The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• determine their interaction with other molecules in their environment [103]. It is evident that the dipole moment, a physical parameter which is macroscopic in nature, can be evaluated in order to characterize solvent polarity. The value calculated for methyl laurate is shown in Table S1 in Supporting

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• of the C–O bond “opens” the molecule, generating the corresponding merocyanine (Figure 2). The reverse photocyclization can occur upon exposure to visible light. Remarkably, the two isomers differ in their chemical and physical properties such as polarity, molecular volume, dipole moment

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

• parallel excited state because of the larger dipole moment [121]. To enrich the population of the antiparallel (and thus increasing the quantum yield of cyclisation), bulky substituents on the 2,2’ positions of benzothiophene were added [122], also the antiparallel conformation could be fixed by

Thermodynamics and polarity-driven properties of fluorinated cyclopropanes

• Matheus P. Freitas

Beilstein J. Org. Chem. 2025, 21, 1742–1747, doi:10.3762/bjoc.21.137

• delocalization interactions. Among the compounds shown in Figure 1, 1.2.3-c.c. is the most polar, with a calculated dipole moment of 4.17 D. Polarity is a key molecular property, as it influences solubility, lipophilicity, and various material characteristics. For example, liquid crystals used in LCD devices

• rely on specific properties such as dielectric anisotropy, where the molecular dipole moment aligns parallel to the molecule’s long axis [19]. Compound 1.2.3-c.c. exhibits a "Janus"-face-like structure, characterized by a positively charged region on one side and a negatively charged region on the

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• excited states due to the twisted structures by the π-stacked [2.2]paracyclophane moieties. The CPL behaviors of (Sp)-6 and (Sp)-7 were investigated by TD-DFT calculations; namely, the electric transition dipole moment (μ), magnetic transition dipole moment (m), and the angle (θ) between μ and m in the S1

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• , resulting in a significant dipole moment of 1.08 D [18]. Due to its unique non-alternant topology, azulene exhibits a smaller energy gap compared to that of isomeric naphthalene and unusual emission from the S2 state (anti-Kasha’s emission), as a consequence of its non-mirror related highest occupied

• exceptionally narrow optical gaps. A striking example is the perylene isomer 172, which displays absorption extending to 1720 nm and an electrochemical gap of just 1.07 V [104]. The presence of two parallel azulene moieties in this structure results in an enhanced dipole moment (1.97 D) compared to pristine

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

• Zhihua Liu,
• Ya-Zhi Chen,
• Ji Wang,
• Qingling Nie,
• Wei Zhao and
• Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

• ion-dipole interaction of the Li+ cation and carbonyl groups also contribute to the extraction. The negative electrostatic potential (δ−) of O=C is attributed to a high dipole moment of the urea unit (mono(urea): 3.95 D, bis(urea): 7.55 D) [34][35][36], which has been demonstrated to be capable of

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• (I, Figure 2). This has several implications. For example, if the C–C(F) bond rotates, the orientation of the terminal C–F bond dipole changes, and this can alter the overall dipole moment of the molecule. Indoles 1–3 illustrate this point (Figure 2) [9]. The non-fluorinated indole 1 has an unvarying

• molecular dipole moment of 1.90 D. In contrast, the monofluorinated analogue 2 can access three different staggered rotamers 2a–c about the C–C(F) bond; all three of these rotamers have similar energies, but their molecular dipole moments vary considerably depending on whether the C–F dipole is aligned with

• , conformations in which the two C–F bonds are aligned gauche will be favoured in water due to their high molecular dipole moment. A final layer of complexity is afforded by the stereochemistry of the 1,2-difluoroalkane motif: the various conformational factors described above will aggregate differently depending

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• Molecular photoswitches have been studied for a long time because their physicochemical properties such as refractive index [1][2], dipole moment [3][4], conductivity [5][6], magnetism [7][8], and fluorescence [9][10][11] can be spatiotemporally modulated by light without physical contact. Therefore

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• fluorine atoms, inserted in the aromatic rings, which considerably modifies the dipole moment of the corresponding fluorinated aromatic rings with respect to their hydrogenated homologs, thus influencing their behavior, binding affinities, and optoelectronic properties. These interactions already represent

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• S4, Supporting Information File 1) and the Kawski–Chamma–Viallet plots [59][60] (Figure 4, see Supporting Information File 1 for details) showed good linearity. This also indicated that the excited-state dipole moment of the molecules was much higher than that in the ground state. This phenomenon was

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• arrangement for compound 15 and the crystal packing of compound 13 and 14 can be found in the Supporting Information File 1. The halogens are on the same side of the pyran ring, thus increasing the overall molecular dipole moment (see Supporting Information File 1). This allows intermolecular C–X···H–C

Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression

• Tabea Bartsch,
• Stephan Lütz and
• Katrin Rosenthal

Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192

• -hexane due to the low solubility of n-hexane in water, a limited interfacial area, and evaporation in the headspace. There is no clear trend for the influence of the polarity or log P of the added solvents. Among the water-miscible additives, methanol, whose dipole moment is relatively close to that of

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

• charge transport. The copolymers, Qx2, Qx3, and Qx4, formed by combining QxCN with different aryl groups showed down-shifting of lowest unoccupied molecular orbital (LUMO) levels and enhanced electron injection and transport. Furthermore, the dipole moment introduced by the CN groups improved charge

• importance of specific substitutions. While Qx44b demonstrated favorable properties such as a superior dipole moment, narrow bandgap, and red-shifted absorption, the reduced charge transfer rate presented a challenge. This analysis emphasizes the need for a delicate balance between desirable electronic

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

• interactions between the solvent and dipole moment of the chromophore (Figure 3b). The Lippert–Mataga plot showed two linear slopes indicating the presence of two different excited states in the molecule. In the high-polarity region, the excited-state dipole moment (μe) was 19.04 D, which was close to that of

• a typical CT molecule 4-(N,N-dimethylamino)benzonitrile (μe = 23 D) [55], suggesting a CT state-dominated character in high-polarity solvents. Besides, in the low-polarity region, the μe value was 5.49 D, which is slightly higher than the ground-state dipole moment (μg = 1.30 D) estimated using

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• and acceptor molecules (N···F and N···H bonding when using the acceptor Y6), as well as an induced dipole moment in the molecule for increased work function tuning of the cathode. The use of benzyl and pentafluorobenzyl substituents was to evaluate the impact of H vs F on the electrochemical

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

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• material, which induced a nonzero dipole moment in the crystal lattice. As a consequence, a strain-induced charge potential of at least 1.23 eV was produced on the surface of the material, leading to the conversion of mechanical energy into chemical energy. Mechanistically, the ZnO and BaTiO3 participated

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

• only the geometry is altered from the planar (E)-AB to its twisted (Z)-AB form, but also its properties change (e.g., dipole moment and polarity) [13][14]. Furthermore, the (Z)-AB can be reversibly switched back by visible light or thermally [15]. To synthesize ABs a variety of reactions can be chosen

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• between the dipole moment of the host and the excited state dipole moment of the TADF molecule [19]. The activation energy for the TADF process of the D–A compound 1 is as low as 15 meV. Nevertheless, the TADF efficiency of the D–A compound in CBP is much lower when compared to that in Zeonex® and its D–A

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

• ) of the device. A compound will emit light perpendicular to its transition dipole moment (TDM), quantified by the anisotropy factor, a. Controlling the orientation of the TDM to lie horizontally in the film (where 1 − a is the fraction of horizontally aligned TDMs) will lead to a maximized amount of

• increased spin-vibronic coupling [28][29][30][31][32][33]. The permanent dipole moment (PDM) of DICzTRZ is substantial increased to 2.1 Debye compared to that in ICzTRZ (0.3 Debye); however, both the transition dipole moment (TDM) and oscillator strength (f) are slightly smaller (TDM = 7.6 Debye and f

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• Vijayendra S. Shetti Department of Chemistry, National Institute of Technology Karnataka, Surathkal 575025, India 10.3762/bjoc.17.139 Abstract Azulene is a non-alternant, aromatic hydrocarbon with many exciting characteristics such as having a dipole moment, bright color, stimuli responsiveness

• ). The striking feature of azulene is its permanent dipole moment (1.08 D) and blue color unlike its colorless isomer naphthalene [4]. Azulene possesses an unequal distribution of electron density between its highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• polarity difference. In fact, derivative 4f shows the highest dipole moment of 4.276 D as compared to 4a (0.698 D). As shown in Table 5, the ionization potential (IP) and electron affinity (EA) of tetrahydroacridines are almost identical. In addition, EHOMO and ELUMO do not change notably and the

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• the n-hexane and water solutions, the calculated CT distances are 1.5 and 2.0 Å, respectively. The change in the dipole moment, caused by the excitation, is greater in water being 6.1 D vs 4.9 D in n-hexane. Moreover, the calculated τ index is much greater in the case of the water solution (0.520 Å in