Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• organometallics guests, albeit less common, are also observed. These form a variety of structures from supramolecular second-sphere coordination adducts to pseudorotaxanes [35][36]. With highly charged metal ions, electrostatic interactions and first-sphere coordination bonds are dominant, while second-sphere

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• devices or therapeutics [1], drug delivery [2], supramolecular sensing [3], purification [4], and separation [5][6]. The interactions in supramolecular assemblies are driven by well-known hydrogen-bonding, hydrophobic interactions, electrostatic interactions and π–π stacking [7][8]. The supramolecular

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 and ion-pairing are shown. Single crystal structure of complexed Cs2SO4 with 18-crown-6 and tripodal receptor L (CCDC: 2411573). One sulfate anion is encapsulated inside the hexaurea cavity through 12 × N–H···O hydrogen bonds. One Cs+ cation is co-stabilized by electrostatic interactions

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• contributions to binding is likely due to stronger electrostatic interactions between the guest and the sulfate ionic groups. For both C1 and M1, the Me6HDA and Me6PXDA are the strongest binding guests whereas the cyclohexane and adamantane-based guests with a larger cross-sectional area bind 10–100-fold more

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• pyrroleninic core of the porphyrin is diprotonated, which induces the formation of supramolecular aggregates, stabilized by ion-pair contacts (electrostatic interactions) between the cationic porphyrin centers and anionic sulfonate groups of the periphery (Figure 10a). In 2018, the group reported heterogeneous

• secondary amine 57. They have hypothesized that the organocatalytic activity of the aggregates is based on two types of interactions, i.e., electrostatic interactions of α,β-unsaturated iminium cations derived from cinnamaldehyde and the cyclic secondary amine with anionic sulfonate groups and π–π

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

• them suitable media for regulating the rotaxane structure. Concurrently, for CD-based rotaxane systems, employing a transition metal or inducing electrostatic interactions encounters more limitations owing to the synthetic shortcoming of integrating high-polar moieties in their dumbbell framework that

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

• Stiliyana Pereva,
• Stefan Dobrev,
• Tsveta Sarafska,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

• sides, unlike the internal cavity, are hydrophilic, decorated with primary (narrow rim) and secondary (wider rim) hydroxy groups. Van der Waals (vdW) and hydrophobic interactions have been identified as the main driving forces for CDs inclusion complex formation [2][3][4]. Electrostatic interactions and

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

• interactions responsible, in part, for the solid-state ordering [52]. Individual pyrans stack on top of one another in a manner consistent with electrostatic interactions with halogens facing H3, H4, and H5 (Figure 4a). As such, some intermolecular H···X bond distances and angles for compound 13–15 are listed

Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

• the potential energy and interatomic interactions within a molecular system. The CHARMM force field includes parameters for various types of atoms, bonds, angles, dihedrals and non-bonded interactions, encompassing van der Waals forces and electrostatic interactions. CHARMM19 (united atom), CHARMM22

• bonds, smoothed van der Waals interactions, and electrostatic interactions. The SLICK scoring function, tailored for carbohydrates, enhances the accuracy of predicting binding modes and free binding energies. Compared to other programs such as AutoDock and FlexX (see below), BALLDock/SLICK demonstrates

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• nN→σ*CF electron delocalization, is particularly important in modulating the energetics of the α-fluoro isomers and imparts a strong conformational bias. In contrast, the fluorine gauche effect assumes a secondary role, as it is overshadowed by steric and electrostatic interactions, referred to as

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• molecules because the chain portion of PASE turns upward. Therefore, the stabilization energy of hydrogen-bond formation is greater in conformation 2 than in conformation 1. To improve the stability of conformation 2, hydration effects by electrostatic interactions between PASE and the solvent are also

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• /electrostatic interactions [18][19][20]. Replacing oxygen atoms with other elements, such as nitrogen, sulfur, etc., alters the crown ethers' affinity toward cations, extending their role as macrocyclic ligands to transition metals [21]. One can say that in many aspects, porphyrins and crown ethers are

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

• , finally, the structure with the lowest energy, with the functional PBE0-D4/mTZVPP/CPCM. The Hartree–Fock plus London dispersion (HFLD) method was used for the study of non-covalent interactions (NCI). The calculations lead to the conclusion that a reduction in electrostatic interactions and an increase in

• the amine nitrogen of the guest molecule. In addition to hydrogen bonding, other interactions such as π–π stacking and electrostatic interactions also play a role in the complexation process. These interactions can be modulated by changing the pH, solvent, and temperature of the solution. The binding

• studied complexes, categorized as electrostatic, exchangeable, dispersion, and charge-transfer interactions. From the data presented in Table 2, it is evident that electrostatic interactions in the form of hydrogen bonds primarily contribute to the formation of R[4]:sec-amine complexes with a 1:1

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• TBTQ-C6 in water at pH 5.3 due to the more pronounced steric hindrance and the stronger charge repulsion on their complex surface [29][30]. Moreover, we propose that TBTQ-C6/CS-TPE supra-amphiphiles connected by electrostatic interactions self-assemble in water layer-by-layer with the outer surface

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

• both long-range electrostatic interactions and the interactions of the ions with each other and with the solvent. The inverse calculation to obtain K from K′ can also be performed by using regression. The scientific principles behind these calculations and transformed thermodynamic quantities are

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• phenyl-ring rotations thus enhancing the AIE property. The resulting m-TPEWP5G self-assembled worm-like nanosystem acts as an ideal donor and loading EsY as acceptor on the surface of the worm-like nanostructure, leads to the generation of a nanorod assembly via electrostatic interactions. The final AIE

• -like nanostructure (diameter = 748 nm). After the loading of EsY into m-TPEWP5G, the worm-like structure changed into a nanorod (diameter = 652 nm) assembly via electrostatic interactions. In comparison, the diameter and length of the m-TPEWP5G assembly were slightly higher than that of m-TPEWP5G-EsY

• Supporting Information File 1). When 1 equiv of EsY was added into the m-TPEWP5G solution, the resonance signals of EsY were shifted to upfield regions, which was caused by steric effects and electrostatic interactions between the quaternary ammonium groups containing m-TPEWP5 and the negatively charged EsY

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• 2 weeks. However, this could result in a sustained release over longer time periods which would require further investigation. Doxorubicin release from heparin-containing cryogel microcarriers was investigated by Newland et al. [100]. Highly sulphated heparin was used to exploit electrostatic

• interactions between anionic sulphate groups and the primary amine group present in doxorubicin which confers a positive charge under physiological conditions. This interaction was confirmed by in silico modelling. While the carriers did not show any cytotoxicity, cell viability was reduced in the presence of

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• thermoresponsive behavior of polymers is governed by oriented polymer–polymer interactions, such as hydrogen bonding or electrostatic interactions. As a function of temperature, these attractive interactions are formed and contribute to phase separation (T < UCST) or are increasingly destabilized and allow

• , UCST type behavior is generally governed either by strong hydrogen bonding or by attractive electrostatic interactions [51][52][55]. UCST resulting from strong hydrogen bonding interactions. Increasing interest is focussed on nonionic polymers in water, whose UCST behavior is based on hydrogen bonding

• under physiologically relevant pH and salt conditions via the hydrophilicity of the co-monomers and their molar ratio [52][55][279]. UCST resulting from attractive electrostatic interactions. The thermoresponsive behavior of zwitterionic polymers, in contrast to the previously mentioned UCST type

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• better hybridization properties than LNA-thymidine; however, only modification 22 gave significant increases in Tm relative to modification 19 used as control. This finding was ascribed to both the extended π-conjugation of the alkynyl-functionalized nucleobase and stabilizing electrostatic interactions

Antiviral therapy in shrimp through plant virus VLP containing VP28 dsRNA against WSSV

• Santiago Ramos-Carreño,
• Ivone Giffard-Mena,
• Jose N. Zamudio-Ocadiz,
• Alfredo Nuñez-Rivera,
• Ricardo Valencia-Yañez,
• Jaime Ruiz-Garcia,
• Maria Teresa Viana and
• Ruben D. Cadena-Nava

Beilstein J. Org. Chem. 2021, 17, 1360–1373, doi:10.3762/bjoc.17.95

• formation and CP-dsRNAi complexes (Figure 2A, images a and b). The Gaussian fit size distribution of the spherical procapsids gave an average diameter of 21.2 nm and corresponded to capsids with triangulation number T = 2. The sample’s dialysis at pH 7.2 favors the electrostatic interactions between CCMV CP

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

• extensive documentation of the electrostatic interactions within the molecules and the observed conformational biases [145

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• not rely on specific binding motifs. Here, electrostatic self-assembly was shown to yield a variety of supramolecular nanostructures [4][26][27][28][29][30][31][32][33]. We have built the nanoscale assemblies from polyelectrolytes and multiply oppositely charged molecules based on electrostatic

• interactions and secondary interactions such as π–π stacking [34][35][36][37][38][39][40]. The size and shape could be tuned through the free energy and the enthalpy/entropy interplay in the assembly process, which again are encoded in the molecular building block structure [31][37]. Supramolecular structures

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• selectively obtained over the conventional 9,10:9',10'-cyclodimers by the supramolecular photocyclodimerization of 2-anthracenecarboxylate (AC) with the aid of β-CD-functionalized cationic derivatives as chiral catalysts (Figure 7) [25]. Due to the electrostatic interactions between cationic CD and anionic AC

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• an electrostatic interaction between two molecules at 10 Å is around 1 kJ/mol, which is much higher than any other force at such a distance [47]. Long-range electrostatic interactions are affected by the net charges of the protein, i.e., proteins with a different net charge are electrostatically

• , it has been shown that the CCMV capsid formation is driven by electrostatic interactions governed by the pH value and the ionic strength [93]. Here, the positive N terminus of the assembly unit interacts with the negatively charged scaffold and drives the self-assembly process [94]. The advent of

Chiral anion recognition using calix[4]arene-based ureido receptors in a 1,3-alternate conformation

• Tereza Horáčková,
• Jan Budka,
• Vaclav Eigner,
• Wen-Sheng Chung,
• Petra Cuřínová and
• Pavel Lhoták

Beilstein J. Org. Chem. 2020, 16, 2999–3007, doi:10.3762/bjoc.16.249

• anions is becoming more and more significant [12][13][14]. There are many strategies aiming at anion recognition in the literature. Most of the receptors, however, rely on electrostatic interactions. These systems are represented by positively charged molecules, such as quaternary N-, S-, and P