Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• synthesis to access up to –[CH2]10– macrocycles or acyl halides to access up to –[CH2]14– macrocycles. Seventy-five receptor–anion complexes were modelled and studied with COSMO-RS, in addition to all free host molecules. In order to predict initial selectivity towards carboxylates, 1H NMR relative

• carboxylates were modelled computationally using COSMO-RS. Several observations were made from the computational structures. Intramolecular hydrogen bonds between the urea carbonyl and the carbazole NH protons were present in macrocycles MC001 and MC003, as indicated in Figure 4. The rings of these macrocycles

• -electron transducer); d) an ion-selective membrane with a plasticized PVC matrix. The inset shows a cross-section of the center of the sensor tip. Studied receptor molecules. MC001 and MC003 lowest energy conformers (COSMO-RS) showing intramolecular bonds. Color coding: white – hydrogen; green – carbon

First principle investigation of the linker length effects on the thermodynamics of divalent pseudorotaxanes

• Andreas J. Achazi,
• Doreen Mollenhauer and
• Beate Paulus

Beilstein J. Org. Chem. 2015, 11, 687–692, doi:10.3762/bjoc.11.78

• , rotational and vibrational contributions are taken into account and solvation effects including counter ions are investigated by applying the COSMO-RS method, which is based on a continuum solvation model. The calculated energies agree well with the experimentally determined ones. The shortest investigated

• ; Gibbs energy; pseudorotaxanes; solvent effects; COSMO-RS; Introduction If two or more binding sites of a molecular system are involved in the association process, the interaction energy can be significantly increased compared to the sum of the individual binding energies. This effect is called

• derived from the difference of the solvation effects of the product and the reagents, calculated with COSMO-RS [28][29]. For the COSMO-RS (BP_TZVP_C30_1301.ctd parameterization) calculation all structures have been optimized in an ideal conductor [30] and in vacuum with BP86/def-TZVP [31][32][33][34

Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines

• Andreas Gansäuer,
• Meriam Seddiqzai,
• Tobias Dahmen,
• Rebecca Sure and
• Stefan Grimme

Beilstein J. Org. Chem. 2013, 9, 1620–1629, doi:10.3762/bjoc.9.185

• -statistical corrections from energy to free energy at a given temperature and corrections for solvation free energy by the reliable (DFT-based) COSMO-RS continuum solvation model [29][30]. For recent applications of this procedure see [31][32][33]. The estimated accuracy is 1–2 kcal mol−1 for absolute free

• HOMO–SOMO energy gaps were evaluated using the TPSS-D3/TZVP orbitals. The COSMO-RS model [29][30] was used as implemented in COSMO therm [51] to obtain all solvation free energies. Single point calculations employing the default BP86 [37][38]/def-TZVP [52] level of theory were performed on the

• predictions (‘the right answer for the right reason’) can only be achieved when both effects are accounted for by, e.g., the D3 and COSMO-RS models. Extrapolated CCSD(T)/CBS via MP2/CBS calculations and estimating the basis set limit by explicitly correlated CCSD-F12(T)/cc-pVDZ-F12 yield an almost identical

The β-cyclodextrin/benzene complex and its hydrogen bonds – a theoretical study using molecular dynamics, quantum mechanics and COSMO-RS

• Jutta Erika Helga Köhler and
• Nicole Grczelschak-Mick

Beilstein J. Org. Chem. 2013, 9, 118–134, doi:10.3762/bjoc.9.15

• level the parallel and vertical positions from the starting structures converged to a structure where benzene assumes a more oblique position (−20.16 kcal mol−1 and −20.22 kcal mol−1, resp.) as was reported in the literature. The character of the COSMO-RS σ-surface of β-CD was much more hydrophobic on

• certainly no longer displayed the highly ordered hydrogen bonds of β-CD and benzene occupied many different positions inside the cavity, before it left the β-CD finally at its O2/O3 side. Keywords: AM1; benzene; COSMO-RS; cyclodextrin; hydrogen bonds; inclusion complex; molecular dynamics; quantum

• study cyclodextrin chemistry is given in [17]. The COSMO-RS solvation model [18] allows for calculations of several thermodynamic properties [19] once the polarisation charge surface of molecules has been determined by DFT calculations. With the current implementation of COSMO-RS, hydrogen-bond energies