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Search for "crystal structures" in Full Text gives 249 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

My maize and blue brick road to physical organic chemistry in materials

  • Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

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  • gelator design. We hypothesized that the Cambridge Structural Database (CSD), which contains over 700,000 organic and inorganic crystal structures, could be used to identify molecules that exhibit 1D interactions in the solid state. The rationale was that these molecules, or closely related derivatives
  • single crystals of six gelators and five nongelators. Of the six gelator crystal structures, only three had PXRD patterns that matched the gel. Within this limited data set we found 1D intermolecular interactions being present and absent amongst both gelators and nongelators, providing no clear
  • distinction based on molecular packing. Next, we performed a Hirshfeld surface area analysis to quantitatively evaluate the intermolecular interactions within the crystal structures [32]. This analysis provides information about the nature and extent of intermolecular interactions in the solid state
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Published 08 Feb 2016

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

  • Sophie Letort,
  • Sébastien Balieu,
  • William Erb,
  • Géraldine Gouhier and
  • François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

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  • from external associative complexes. UV-visible and fluorescence spectroscopy often provided useful information, while IR was rarely used. Finally, NMR and X-ray crystal structures gave more details on the inclusion mode and the interactions of the pesticide into the oligosaccharide cavity. In addition
  • formation of the inclusion complex. Thus, on the basis of these last results, the formation of an internal inclusion complex was favored by the authors. In 2013, Cruickshank reported the X-ray crystal structures of the heptakis(2,3,6-trimethyl)-β-cyclodextrin (TRIMEB)–fenthion complex (complex with 2
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Published 05 Feb 2016

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

  • Mino R. Caira,
  • Susan A. Bourne,
  • Halima Samsodien and
  • Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

Graphical Abstract
  • crystal structures containing the rocuronium ion, a well-known neuromuscular blocking agent consisting of a steroid nucleus that is highly functionalised [17], this species being encapsulated by specially designed CD derivatives [per-6-deoxy-per-6-carboxyethylsulfanyl-γ-CD and 6-perdeoxy-6-per(4
  • Crystallographic Database [16], structure solution by isomorphous replacement was not possible. Both crystal structures were therefore solved ab initio by direct methods using the program SHELXD [22]. Model development involved successive difference Fourier syntheses and iterative refinement by the full-matrix
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Published 16 Dec 2015

Smart molecules for imaging, sensing and health (SMITH)

  • Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

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  • ] (Scheme 3). Many X-ray crystal structures were acquired and they provided excellent atomic scale insight. The liquid extraction and membrane transport properties were evaluated and we demonstrated symport processes that used anion concentration gradients as energy sources to drive cation transport uphill
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Published 10 Dec 2015

Life lessons

  • Jonathan R. Nitschke

Beilstein J. Org. Chem. 2015, 11, 2350–2354, doi:10.3762/bjoc.11.256

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  • emphasize the use of simple precursors to build complex products. The preparations and crystal structures of three of these products are shown in Figure 1. Each of these products was prepared simply by mixing the precursors shown in water, and each represents a different way to arrange four metal ions in
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Published 27 Nov 2015

2-Hetaryl-1,3-tropolones based on five-membered nitrogen heterocycles: synthesis, structure and properties

  • Yury A. Sayapin,
  • Inna O. Tupaeva,
  • Alexandra A. Kolodina,
  • Eugeny A. Gusakov,
  • Vitaly N. Komissarov,
  • Igor V. Dorogan,
  • Nadezhda I. Makarova,
  • Anatoly V. Metelitsa,
  • Valery V. Tkachev,
  • Sergey M. Aldoshin and
  • Vladimir I. Minkin

Beilstein J. Org. Chem. 2015, 11, 2179–2188, doi:10.3762/bjoc.11.236

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  • -1,3-tropolones and 4,5,6,7-tetrachloro-1,3-tropolones in the reaction of methylene-active five-membered heterocycles with o-chloranil using density functional theory (DFT) quantum chemical methods. Molecular and crystal structures of three representative 2-hetaryl-1,3-tropolones have been determined
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Published 12 Nov 2015

Investigation of the role of stereoelectronic effects in the conformation of piperidones by NMR spectroscopy and X-ray diffraction

  • Cesar Garcias-Morales,
  • David Ortegón-Reyna and
  • Armando Ariza-Castolo

Beilstein J. Org. Chem. 2015, 11, 1973–1984, doi:10.3762/bjoc.11.213

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  • is absent in compounds 3–8. The solid-state conformations of the piperidones were determined by X-ray diffraction (XRD). Crystals of 1, 3, 5, 6, and 7 suitable for XRD were obtained. The crystal structures of 3 and 5 have been previously reported [47][61][62][63]. The crystal structures of 1, 6, and
  • basis (0.55 kcal/mol). In the crystal structures of 3, 5, 6, and 7, the geometric relationship between the LPE of nitrogen and the antibonding σ orbital C–H(7)eq promotes the nN→σC–H(7)eq interaction, which is caused by the N(3)–C(7)–Heq angle being near 160° (Table 1). Furthermore, the N(3) ∙∙∙C(7
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Published 22 Oct 2015

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

  • Chao Chen,
  • Chunxin Lu,
  • Qing Zheng,
  • Shengliang Ni,
  • Min Zhang and
  • Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

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  • corresponding nickel–NHC complexes with [Ru(p-cymene)2Cl2]2 in refluxing acetonitrile solution. The crystal structures of three complexes determined by X-ray analyses show that the central Ru(II) atoms are coordinated by pyrimidine- or pyridine-functionalized N-heterocyclic carbene and acetonitrile ligands
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Published 30 Sep 2015

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

  • Masahiko Iyoda and
  • Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

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  • bonding, metal coordination, CT interaction, π···π stacking, van der Waals interaction, etc.) play an important role in the formation of the three-dimensional (3D) crystal structures [5]. For the construction of nanostructured objects, π···π, S···S, and other weak intermolecular interactions first
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Published 10 Sep 2015

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

  • David W. Manley and
  • John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

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  • excitation wavelength 385 nm, band gap 3.2 eV). Whilst this is less convenient than visible light, the band edge positions are consequently more powerful redox agents. Of the naturally occurring crystal structures of TiO2, anatase is superior to rutile for photocatalytic activity [12]. For semiconductor
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Published 09 Sep 2015

Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes

  • Sara J. Krivickas,
  • Chiho Hashimoto,
  • Junya Yoshida,
  • Akira Ueda,
  • Kazuyuki Takahashi,
  • John D. Wallis and
  • Hatsumi Mori

Beilstein J. Org. Chem. 2015, 11, 1561–1569, doi:10.3762/bjoc.11.172

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  • 0.5 μA under a N2 atmosphere during the course of 6 days. The other chiral brown plate crystal of α’-[(R,R)-2]2ClO4(H2O) was prepared electrochemically by utilizing (R,R)-2 (5 mg) and tetrabutylammonium perchlorate (40 mg) in dichloromethane (9 mL) at 0.5 μA for 5 days. Crystal structures of achiral
  • electrode: Pt, counter electrode: Pt wire, reference electrode: saturated calomel electrode (SCE)) [22]. EI-mass spectra were obtained with a JEOL JMS-AX500 spectrometer. X-ray crystallographic measurements were made on a Rigaku AFC-7R diffractometer (Mo Kα, λ = 0.71073 Å). The crystal structures were
  • )- and (S,S)-2, and the preparation, and crystal structure of the radical cation salt α’-[(S,S)-2]2ClO4 [22] have been reported. In this article, we report the syntheses of novel racemic-1 and enantiopure (R,R)- and (S,S)-2 possessing one or two hydroxymethyl groups, and the preparations, crystal
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Published 08 Sep 2015

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes

  • George Iakobson,
  • Junyi Du,
  • Alexandra M. Z. Slawin and
  • Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

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  • (Table 2). Crystal structures of 3a (CCDC 1009848) and 3b (CCDC 1009849) were determined confirming the nature of the products. During the course of our studies, Okazaki and co-workers reported the synthesis of 3b in 84% yield under similar conditions and have shown its reactivity in various cross
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Published 26 Aug 2015

A novel and widespread class of ketosynthase is responsible for the head-to-head condensation of two acyl moieties in bacterial pyrone biosynthesis

  • Darko Kresovic,
  • Florence Schempp,
  • Zakaria Cheikh-Ali and
  • Helge B. Bode

Beilstein J. Org. Chem. 2015, 11, 1412–1417, doi:10.3762/bjoc.11.152

Graphical Abstract
  • could be obtained due to low expression levels under all conditions tested. The homodimeric structure of OleA from Xanthomonas campestris, showing the highest sequence identity (27%) of all available crystal structures at the PDB [21], was used as a template. OleA is responsible for the head-to-head
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Published 12 Aug 2015

Azobenzene-based inhibitors of human carbonic anhydrase II

  • Leander Simon Runtsch,
  • David Michael Barber,
  • Peter Mayer,
  • Michael Groll,
  • Dirk Trauner and
  • Johannes Broichhagen

Beilstein J. Org. Chem. 2015, 11, 1129–1135, doi:10.3762/bjoc.11.127

Graphical Abstract
  • synthesized a small library of nine azobenzene sulfonamides with differing substitution patterns in the 4´-position using either azo coupling reactions or the Mills reaction. We determined the π–π* band and the crystal structures of all nine compounds together with the protein crystal structure of hCAII bound
  • hCAII. a) hCAII (pdb: 2vva [7]) catalyzes the hydration of carbon dioxide to bicarbonate and a proton (left) as well as the hydrolysis of pNPA to acetate and a colored phenolate (λmax = 400 nm). b) Aryl sulfonamide-containing pharmacophores of hCAII. c) Aryl sulfonamide merged to azobenzenes. Crystal
  • structures for compounds 1a–i (co-solvents and/or multiple molecules in the asymmetric cell are omitted for clarity). Crystal structure of hCAII bound to 1d (pdb: 5byi). a) The terminal amine of 1d is solvent-exposed, while the azobenzene is sticking in the cavity. b) Electron-density map of 1d bound to zinc
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Published 07 Jul 2015

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

  • Flavia Pop and
  • Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

Graphical Abstract
  • conformation. Cyclic voltammetry measurements indicate fully reversible oxidation in radical cation and dication species. Keywords: chirality; crystal structures; molecular materials; sulfones; tetrathiafulvalenes; Introduction Chiral tetrathiafulvalene (TTF) derivatives have been addressed for the first
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Published 02 Jul 2015

Indolizines and pyrrolo[1,2-c]pyrimidines decorated with a pyrimidine and a pyridine unit respectively

  • Marcel Mirel Popa,
  • Emilian Georgescu,
  • Mino R. Caira,
  • Florentina Georgescu,
  • Constantin Draghici,
  • Raluca Stan,
  • Calin Deleanu and
  • Florea Dumitrascu

Beilstein J. Org. Chem. 2015, 11, 1079–1088, doi:10.3762/bjoc.11.121

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  • primary cycloadduct 19 which spontaneously rearranges and dehydrogenates under the reaction conditions, to the final aromatic compounds 20. X-ray crystal structures of the starting compounds 4-(2-pyridyl)pyrimidine (6) and 4-(4-pyridyl)pyrimidine (8) Full details of the structural solution and refinements
  • parent atoms were either fully occupied by carbon atoms or by nitrogen atoms, or partially occupied by carbon and nitrogen atoms simultaneously. Figure 4a and 4b show the molecular and crystal structures of 4-(2-pyridyl)pyrimidine (6). Here, all atoms in the molecule have a site-occupancy factor (s.o.f
  • -pyridylpyrimidines 6–8. The 1H NMR spectra (DMSO-d6) of 4-(2-pyridyl)pyrimidine (6) and the corresponding bromides 11a–e (the aromatic region). Molecular and crystal structures of 6 (a,b) and 8 (c,d). The molecules are located on centers of inversion and their asymmetric units are labelled, disordered atoms being
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Published 26 Jun 2015

Donor–acceptor type co-crystals of arylthio-substituted tetrathiafulvalenes and fullerenes

  • Xiaofeng Lu,
  • Jibin Sun,
  • Shangxi Zhang,
  • Longfei Ma,
  • Lei Liu,
  • Hui Qi,
  • Yongliang Shao and
  • Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 1043–1051, doi:10.3762/bjoc.11.117

Graphical Abstract
  • other hand, the interaction between the aryls and fullerene molecules is very important to stabilize the structure of the co-crystals as reported in the crystal structures section. For Ar-S-TTFs exhibiting E1/21 > 0.6 V, the aryl groups are more electron deficient than the phenyl [61][62]. The
  • ratio of the co-crystals, this work further demonstrates that Ar-S-TTFs are promising candidates to serve as receptors for fullerenes and have diverse supramolecular structures. Crystal structures The single crystalline structure of the complex is suitable for X-ray single crystal diffraction
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Published 19 Jun 2015

Tuning the size of a redox-active tetrathiafulvalene-based self-assembled ring

  • Sébastien Bivaud,
  • Sébastien Goeb,
  • Vincent Croué,
  • Magali Allain,
  • Flavia Pop and
  • Marc Sallé

Beilstein J. Org. Chem. 2015, 11, 966–971, doi:10.3762/bjoc.11.108

Graphical Abstract
  • , mastering the geometry of multicomponent redox-active systems offers a unique opportunity to fine-tuning electronic interactions within the material [43], an issue which is of prime importance for optimizing electron transport in organic materials. X-ray crystal structures of: (a) ligand L1, (b) self
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Published 05 Jun 2015

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

  • Huixin Jiang,
  • Virginia Mazzanti,
  • Christian R. Parker,
  • Søren Lindbæk Broman,
  • Jens Heide Wallberg,
  • Karol Lušpai,
  • Adam Brincko,
  • Henrik G. Kjaergaard,
  • Anders Kadziola,
  • Peter Rapta,
  • Ole Hammerich and
  • Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

Graphical Abstract
  • . Oxidation: Cyclic voltammograms of compounds 1a, 2a, 3b, and 4–8 measured at a glassy carbon electrode are shown in Figure 4 [19] and redox potentials are listed in Table 1 together with the shortest TTF (C=C)–TTF (C=C) distance in each structure (obtained from the crystal structures or from DFT
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Published 02 Jun 2015

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

  • Vladimir A. Azov,
  • Diana Janott,
  • Dirk Schlüter and
  • Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

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  • MPTTF aromatic derivatives, whose properties and crystal structures are discussed below. Results and Discussion Synthesis Our initial synthetic efforts were focused on optimizing reaction conditions using the PrS-MPTTF derivative 7a [23] and bromoanisole 8a as starting materials (Scheme 2), as well as
  • and 1.77 V, in 4e and 4f (see Figure S7, Supporting Information File 1), respectively. For the phenol derivative 4f, this oxidation is irreversible. Crystal structures Compounds 4a,b,d,e afforded high quality crystals that could be analysed using X-ray crystallography, allowing to unambiguously
  • derivative has an almost planar arrangement of the TTF moiety, whereas N-alkyl derivatives show significant deviation from planarity [12]. Interestingly, the crystal structures of all four compounds feature similar packing arrangements with two crystallographically distinct molecules (Z’ = 2) with quasi
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Published 21 May 2015

Copper ion salts of arylthiotetrathiafulvalenes: synthesis, structure diversity and magnetic properties

  • Longfei Ma,
  • Jibin Sun,
  • Xiaofeng Lu,
  • Shangxi Zhang,
  • Hui Qi,
  • Lei Liu,
  • Yongliang Shao and
  • Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 850–859, doi:10.3762/bjoc.11.95

Graphical Abstract
  • report [37][38], and their electrochemical activities as well as the crystal structures have been fully elucidated [38][39]. Since the redox potentials of TTFs are very important in the formation of complexes, particularly on the charge-transfer degree, the first (E1/21) and the second (E1/22) redox
  • . Crystal structure The single crystals for all of the present salts were suitable for the X-ray single crystal diffraction analyses. Herein, we report the crystal structures of the typical salts (Figures 1–5), and those of the others are supplied in Supporting Information File 1. As mentioned above, the
  • discuss the crystal structures of these salts, including the molecular geometry of TTFs, the structure of anions, and the packing motifs. 1·CuBr4 crystallizes in the orthorhombic Pbcn space group with half of molecule 1 and half of CuBr4 crystallographically unique (Figure 1a). The central TTF core on 1
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Published 20 May 2015

Trifluoromethyl-substituted tetrathiafulvalenes

  • Olivier Jeannin,
  • Frédéric Barrière and
  • Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

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  • < CO2Me < CF3 < CN, as discussed above (Table 1 and Table 2). X-ray crystal structures of the neutral donor molecules As mentioned in the Introduction, the substitution of one hydrogen atom on the TTF core by one EWG such as ester or cyano group is known to distort the dithiole ring, as illustrated in
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Published 06 May 2015

TTFs nonsymmetrically fused with alkylthiophenic moieties

  • Rafaela A. L. Silva,
  • Bruno J. C. Vieira,
  • Marta M. Andrade,
  • Isabel C. Santos,
  • Sandra Rabaça,
  • Dulce Belo and
  • Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

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  • , respectively. These electrochemical studies show that α-tbtdt and α-mtdt are easier to oxidise than the related unsubstituted extended TTFs, with higher electron donor ability compared to related TTF-type donors with the exception of BET-TTF. Crystal structures Ketone I Compound I crystallises in the
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Published 05 May 2015

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

  • Nikolai V. Rostovskii,
  • Mikhail S. Novikov,
  • Alexander F. Khlebnikov,
  • Galina L. Starova and
  • Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

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  • -azabuta-1,3-dienes which transform back to the oxazines in the dark at room temperature. The rate of the reverse cyclization reaction increases with increasing electron-withdrawing ability of C1-substituent in 2-azabuta-1,3-diene. X-ray crystal structure of azadiene 3e. X-ray crystal structures of
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Published 02 Mar 2015

Molecular cleft or tweezer compounds derived from trioxabicyclo[3.3.1]nonadiene diisocyanate and diacid dichloride

  • Gert Kollenz,
  • Ralf Smounig,
  • Ferdinand Belaj,
  • David Kvaskoff and
  • Curt Wentrup

Beilstein J. Org. Chem. 2015, 11, 1–8, doi:10.3762/bjoc.11.1

Graphical Abstract
  • minima [1]. Optimization of the endo,exo structure leads to ring opening to a new diisocyanate (Scheme 1). Therefore, it is of some importance to ascertain the actual molecular structures of compounds of this type by X-ray crystallography. Here we report the X-ray crystal structures of two derivatives of
  • in Supporting Information File 1). It is seen in the crystal structures depicted in Figures 3–5 that compounds 4 and 5 (and therefore also 1) exist in the endo,endo structures, and each functional group is surrounded by three tert-butyl groups, which direct these functional groups away from the ether
  • close proximity. Calculations The structures of 4 and 5 were calculated at the B3LYP/6-31G** level, which reproduces the crystal structures very well, as demonstrated in Figure 6 and Figure 7 and in Figure S2 and Figure S3 (Supporting Information File 1). While there are several possible conformations
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Published 02 Jan 2015
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