phase or by 0.4 kcal·mol−1 in the ethanol solvent model. The transformation of 4a into 4a’ occurs with a small potential barrier of 0.5 kcal·mol−1 (in the gas phase) or 1.0 kcal·mol−1 (in ethanol). This process goes through TS1 by H displacement at the O–H bond of the O–H

• to form product 10ab and isomers from 4a/4a’ in the gas phase. The ΔG, ΔG# values for each stage in the PES at the gas phase are collected in Table 2. The 4a and 4a’ tautomers react with CH3NH2 to yield products, as detailed in Figure 4. All three C (C−O) sites in 4a, 4a’ are possible for interaction

Understanding the competing pathways leading to hydropyrene and isoelisabethatriene

• Shani Zev,
• Marion Ringel,
• Ronja Driller,
• Bernhard Loll,
• Thomas Brück and
• Dan T. Major

Beilstein J. Org. Chem. 2022, 18, 972–978, doi:10.3762/bjoc.18.97

• two byproducts, isoelisabethatrienes A and B. Fascinatingly, a single active site mutation (M75L) diverts the product distribution towards isoelisabethatrienes A and B. In the current work, we study the competing pathways leading to these products using quantum chemical calculations in the gas phase

• on the mechanistic details of the HP and IE pathways using computational methods in the gas phase. Gas-phase studies have been crucial in understanding terpene chemistry [10][11][12][13][14][15][16][17][18][19][20][21][22]. This work sheds light on the thermodynamic and kinetic parameters of the

• ). We studied the inherent chemistry of the reaction leading to HP and IE using gas-phase calculations. This provided the free energy of distinct carbocation intermediates and transition states along the proposed reaction path leading to products in the gas phase. The gas phase is a natural choice as a

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• highly delocalised bipolaron states [69]. Computation of structure Since all attempts to grow crystals of EtH-T-DI-DTT failed, we predicted the structure with a density functional theory (DFT) gas-phase optimisation using the B3LYP[70][71]/6-311g(d,p) [72] level of theory, using both the Gaussian09 [73

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• “Mixed torsional/Low-mode sampling” in the MMFF force field. The searches were implemented in the gas phase with a 15 kJ/mol energy window limit and 10,000 maximum number of steps to explore all potential conformers. The Polak–Ribiere conjugate gradient (PRCG) method was utilized to minimize conformers

• with 10,000 iterations and a 0.001 kJ (mol Å)−1 convergence threshold on the root mean quare (RMS) gradient. All the conformers of 1–3 within 3 kJ/mol of each global minimum were subjected to geometry optimization using the Gaussian 16 package (Gaussian Inc.) in the gas phase at B3LYP/6-31G(d) level

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• catalysts under harsher experimental conditions with T higher than 100 °C in the gas phase [61]. More importantly, the product distribution observed is rather unusual if compared to many other heterogeneous catalytic systems known in the literature for leading to higher selectivity for camphene [62][63][64

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• equilibrium between A and B using semiempirical calculations (AM1 and PM3) and DFT (B3LYP/6-31G(d)) in the gas phase and water, where it was observed that in the gas phase B is the most stable, while in water A is formed, which is in agreement with the experimental results reported in the literature. There

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• , endergonic by 18.8 kcal·mol−1 (gas phase) and 20.1 kcal·mol−1 (1,4-dioxane with PCM); almost thrice the Gibbs free energy for the same reaction with DABCO as a HAT abstractor. The barrierless character is supported by NEB-TS calculations (vide infra) (Supporting Information File 1, Figure S16). Both these

• the reaction step with 1 in gas phase and in 1,4-dioxane. The HAT reaction step catalyzed with quinuclidine is exergonic (−8.0 kcal·mol−1), while the reaction step involving DABCO is endergonic (+6.8 kcal·mol−1), in agreement with what would be expected from BDE and BDFE analyses. The solvent effect

• leads to only minor differences in the thermodynamics of the reaction and do not change the qualitative picture. The HAT step carried out with DABCO presents a kinetic barrier of 16.9 kcal·mol−1 in the gas phase while the quinuclidine-catalyzed reaction is predicted to be barrierless as shown in Figure

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• DICzTRZ were determined by a combination of NMR spectroscopy, mass spectrometry, and IR spectroscopy. Theoretical calculations Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations in the gas phase at the PBE0/6-31G(d,p) level reveal the potential of DICzTRZ as a TADF material. The

• the gas phase predict that the T1 state is CT in nature while the lowest-lying triplet states with LE character are T3 and T4 (T3 and T4 are at 2.73 eV and 2.75 eV, respectively, while T1 is at 2.64 eV, see Supporting Information File 1, Table S1 and Figure S3). The character of the different

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• TURBOMOLE program (version 7.4.1) [43]. Geometries were pre-optimized using the PBE [44] functional, the def2-SVPD [45][46] basis set and D3 [47] dispersion correction. All structures were then re-optimized using the hybrid functional B3LYP [48][49][50][51] D3 with the def2-TZVPPD basis set. For gas-phase

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Chiral isothiourea-catalyzed kinetic resolution of 4-hydroxy[2.2]paracyclophane

• David Weinzierl and
• Mario Waser

Beilstein J. Org. Chem. 2021, 17, 800–804, doi:10.3762/bjoc.17.68

• ) via gas phase pyrolysis of para-xylene in 1949 [5]. Over the years, these compounds established themselves as a unique class of “bent and battered” [6] strained molecules with remarkable chemical and physical properties [1][2][3][4][7][8][9]. Besides their potential applications in material and

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• preferred gas-phase reaction. The ecology of marine bacteria in their interaction with algae is particularly interesting in which the bacteria can promote the algal growth, but can also kill their host [10][11]. For both processes, the phytohormone indole-3-acetic acid is used as a messenger molecule [10

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

• -substituent (i.e., H, CH3, or CF3) would have a poor impact. Gas phase calculations by Tsuno et al. provided evidence for the significantly increased resonance stabilization contribution in 14f↔14f’ (r = 1.4) relative to the t-cumyl cation 57 (r = 1.0) [69]. α-(Trifluoromethyl)heteroarylcarbenium ions The

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• : Hexafluoropropylene oxide (HFPO, 41) is an effective and cheap reagent for the difluorocyclopropanation of simple alkyl- and aryl-substituted alkenes [52]. It undergoes decomposition to form difluorocarbene (Scheme 16) at temperatures above 170 °C either under autoclave conditions or by gas-phase co-pyrolysis [53

Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation

• Dongyang Chen and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 210–223, doi:10.3762/bjoc.17.21

• , respectively. The compounds 2CzCF3, 2CzSCF3, and 2CzSF5, from Type I molecules, show significant promise as deep blue TADF emitters, possessing high calculated singlet energies in the gas phase (3.62 eV, 3.66 eV, and 3.51 eV, respectively) and small, ΔESTs, of 0.17 eV, 0.22 eV, and 0.07 eV, respectively. For

• calculated in gas phase in this work), which was reported as deep blue emitter with λEL = 418 nm and CIE coordinate of (0.15, 0.05) when doped in DPEPO [21]. DFT calculations for 5CzOCF3, 5CzSCF3, and 5CzSF5 predicted dense populations of excited states between T1 and S1, which should assist in rISC process

• [28][29]. Results and Discussion We employed density functional theory (DFT) and TD-DFT calculations to predict the photophysical properties of these emitters in order to assess their potential as TADF emitters for OLEDs. All ground-state calculations were performed using PBE0/6-31G(d,p) in the gas