Cation-induced ring-opening and oxidation reaction of photoreluctant spirooxazine–quinolizinium conjugates

• Phil M. Pithan,
• Sören Steup and
• Heiko Ihmels

Beilstein J. Org. Chem. 2020, 16, 904–916, doi:10.3762/bjoc.16.82

• discussed in the literature whether metal cations are coordinated in a monodentate fashion to the phenolate oxygen atom or rather in a bidentate fashion both to the phenolate oxygen and the imine nitrogen atoms of the open merocyanine form [25][28]. Furthermore, density functional theory (DFT) calculations

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

• Liliia Moshniaha,
• Marika Żyła-Karwowska,
• Joanna Cybińska,
• Piotr J. Chmielewski,
• Ludovic Favereau and
• Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

• using NMR spectroscopy and DFT calculations [33]. In particular, the unprecedented double α-oxygenation of bipyrroles was shown to occur through stepwise acetoxylation, which we found to compete with α–α oligomerization. These new bipyrrole boomerangs exhibited enhanced fluorescence with Φfl values of

• DFT calculations (Figure 1 and Supporting Information File 1). The length of the linker (n) in cNDAnX and cNMInX controls the in- and out-of-plane geometry of the chromophore. The observed changes can be expressed in terms of two parameters: α, the angle between the monopyrrole axis and the N–N vector

• cNMI3H were configurationally most stable, showing no loss of their optical activity over the course of several hours in solution. Their CD spectra could be satisfactorily correlated with the TD-DFT data obtained for the cNMI3H enantiomers (Supporting Information File 1, Figures S5 and S22). Circularly

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• -membered rings on the peropyrene core, the electronic structures and the frontier orbitals of the peropyrene derivative 6 without pentagons and of compound 1 are compared by DFT calculations at the B3LYP/6-311++G(d,p) level. As shown in Figure 4, the LUMO and HOMO of 6 are both delocalized over the

• -diphenylpyrene is the key step. The single crystal X-ray diffraction analysis revealed a twisted structure of 1 due to the steric hindrance at the bay positions. From the bond length analysis and DFT calculations, CP-PAH 1 consists of the aromatic peropyrene core with two slightly antiaromatic peri-fused five

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• an appropriate electrophile led to C–C bond formation, ultimately delivering chiral tertiary alcohols. Mechanistic studies and DFT calculations showed that an in situ-formed borylcopper(I) species is responsible for the 1,2-addition (Scheme 73) [136]. C,O-Diboration of ketones 464 was explored using

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes

• Zeguo Fang,
• Nawaf Al-Maharik,
• Peer Kirsch,
• Matthias Bremer,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65

• difluorocarbene addition to alpha-fluorostyrenes [13]. This used the extraordinary useful method for the generation of difluorocarbene from the Ruppert–Prakash (TMSCF3) reagent [14]. DFT analysis suggests the lowest energy conformer of aryl α,β,β-trifluorocyclopropane 7 orients the C–F bond perpendicular to the

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• fluorescence at 576 nm with a quantum yield of ΦF = 0.86 at 298 K (Figure 3). Both peaks are slightly red-shifted relative to those of intact terrylene (λabs = 560 nm and λem = 571 nm with ΦF = 0.82 in toluene). We employed density functional theory (DFT) and time-dependent (TD)-DFT calculations, both of them

• distributions is negligible because of the existence of node at 2,5,10,13-positions. The longest band of TB4 at 563 nm comprises the transition from equally destabilized HOMO (−4.29 eV) to LUMO (−1.99 eV) (oscillator strength, f = 0.86). The transition energies and oscillator strengths simulated by TD-DFT

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• , density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d) level of theory. The a2-symmetry of the HOMOs and b2-symmetry of the LUMOs of each, the α- and β-ethynyl-substituted BODIPYs are almost identical to those of the unsubstituted compound 1a (Figure S24, Supporting Information

• -dependent (TD) DFT methods. As a result, the excited-state structure of 6a exhibits a remarkably bent distortion of the core with a plane angle of 16.1°, whereas the structure of 4a remains coplanar (Figure S25, Supporting Information File 1). The corresponding energy gap between the HOMO and LUMO of 6a is

• , and DFT calculations. Supporting Information File 167: Crystallographic information file of compound 3a. Supporting Information File 168: Crystallographic information file of compound 6b. Acknowledgements We thank Dr. T. Ono at Kyushu University for the help of absolute photoluminescence quantum

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• hexaborylated HBC 1. The structure of thus-obtained 1 was confirmed by X-ray crystallography, and the electronic effects of the boryl groups were investigated through optoelectronic measurements and density functional theory (DFT) calculations. Results and Discussion We have examined the conditions for C–H

• from the singlet excited state were determined (kr = 2.0 × 106 s−1; knr = 7.9 × 107 s−1). The frontier molecular orbitals of 1 calculated by DFT calculations at the B3LYP/6-31G(d) level of theory are shown in Figure 4b. Owing to the highly symmetrical structure of 1, both its HOMO and HOMO−1 as well as

• present method. The analyzed structure from X-ray crystallography confirmed the regioselective C–H borylations at the least sterically hindered C–H bonds of HBC. Optoelectronic measurements of 1 revealed bathochromic shifts of the absorption bands compared with unsubstituted HBC. DFT calculations also

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• compounds 25–27 were calculated using DFT computational methods with discrete solute–solvent hydrogen bond interactions [66] (see optimized structures in Supporting Information File 1). Geometry optimizations were calculated at the DFT (B3PW91) level, using the 6-31G(d) basis set. The predicted 1H chemical

• factor of 1.43 [11]. Theoretical calculations Calculations for the photodegradation of carbamates The structures, properties and the basic photochemistry of compounds 11 and 12 was studied using the density functional theory (DFT) method [86][87][88][89] and the functional B3PW91 along with the 6-31 G(d

• ) Optimized structures of compounds 25–27 with the ab initio DFT computational methods, 4) DNA binding studies; 5) UV absorption spectra of all amidoxime, ethanone oxime and aldoxime carbamates; 6) Gel electrophoresis pictures of all amidoxime, ethanone oxime and aldoxime carbamate; 7) UV absorption spectra

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• in moderate to good yields (28–85%) with remarkable regio- (>95%) and enantioselectivities (91–95% ee) [39]. Interestingly, DFT calculations supported the crucial role of the imidazole moiety towards the 1,4-addition (vs 1,6 or 1,8) [39]. Thanks to the efficient post-transformation of the

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• this F···H interaction. The single crystal X-ray structure and the DFT-optimized structure showed that the fluorinated phenyl ring favors the orientation with the fluorine atom closer to H5 than H3. The X-ray structure also showed the existence of the intermolecular C–F···H–C interaction. Keywords

• : DFT; F···H hydrogen bond; fluorinated phenylcoumarin; Pechmann reaction; through-space coupling; Introduction Coumarins constitute one of the big classes of naturally occurring compounds. The first coumarin was isolated from the tonka bean (Dipteryx odorata) in 1820 and, to date, more than 1300

• aromatic triazole foldmers [37]. In their study, using crystallographic and DFT data, they concluded that their folded conformers are held by C–F···H–C hydrogen bonds. To further these studies, we have synthesized a fluorine-containing phenylcoumarin in order to study the fluorine-hydrogen bond. The

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

• Narasimhamurthy Rajeev,
• Toreshettahally R. Swaroop,
• Ahmad I. Alrawashdeh,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Seegehalli M. Anil,
• Kuppalli R. Kiran,
• Chandra,
• Paris E. Georghiou,
• Kanchugarakoppal S. Rangappa and
• Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

• theory (DFT) analysis is also presented in this article. Results and Discussion Synthesis At the onset of our study, the reaction between O-benzyl S-methyl dithiocarbonate (1a) and benzyl isocyanide was conducted in the presence of sodium hydride in DMF. The product, obtained in 85% yield after 10 min

• their O-benzyl N-thiocarbamates. The structure of one of the carbamothioates, 4c, was confirmed by a single crystal X-ray diffraction study (Figure 2 as well as Tables S1 and S2, Supporting Information File 1, CCDC reference number: 1831389) [33]. A DFT modeling study was then conducted at the B3LYP/6

• of the final products were detected in the NMR spectra, and a representative DFT computational analysis conducted with 4c (this compound also yielded a crystal structure) was in agreement with the ratio of the two rotamers that were observed in the corresponding NMR spectra. A mechanism was proposed

[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• control experiments and DFT calculations. Keywords: Brønsted and Lewis acids; DFT; mechanistic studies; rearrangement; stereochemistry; sulfur atom migration; Introduction Among all organic reactions, rearrangements are an exciting class of transformations where unusual or even unexpected products can

• dissociation are ca. 34.6 kcal/mol for the secondary alcohol 8, ca. 23.3 kcal/mol for the mesylate 60, and ca. 25.0 kcal/mol for the tertiary alcohol 20, as estimated by DFT calculations. The value for mesylate roughly fitted the range according to which the reaction may proceed at room temperature. For

• activation by AlCl3 impossible, which prevented the rearrangement. To gain detailed insights into the possible reaction mechanism, DFT calculations were performed on model β-hydroxyalkylphosphine sulfide 20, possessing two ethyl groups at the β-carbon atom. First, the Brønsted acid-catalyzed rearrangement

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• understand the 1,2,3-triazole based XB donors, model 1,2,3-triazole A, 1,2,3-triazolium B, 1,2,3-triazolylidene complex C-CuI and diiodotriazolium D were calculated by DFT calculations (Figure 9). The calculation results show that σ holes in diiodotriazolium D are mainly located in the elongation of two C–I

• bonds. The DFT calculation also shows that σ hole of in diiodotriazolium D and 1,2,3-triazolium B are comparable, and much larger than the 1,2,3-triazole A and 1,2,3-triazolylidene complex C-CuI due to positive charge effect. Conclusion In summary, we synthesized 4,5-diiodo-1,3-dimesityl-1,2,3

• the former shows a boat conformation and the latter forms a rectangle conformation. Triazolium salts form a linear polymer with polyiodide. 2-BF4 forms co-crystals with 4,4'-bipyridine via halogen bonding. DFT calculation results show that the σ holes of 4,5-diiodo-1,2,3-triazolium is similar to the σ

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• ions were fixed throughout the reaction progress. The entire cage system was treated using the above-mentioned DFT method. In order to find the TS structures, complete TS optimizations using the keywords "QST2", "QST3", and “Modredundant” were performed. A main limitation of the current cluster

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

• David Martínez-López,
• Amirhossein Babalhavaeji,
• Diego Sampedro and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

• of intramolecular H-bond formation, we wished to retain at least one methoxy group. To reduce the rate of thermal reversion, only derivatives with substituents in all four ortho-positions were considered. Time-dependent density functional theory (TD-DFT) calculations were used to predict the

• absorption wavelengths of possible derivatives. Based on these considerations, we carried out the synthesis and photochemical characterization of compounds 4 and 5. Results and Discussion Computational chemistry Calculations were performed using density functional theory (DFT) methods (B3LYP/6-31+G**) to

• optimize geometry, and TD-DFT with a Solvation Model based on Density (SMD) to calculate absorption wavelength maxima. These computational methods have been used successfully with related compounds [16][17]. The relative stability of different conformations of the molecule was calculated, i.e., with the

Why do thioureas and squaramides slow down the Ireland–Claisen rearrangement?

• Dominika Krištofíková,
• Juraj Filo,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2019, 15, 2948–2957, doi:10.3762/bjoc.15.290

• rearrangements. Furthermore, these organocatalysts slowed down the Ireland–Claisen rearrangement in comparison to an uncatalyzed reaction. The catalyst-free reaction proceeded well in green solvents or without any solvent. DFT calculations showed that the activation barriers are higher for reactions involving

• hydrogen-donating organocatalysts and kinetic experiments suggest that the catalysts bind stronger to the starting silyl ketene acetals than to transition structures thus leading to inefficient rearrangement reactions. Keywords: DFT calculations; green solvents; H-bonding catalysts; Ireland–Claisen

• , which agrees well with the DFT calculated values. These kinetic measurements support the notion that H-bonding catalysts bind stronger to starting silyl ketene acetals and thus prevent it from undergoing Ireland–Claisen rearrangement. For more details, see Supporting Information File 1. Conclusion

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• of NMR and MS spectroscopic data. The NMR assignment of 1 was assisted by DFT-based theoretical chemical shift calculation. Compound 2 showed antibacterial activity against multidrug resistant Salmonella enterica ser. Typhi with a MIC of 125 µg/mL while 1 was not active. Keywords: aromatic

• General information Conformational search was performed with MacroModel version 12.1 in the Maestro 11.7 software package [32][33]. All DFT-based calculations were performed with the Gaussian 16 Rev B.01 program [34]. A part of these computations were conducted using a Fujitsu PRIMERGY CX400 multi-node

• tensor of the most stable 4 conformers within 3.5 kcal/mol and σ0 is the shielding tensor of TMS calculated at the same level of theory with σx. The NMR shifts of structure b was similarly calculated using 50 structures as the OPLS3e-minimized structures and 4 structures as the DFT-optimized structures

Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

• Daniel R. Sutherland,
• Nidhi Sharma,
• Georgina M. Rosair,
• Ifor D. W. Samuel,
• Ai-Lan Lee and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285

• carbazoles with respect to the bridging benzene of ca. 44° in both 3 and 4 (Figure 2). Theoretical properties Density functional theory (DFT) calculations were performed in the gas phase to assess the electronic structures of 2–5 (see Supporting Information File 1 for details). The S1 and T1 excited states

• were calculated from the optimized ground-state structure using the Tamm Dancoff approximation (TDA) to time-dependent density functional theory (TD-DFT) [30][31]. In all derivatives, the LUMO is mainly localized on the strongly electron-accepting BQ moiety (Figure 3). The HOMO is mainly located on the

• ) and differential pulse voltammograms (DPVs) are shown in Figure 4 and the data are summarized in Table 1. Upon scanning to negative voltage, all four compounds exhibited two highly reversible reduction waves, a typical behavior of the BQ moiety in aprotic solvents [32]. Based on DFT calculations and a

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• supramolecular coordination complexes consisting of a Pd2L4 stoichiometry. As shown by NMR, CD and X-ray studies, as well as DFT calculations, these complexes form cage-like structures by chiral self-sorting. Photochromic ligands derived from first generation molecular motors enable light-driven interconversion

• enantiomeric cages in which the Pd–Pd axis of each cage is located at the 4-fold rotation axis. This means that the cage structure is made up with exclusively (R,R) or (S,S) enantiomer of the ligand and that the elementary cell is built from the racemic pair of cages. DFT calculations were performed to gain

• different cage structures. Interestingly, the cage structures with Pd2L4 constitution were shown to be homochiral, forming single diastereomers as evident from NMR, CD and X-ray analysis, supported by DFT calculations. Additionally, the cage structures were able to bind OTs− inside their cavity. Although

A combinatorial approach to improving the performance of azoarene photoswitches

• Joaquin Calbo,
• Aditya R. Thawani,
• Rosina S. L. Gibson,
• Andrew J. P. White and
• Matthew J. Fuchter

Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266

• performance: o-F [13][14], o-Cl [8][29][30], o-OMe [10][29][31], or o-Pyr [32]. For the sake of comparison, both mono- and di-ortho-substitutions were considered. Theoretical half-lives (t1/2) were calculated within the density functional theory (DFT) framework, according to the protocol reported in our prior

• photoswitching. Table 2 summarizes the theoretical excitation energy separation (in nm) between the characteristic n–π* and π–π* transitions in the ortho-substituted arylazopyrazoles under study. Theoretical TD-DFT calculations indicate that the family of ortho-substituted 4pzH-X presents well-separated n–π

• directly impacts the Z–E photoconversion efficiency, and thus lower PSSs of 77, 85 and 73% are recorded for 4pzMe-F2, 4pzMe-Cl2 and 4pzMe-OMe2, respectively, versus >98% for 4pzMe. Similarly, 4pzH-F2 possesses a lower PSS versus 4pzH (42% versus 70%). While inaccuracies in the DFT calculations may explain

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• emission solvatochromism. Also a donor-substituted α-pyrone shows pronounced aggregation-induced emission enhancement. Keywords: cyclocondensation; DFT calculations; fluorescence; heterocycles; 1H-pyridines; α-pyrones; Introduction A high sensitivity and precise tuneability of fluorescence colors are

• photophysical studies (absorption and emission spectroscopy) and the studies on the electronic structure were accompanied by TD-DFT calculations for assigning the dominant longest-wavelength absorption bands. Results and Discussion Synthesis and tentative mechanism Recently, we reported a straightforward access

• especially for the 6-positioned phenyl ring with 27° in the X-ray structure and 38° from calculation (for comparison to the DFT calculated ground state structure of 1H-pyridine 5a, see chapter 12.3 in Supporting Information File 1). This is probably due to packing constraints from the involvement of the 6

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

• Sarah L. Skraba-Joiner,
• Carter J. Holt and
• Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

• . DFT computations with inclusion of implicit solvation support a complex network of phenyl and biphenyl shifts, with barriers to rearrangement in the range of 10–21 kcal/mol. Consistent with experiments, the lowest energy arenium ion located on this surface is due to protonation of m,p'-quaterphenyl

• facile acid-catalyzed interconversion, as well as the fact that m-terphenyl (2) is favored at equilibrium (observed ratio 1:2:3 is <1:69:31) and used theory to explain this product selectivity [25]. This preference is consistent with formation of the most stable arenium ion intermediate, as shown by DFT

• potential energy surface. Protonation of a terminal phenyl group can also lead to terphenyl migration but this process is structurally degenerate and was not explored by computations. Both phenyl and biphenyl rearrangement pathways were studied by DFT methods, with inclusion of implicit solvation by the

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• -soluble and selective bioprobe for plasma membrane imaging. The new compound was efficiently synthesized in a two-step procedure with good yields. The photophysical properties were evaluated and the dye proved to have an excellent photostability in several solvents. DFT calculations were found in

• density functional theory (TD-DFT). In practice, when applying DFT calculations, there is no “universal” exchange correlation functional (XCF), thus the performance of different XCFs in simulating the absorption spectra of BTD-4APTEG had to be assessed. We aimed at describing the maxima absorption peak

• agreed well with the experimental data obtained for the newly developed dye. DFT calculations were also employed to forecast the lipophilic character of the dye utilizing several XCFs. Experimentally, lipophilicity can be measured by means of the logarithm of the n-octanol/water partition coefficient

Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers

• Anniina Kiesilä,
• Jani O. Moilanen,
• Anneli Kruve,
• Christoph A. Schalley,
• Perdita Barran and
• Elina Kalenius

Beilstein J. Org. Chem. 2019, 15, 2486–2492, doi:10.3762/bjoc.15.241

• and studied by multiple gas-phase techniques, ESI-QTOF-MS, IRMPD, and DT-IMMS experiments, as well as DFT calculations. The comparison of classical resorcinarenes with pyridinearenes by MS and NMR experiments reveals clear differences in their host–guest chemistry and implies that cation encapsulation

• in pyridine[4]arene is an anion-driven process. Keywords: cation binding; DFT calculations; ion mobility mass spectrometry; macrocycles; pyridinearenes; resorcinarenes; Introduction Resorcinarenes and their derivatives are known for the molecular recognition properties of their self-assembled

• could not be verified and the anions were assumed to interact with the pyridinearene cavity. Inclusion complexes of anions within pyridinearene dimers were also theoretically studied by DFT calculations, but using a truncated pyridinearene dimer model [8]. However, previous studies have also shown that