Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• substituents to make little contribution to the HOMO of either 1H or 12 (as shown in calculated molecular orbitals for several examples [14][50][55][59][60]) and so the dependence of these potentials on Y is likely to be due to a combination of inductive effects and perhaps steric effects on the molecular

• conformation. As expected, methoxy R' substituents lead to 1H•+/1H and 12•+/12 potentials that are more reducing than those for analogous species without these groups. 1h2 (Y = cyclohexyl, R = H, R' = MeO) is the most easily oxidized DMBI dimer that we have examined to date; however, it is a little less easily

Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

• Daniela Rodrigues Silva,
• Joyce K. Daré and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

• lipophilicity with the molecular conformation. Keywords: dipole moment; fluorinated compounds; gauche effect; herbicides; log P; Introduction Whilst in the last years the agrochemical industry has encountered a period of downturn affected by new regulations, low crop prices, biochemical resistance, among

• macroscopic observed properties, such as lipophilicity [13]. Accordingly, the main goal of this work is to investigate the relationship between lipophilicity and molecular conformation on a set of organofluorine agrochemicals. To this end, this study has been divided in two parts. First, we have analyzed the

• organic molecule, as above mentioned. Therefore, this work also seeks to assess a correlation between calculated μ values and experimental log P measures, in order to unveil the dependence of lipophilicity with molecular conformation. Results and Discussion Conformational analysis of penoxsulam Given the

Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

• Afef Mabrouki,
• Malek Fouzai,
• Armand Soldera,
• Abdelkader Kriaa and
• Ahmed Hedhli

Beilstein J. Org. Chem. 2020, 16, 149–158, doi:10.3762/bjoc.16.17

• hydrocarbonated counterparts just present a thermotropic character. The dipole moment-molecular conformation relationship was scrutinized in order to elucidate the role of the molecular conformation on the dipole moment magnitude. Since some of the studied compounds show mesomorphic properties, it is important to

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

• highly depends on the molecular conformation, significantly increasing for T-shaped structures (4pzH-X) compared to twisted arrangements (4pzMe-X), and thus leading to larger n–π* band separation for the 4pzH-X series [18]. On the other hand, the intense π–π* transition of the Z-isomer is generally found

Conformational preferences of α-fluoroketones may influence their reactivity

• Graham Pattison

Beilstein J. Org. Chem. 2017, 13, 2915–2921, doi:10.3762/bjoc.13.284

• Graham Pattison Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK 10.3762/bjoc.13.284 Abstract Fluorine has been shown in many cases to impart specific and predictable effects on molecular conformation. Here it is shown that these conformational effects may

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• experimental logD and the ‘theoretical’ logD derived from Equation 5 (MW – molecular weight in Da, logD in log m2 s−1) (Figure 6). The increase in these values indicates a ‘coil’ contribution in the molecular conformation. However, it should be kept in mind that the diffusion data describes the overall

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• the atom-numbering scheme. Displacement ellipsoids for non-hydrogen atoms are drawn at the 30% probability level. Only the major component of disordered fluorine atoms is presented. (b) Overlap of molecules 5–8 showing almost identical molecular conformation. Color code: 5 green, 6 orange, 7 purple, 8

Bifunctional organocatalysts for the asymmetric synthesis of axially chiral benzamides

• Ryota Miyaji,
• Yuuki Wada,
• Akira Matsumoto,
• Keisuke Asano and
• Seijiro Matsubara

Beilstein J. Org. Chem. 2017, 13, 1518–1523, doi:10.3762/bjoc.13.151

• . Moderate to good enantioselectivities were afforded with a range of benzamide substrates. Mechanistic investigations were also carried out. Keywords: axial chirality; benzamide; bifunctional organocatalyst; molecular conformation; multipoint recognition; Introduction Bifunctional organocatalysts have

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• , respectively. Figure 8b shows the energy minimized conformational structure of TPM-G5. Based on the observed d-spacing values and energy minimized molecular conformation of TPM-G5, a possible molecular packing arrangement in the self-assembled gel state is presented (Figure 9b). One possible arrangement is an

Sydnone C-4 heteroarylation with an indolizine ring via Chichibabin indolizine synthesis

• Florin Albota,
• Mino R. Caira,
• Constantin Draghici,
• Florea Dumitrascu and
• Denisa E. Dumitrescu

Beilstein J. Org. Chem. 2016, 12, 2503–2510, doi:10.3762/bjoc.12.245

• spectroscopy, with further supporting X-ray structural elucidation of the representative compound 9d, which displays an interesting packing feature described below. The molecular structure and numbering scheme for 9d are shown in Figure 2a. Principal torsion angles that describe the molecular conformation

Is conformation a fundamental descriptor in QSAR? A case for halogenated anesthetics

• Maria C. Guimarães,
• Mariene H. Duarte,
• Josué M. Silla and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2016, 12, 760–768, doi:10.3762/bjoc.12.76

• conformation of the compounds in a data set is usually unknown and, therefore, geometry optimization is carried out in a receptor-free environment to generate the molecular structure and, subsequently, the 3D MD´s. While molecular conformation in vacuum is governed by intramolecular interactions, the

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• planes is 2.67 (2)° which is slightly lower than the dihedral angle observed in the case of the pyridine-2-carbaldehyde 2,4-dinitrophenylhydrazone that is 3.88 (8)° [39]. The molecular conformation of the ligand is stabilized by a strong intramolecular N3–H3···O1 (2.015 (6) Å) hydrogen bond making the

Enantioselective synthesis of polyhydroxyindolizidinone and quinolizidinone derivatives from a common precursor

• Nemai Saha and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2014, 10, 3104–3110, doi:10.3762/bjoc.10.327

• = 17.4, 4.8 Hz) protons as well as strong nOe between the protons on 6-H and 9a-H, 6-H and 8-H, 8-H and 9a-H, 1-H and 2-H and 2-H and 3-H as indicated in Figure 5. These studies led us to believe [38] the molecular conformation of 23 to be 5C8. Conclusion In conclusion, we have developed an efficient

Macrocyclic bis(ureas) as ligands for anion complexation

• Claudia Kretschmer,
• Gertrud Dittmann and
• Johannes Beck

Beilstein J. Org. Chem. 2014, 10, 1834–1839, doi:10.3762/bjoc.10.193

• in good yields. The quest for the molecular conformation is challenging for both molecules. Since the bis(triazenide) congeners of 1 and 2 are planar, one can presume an analogous molecular shape for the bis(ureas). All attempts to obtain single crystals of 1 for a structure determination failed

A new synthetic access to 2-N-(glycosyl)thiosemicarbazides from 3-N-(glycosyl)oxadiazolinethiones and the regioselectivity of the glycosylation of their oxadiazolinethione precursors

• El Sayed H. El Ashry,
• El Sayed H. El Tamany,
• Mohy El Din Abdel Fattah,
• Mohamed R. E. Aly,
• Ahmed T. A. Boraei and
• Axel Duerkop

Beilstein J. Org. Chem. 2013, 9, 135–146, doi:10.3762/bjoc.9.16

• molecular conformation is stabilized by three intramolecular C–H···N hydrogen bonds, three intramolecular C–H···O hydrogen bonds, and five intermolecular C–H···O hydrogen bonds in the crystal network (Figure 1, Figure 2 and Table 1). Compound 29 (Figure 3, Figure 4 and Table 2) crystallized as a cyclic

• )–C(16)–N(2) = 2.2(4)°. The molecular conformation is stabilized by an intramolecular hydrogen bond O(4)–H(4)···O(3) and a water molecule links two molecules in the crystal lattice through an intermolecular hydrogen bond O(6)–H(6P)···S(1). Conclusion In conclusion, 2-N-(glycosyl)thiosemicarbazides of

A new family of four-ring bent-core nematic liquid crystals with highly polar transverse and end groups

• Kalpana Upadhyaya,
• Venkatesh Gude,
• Golam Mohiuddin and
• Rao V. S. Nandiraju

Beilstein J. Org. Chem. 2013, 9, 26–35, doi:10.3762/bjoc.9.4

• of the Becke (3-parameter)–Lee–Yang–Parr (B3LYP) hybrid functional and the 6-31g(d,p) basis set using the Gaussian 09 package, to obtain the information related to molecular conformation, bend angle, dipole moment, molecular polarizability, and asymmetry parameter of all the compounds 1a–1f. Full

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• favouring one type of conformation in the azocompounds. Considering the relationship between the molecular conformation and biological recognition, it is particularly interesting to design azo devices that allow control, by an external stimulus, of the configuration of the N=N double bond, and also to

The interplay of configuration and conformation in helical perylenequinones: Insights from chirality induction in liquid crystals and calculations

• Elisa Frezza,
• Silvia Pieraccini,
• Stefania Mazzini,
• Alberta Ferrarini and
• Gian Piero Spada

Beilstein J. Org. Chem. 2012, 8, 155–163, doi:10.3762/bjoc.8.16

• suitable information on the molecular conformation in solution can be obtained from NMR-NOE experiments [31]; however, these do not provide the population of each single conformer but only the overall probability of t, g+ and g− states around bonds C(13)–C(14) and C(16)-C(17). For ease of comparison, we

Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan

• Axel G. Griesbeck,
• Jörg Neudörfl and
• Alan de Kiff

Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60

• to acetonitrile or methanol, respectively. It is remarkable that under solid-state conditions the molecular conformation of 10 in the crystal lattice is synclinal with respect to the indole and the phthalimide groups as well as for the indole and the carboxy groups, indicating a ground-state

The C–F bond as a conformational tool in organic and biological chemistry

• Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

• for medicinal chemists seeking to control the molecular conformation of drugs and bioprobes. This section will show that the C–F bond is also emerging as a useful tool in the field of catalysis. Recent reports have shown that organocatalysts can be conformationally “fine-tuned” by fluorine

• moment in addition to reinforcing the molecular conformation with two F–C–C–O gauche alignments [41]. With a developing knowledge of the behaviour of multi-vicinal fluoroalkanes it has been possible to develop new liquid crystals containing several fluorine atoms, in which the fluorine atoms affect the

• molecular conformation as well as the molecular dipole moment. The difluoro compound 60 (Figure 15) can be viewed as a conceptual progression from the axially fluorinated liquid crystal 58. NMR and modelling data show that the fluoroalkyl chain of 60 adopts a zigzag conformation in which the two C–F bonds

Trifluoromethyl ethers – synthesis and properties of an unusual substituent

• Frédéric R. Leroux,
• Baptiste Manteau,
• Jean-Pierre Vors and
• Sergiy Pazenok

Beilstein J. Org. Chem. 2008, 4, No. 13, doi:10.3762/bjoc.4.13

• carbon-oxygen bond may decrease by almost one tenth of an Å (Table 6). A fluorine substituent can lead to a change in the preferred molecular conformation. For example, methoxybenzenes without ortho substituents favor a planar conformation. However, Roche researchers by searching trifluoromethoxybenzenes

Molecular recognition. 1. Crystal structures of hexaazamacrocyclic amines containing p-xylylene spacers and their adducts with acids

• Teresa Borowiak,
• Grzegorz Dutkiewicz,
• Maciej Kubicki,
• Marek Pietraszkiewicz,
• Agnieszka Gil and
• Rainer Mattes

Beilstein J. Org. Chem. 2005, 1, No. 16, doi:10.1186/1860-5397-1-16

• isolated centrosymmetric molecules. The molecular conformation together with the atom labeling scheme is shown in Figure 4. The overall conformation of the molecule is ellipsoidal with the approximate dimensions of 6.2 and 15.3 Å. All atoms of the molecule (except hydrogens) are within 2.16 Å of the mean

• height of one sheet corresponds to the height of the macrocycle, i.e. about 12 Å. The molecular conformation of 1-N-Me, atom labeling scheme indicated. Displacement parameters are drawn at 50% probability level. The unit cell of 1-N-Me, stacks of molecules are indicated. Formulas of macrocyclic amines, 1