Aryl substitution of pentacenes

• Andreas R. Waterloo,
• Anna-Chiara Sale,
• Dan Lehnherr,
• Frank Hampel and
• Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

• properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of

• (vide infra). Thermal analysis The thermal stability of selected aryl pentacenes has been explored by traditional melting point analysis (MPA) in open capillary tubes, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) measurements; the results are summarized in Table 2. TGA

• TGA data with that of MPA made in open capillary tubes, however, it is clear that all pentacene derivatives undergo either a phase change or decomposition prior to the mass loss observed in the TGA. This premise is also confirmed by DSC analyses, which show a melting point in all cases except for

Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

• Simon Rondeau-Gagné,
• Jules Roméo Néabo,
• Maxime Daigle,
• Katy Cantin and
• Jean-François Morin

Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167

• samples were prepared with PAM1 and PAM2 in cyclohexane at a 10 mg/mL concentration and subjected to differential scanning calorimetry (DSC). The DSC analysis was carried out at temperatures ranging from 298 to 223 K. In both cases, a very sharp exotherm attributable to the crystallization of supercooled

Nonanebis(peroxoic acid): a stable peracid for oxidative bromination of aminoanthracene-9,10-dione

• Vilas Venunath Patil and
• Ganapati Subray Shankarling

Beilstein J. Org. Chem. 2014, 10, 921–928, doi:10.3762/bjoc.10.90

• very good properties [32] such as a high active oxygen content (14.4%) and insusceptibility to shock. The Differential Scanning Calorimeter (DSC) analysis data confirm the non-shock-sensitive nature of nonanebis(peroxoic acid). Details are given in Supporting Information File 2, pages S35–S36. The most

• recorded using Varian spectraprobe and Bruker 400 ultrashield (Advance 400 NMR spectrometer) and chemical shifts are expressed in δ ppm using TMS as an internal standard. Mass spectral data were obtained with a Micromass Q-TOF spectrometer. The DSC analysis was done using a DSC Q100 V9.9 Build 303

• File 209: Characterization details for all the products in Table 4. Supporting Information File 210: FTIR, mass and 1H NMR spectra of all products in Table 4, Differential Scanning Colorimetric (DSC) analysis and calculations for shock sensitivity of nonanebis(peroxoic acid), HPLC analysis details

The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• . Phase behavior Thermal properties By means of polarized optical microscopy (POM) and differential scanning calorimetry (DSC) we investigated the thermal properties of the macrocycles 1–4. The transition temperatures are shown in Figure 3 and listed in Table 1. Extraannular substitution It is well known

• crystallinity in 2. From the DSC and POM investigations in combination with the chemical structure of the compounds the following observations can be summarized: Although 1d has an empty lumen it has a similar melting point (62 °C) as 1a (63 °C), whose cavity crosses an alkyl bridge. Prolonging the intraannular

• temperatures, the mesophases of both, 1a and 1d, first solidify and slowly crystallize. The DSC results nicely confirm the POM observations. Corresponding endotherms for the melting and clearing points are visible in the thermograms of 1a as well as 1d (Figure 3b, Table 1). The sample of 1d seems to melt at 62

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

• Oliver Goerz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 902–909, doi:10.3762/bjoc.10.88

• with an accuracy of ±0.5 ° C in the measuring plate. The control of the thermostat (Haake DC30 or Haake AC 200-G50) was controlled by the software. Differential scanning calorimetry (DSC) measurements were performed by using a Mettler Toledo DSC 822 controller apparatus in a temperature range between 0

• (diamond) (cm−1): 2977, 2935, 2877 (ν, -CH2), 1729 (ν, C=O), 1639 (ν, C=C), 1151 (ν, C-O); GPC (THF): = 3452; D = 1.69; DSC: Tg = 64 °C. 1H NMR spectra of 3a (300 MHz, DMSO-d6). Oscillation measurements during thermal cross-linking of unsaturated polyester 13 with dinitrones 10a and 10b at 120 °C

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• compounds I–VI are summarized in Figure 2. A detailed description of synthetic procedures and characterization of all new intermediates and target compounds is summarized in Supporting Information File 1. All the compounds were studied by DSC, Table 1 summarizes the transition temperatures and associated

• enthalpy changes. The data are without electric field, the electro-optic measurements are discussed separately. DSC plots for three selected compounds IIb, IVb and Vb, taken on second heating and cooling runs are demonstrated in Figure 3. As it was reported for other bent-shaped materials [4][47][48][49

• in X-ray measurements. Experimental Measurements All compounds were studied using differential scanning calorimetry (DSC). The materials of 2–5 mg were hermetically closed in the aluminium pans and placed in nitrogen atmosphere of a Perkin–Elmer Pyris Diamond calorimeter. Cooling and heating rates of

Total synthesis and cytotoxicity of the marine natural product malevamide D and a photoreactive analog

• Werner Telle,
• Gerhard Kelter,
• Heinz-Herbert Fiebig,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2014, 10, 316–322, doi:10.3762/bjoc.10.29

• ) and acidic deprotection afforded diazirine diol 25. Figure 2 shows the DSC (differential scanning calorimetry) profile of 25, which melts at 54 °C and starts to decompose above 80 °C, indicating sufficient thermal stability for biological studies. Monosilylation of the primary hydroxy group of 25

• , and were able to identify α-tubulin as binding partner [22]. Structures of the strongly cytotoxic marine natural products malevamide D (1), isodolastatin H (2), and dolastatin 10 (3). DSC curve of diazirine 25, heating rate 5 °C/min. Total synthesis of malevamide D (1). a) DMSO (16 equiv), NEt3 (5

Cyclic phosphonium ionic liquids

• Sharon I. Lall-Ramnarine,
• Joshua A. Mukhlall,
• James F. Wishart,
• Robert R. Engel,
• Alicia R. Romeo,
• Masao Gohdo,
• Sharon Ramati,
• Marc Berman and
• Sophia N. Suarez

Beilstein J. Org. Chem. 2014, 10, 271–275, doi:10.3762/bjoc.10.22

• -cited Tm of −18 °C for C4mPyrr NTf2 was due to a metastable crystalline form by using an annealing process. The DSC scan of un-annealed C4mPphol NTf2 shows all the thermal features exhibited by un-annealed C4mPyrr NTf2 (glass transition, cold crystallization, solid–solid transition, and melting). When

• Supporting Information Detailed synthesis and characterization procedures are provided for all compounds synthesized and characterized. NMR spectra are provided for all compounds for which NMR data is reported. DSC thermograms are provided for the bis(trifluoromethylsulfonyl)amide ionic liquids (5a–5d

• ). Supporting Information File 8: NMR Spectra. Supporting Information File 9: DSC Thermograms. Supporting Information File 10: Experimental. Acknowledgements The authors thank the office of Educational Programs at Brookhaven National Laboratory and the NSF NYC Louis Stokes Alliance for Minority Participation

The difluoromethylene (CF₂) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF₂ groups

• Yi Wang,
• Ricardo Callejo,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2014, 10, 18–25, doi:10.3762/bjoc.10.4

• palmitic acids are characterized by differential scanning calorimetry (DSC) to determine melting points and phase behaviour relative to palmitic acid (62.5 °C). It emerges that 6c, with the CF2 groups placed 1,4- to each other, has a significantly higher melting point (89.9 °C) when compared to the other

• bond proved efficient and the resultant tetrafluoropentadecabenzene 26 was readily oxidized to palmitic acid 6c as illustrated in Scheme 2. This completed the syntheses of the palmitic acid analogues 6a–c. Differential scanning calorimetry (DSC) data was then measured for all three of the palmitic acid

• little influence on the melting point. For palmitic acid 6b, with the two CF2-groups placed 1,3 to each other, the melting point (69 °C) is also similar to palmitic acid, but the phase behaviour is more complex as evidenced by the broad DSC profiles. This palmitic acid 6b was amorphous in nature and was

Synthesis, characterization and initial evaluation of 5-nitro-1-(trifluoromethyl)-3H-1λ³,2-benziodaoxol-3-one

• Nico Santschi,
• Roman C. Sarott,
• Elisabeth Otth,
• Reinhard Kissner and
• Antonio Togni

Beilstein J. Org. Chem. 2014, 10, 1–6, doi:10.3762/bjoc.10.1

• of the I–CF3 bond should display a higher activation barrier. Recently, differential scanning calorimetry (DSC) measurements for reagent 2 and its precursors were published indicating a decomposition energy of 159 kJ/mol (502 J/g) for 2 [17]. Furthermore, a Koenen test suggested explosiveness

• . Consequently in light of these results, DSC measurements of 2 and 3 were carried out in order to assess the thermal stability of the new derivative. These measurements were performed in punctured Al2O3 pans with a heating rate of 10 K/min. For reagent 2, a decomposition energy of 138 kJ/mol (438 J/g, slightly

• X-ray structures 6 and 3. Thermal ellipsoids set to 30% probability. Hydrogen atoms omitted for clarity. DSC traces obtained for 2 (green) and 3 (blue). Cyclic voltammetry of 3 (1 mM, black) and of a mixture of 3 (1 mM) and methyl 2-iodo-5-nitrobenzoate (1 mM, green) in anhydrous MeCN + 0.1 M

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• with 10 mol % of Co2(CO)8 as the catalyst in refluxing 1,4-dioxane. The liquid crystalline properties were investigated by using polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Trimer 4 with an ester connecting group and a longer spacer

• oligomers. Mesomorphism POM and DSC Initially, we studied the mesomorphic properties of the monomers and trimers by using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The POM results of the monomers and trimers are summarized in Figure 1 and Figure 2, respectively. The

• DSC traces are shown in Figure 3 and the phase transition data are summarized in Table 1. For the mesomorphism of the functionalized triphenylene monomers, compound 2 [52] and 3b [57] have been reported, 3a and 3c are new. They all display typical optical textures with homeotropic alignment behavior

N,N'-(Hexane-1,6-diyl)bis(4-methyl-N-(oxiran-2-ylmethyl)benzenesulfonamide): Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

• Julian Fischer,
• Simon Millan and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2834–2840, doi:10.3762/bjoc.9.318

• . The Sol–gel-transmission was determined by the first intersection of G’ and G’’. Graphs were plotted using reduced data, calculated by the median of three following values. The glass transition temperature (Tg) was determined using a Mettler Toledo DSC 822e equipped with a sample robot TSO801RO. For

Oligomeric epoxide–amine adducts based on 2-amino-N-isopropylacetamide and α-amino-ε-caprolactam: Solubility in presence of cyclodextrin and curing properties

• Julian Fischer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2803–2811, doi:10.3762/bjoc.9.315

• products 9 and 10 is assumed to be caused by the different shape of side groups of the oligomers. Additional proof of the different chain flexibility of the cured products 9 and 10 was conducted using DSC measurements. As expected, the Tg (glass transition temperature) of 9 (Tg = 6 °C) was significant

• first three intersections of G’ and G’’ taking initial fluctuations due to homogenization and sheer-thinning processes not into account. Glass transition temperatures (Tg) were determined using a Mettler Toledo DSC 822e equipped with a sample robot TSO801RO. For calibration, standard tin, indium, and

Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

• Peer Kirsch,
• Qiong Tong and
• Harald Untenecker

Beilstein J. Org. Chem. 2013, 9, 2367–2373, doi:10.3762/bjoc.9.272

• system equipped with a 7000A Triple Quad detector. Melting points were determined by differential scanning calorimetry (DSC) performed on a Universal V4.5A (TA Instruments) at a heating/cooling rate of 20 K∙min−1. The temperature was calibrated with indium. The measurements were performed under a

Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

• Marta Pérez-Torralba,
• Rosa M. Claramunt,
• M. Ángeles García,
• Concepción López,
• M. Carmen Torralba,
• M. Rosario Torres,
• Ibon Alkorta and
• José Elguero

Beilstein J. Org. Chem. 2013, 9, 2156–2167, doi:10.3762/bjoc.9.253

• . Experimental General Information. All chemicals cited in the synthetic procedures are commercial compounds. Melting points were determined by DSC with a SEIKO DSC220C connected to a model SSC5200H disk station. Thermograms (sample size 0.004 g) were recorded with a scan rate of 5.0 °C. Column chromatography

Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

• Christian Dollendorf,
• Martin Hetzer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 1652–1662, doi:10.3762/bjoc.9.189

• determined using differential scanning calorimetry (DSC). As a reference poly(DEAAm-co-DMAEMA, 1:1) (3) with a Tg of 43 °C was used. Cross-linking with CL 2 slightly increases the Tg from 43 to 47 and 49 °C for 5a, 5b and 5c, respectively. In contrast, samples containing CL 1 showed a stronger influence of

Synthesis of guanidinium–sulfonimide ion pairs: towards novel ionic liquid crystals

• Martin Butschies,
• Manuel M. Neidhardt,
• Markus Mansueto,
• Sabine Laschat and
• Stefan Tussetschläger

Beilstein J. Org. Chem. 2013, 9, 1093–1101, doi:10.3762/bjoc.9.121

• % yield, respectively. In comparison the guanidinium iodide 7∙I was obtained in 94% yield by heating 7∙Cl with KI in MeCN under reflux (Scheme 3). The mesomorphic properties of ion pairs 2,3 and guanidinium halides 7∙I, 7∙Cl, 8∙I were studied by differential scanning calorimetry (DSC) and polarizing

• optical microscopy (POM). The results of the DSC experiments are summarized in Table 1. N-Methylated guanidinium sulfonimides 2a,b revealed only isotropic melting at 61 °C and 93 °C, respectively (Table 1, entries 1 and 2), while N-methylated guanidinium iodide 8∙I melted at 117 °C (Table 1, entry 3). In

• , sulfonimide-containing ion pair 3b indeed led to a mesophase albeit with only 16 K phase width as compared to 49 K phase width of the guanidinium sulfonate 1. The DSC traces of 3b are shown in Figure 1. POM observations of 3b upon cooling from the isotropic liquid revealed fan-shaped textures and homeotropic

1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

• Astrid Hoppe,
• Faten Sadaka,
• Claire-Hélène Brachais,
• Gilles Boni,
• Jean-Pierre Couvercelle and
• Laurent Plasseraud

Beilstein J. Org. Chem. 2013, 9, 647–654, doi:10.3762/bjoc.9.73

• pentaerythritol as initiator alcohols, and the products were fully characterized by 1H and 13C{1H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating

• spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Polymerization data are summarized in Table 1 and Table 2. As shown in Table 1 and Table 2, full conversion is observed for all ROPs of ε-caprolactone initiated by the various alcohols while conversions in the range

• differential scanning calorimetry is summarized in Table 4. DSC profiles are depicted in Supporting Information File 2 (Figure S1). Samples with molecular weight in the 1100–1500 Da range (Table 4), show similar Tm and Tc, although the endings of the chains are different. However, values for the crystallinity

Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

• Alexej Bubnov,
• Miroslav Kašpar,
• Věra Hamplová,
• Ute Dawin and
• Frank Giesselmann

Beilstein J. Org. Chem. 2013, 9, 425–436, doi:10.3762/bjoc.9.45

• evaluated from differential scanning calorimetry (DSC) measurements. Thermotropic liquid-crystalline properties of all compounds under study are summarized in Table 2. On cooling from the isotropic state, TL1 and TL4, with quite a different structure of the molecular core and aliphatic chains (see Table 1

• obtained at 108 °C on free-standing films (FSF) (Figure 1b), and the N–SmC phase transition obtained at about 102 °C on FSF (Figure 1c). DSC plot on heating/cooling runs for indicated nonchiral TL1, TL3 and TL4 and for chiral TL2 and TL5 are presented in Figure 2 and Figure 3, respectively. The blue phase

• (BPII) and the cholesteric phase (N*) have been detected for the chiral TL2. The peak corresponding to the Iso-BPII phase transition has not been detected by DSC and the temperature of this phase transition has been taken from observations obtained by POM (Table 2). The type of the blue phase (BPII) has

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

• enthalpy change ΔH, entropy change ΔS, transition temperature T1/2, and occurrence of hysteresis, DSC measurements down to liquid-nitrogen temperatures are sufficient in most cases [91][92][93][94]. Diffraction Methods The rearrangement of the valence electrons among the antibonding eg orbitals and the

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• . Results and Discussion Thermal analysis Figure 2 shows representative thermogravimetric (TGA) and differential scanning calorimetric (DSC) traces for the novel inclusion complex DIMEB·1. Three reproducible thermal events occur in the DSC trace, the first of which is a small endotherm at 132 °C, which we

• differential scanning calorimetric trace was recorded on a DSC-Q200 calorimeter, TA instruments. For both techniques, a heating rate of 10 K min−1 and dry nitrogen purge gas flowing at a rate of 30 mL min−1 were employed. Crystals were transferred to an open alumina or aluminium crucible in the case of TG

• measurements and closed vented aluminium pans for DSC measurements. Sample masses were between 0.5 and 2.0 mg for DSC measurements and between 2 and 8 mg for the TG runs. Kinetic procedures The kinetic procedures were described previously [6]. The DIMEB molecule has hydroxy groups that can be deprotonated by

Glycosylation efficiencies on different solid supports using a hydrogenolysis-labile linker

• Mayeul Collot,
• Steffen Eller,
• Markus Weishaupt and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 97–105, doi:10.3762/bjoc.9.13

• resins, an additional Zemplén cleavage site for fast LC–MS analysis is introduced. Synthesis of linker 1. Reactions and conditions: (a) NEt3, DCM, rt, 84%; (b) DHP, pyridinium p-toluenesulfonate, DCM, rt, quant.; (c) 2 M aq NaOH, THF, rt, 91%; (d) DSC, NEt3, CH3CN, 0 °C to rt; (e) NEt3, DCM, rt, 80% over

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

• is more stable towards hydrolysis due to intramolecular hydrogen bonding. We report here the synthesis and characterization of the compounds 1a–1f (Scheme 1) by elemental analysis, spectroscopic data, polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Results and

• calorimetry (DSC). The thermodynamic data are presented in Table 1. A representative DSC trace obtained during the initial heating and cooling cycles scanned at a rate of 10 K min−1 for 1c is presented in Figure 2. The nematic–isotropic phase-transition enthalpies are of the order of 0.15~0.29 kJ/mol for 1a

• have been designed and synthesized, and mesomorphism has been confirmed in these polar molecular architectures. The thermal behaviour of the novel four-ring compounds has been investigated by DSC and POM. The compounds derived from transverse and terminal polar substituents in the bent-core molecules

Influence of cyclodextrin on the solubility and the polymerization of (meth)acrylated Triton^® X-100

• Melanie Kemnitz and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2176–2183, doi:10.3762/bjoc.8.245

• tert-octyl group were broader after the polymerization. The 2D-ROESY spectrum indicates that the complex was still intact after the polymerization (Supporting Information File 1, Figure S3). DSC measurements of the dried samples indicate a high influence of RAMEB-CD. The Tg value was found to be about

• /min. For detection a Viscotek VE 3500 RI detector was used. The system was calibrated with polystyrene standards within a molecular range from 575 to 3,114,000 g/mol. On a Mettler Toledo DSC 822 instrument the DSC measurements were determined in a range of −50 to 200 °C at the heating rate of 10 °C

Cyclodextrin-based nanosponges as drug carriers

• Francesco Trotta,
• Marco Zanetti and
• Roberta Cavalli

Beilstein J. Org. Chem. 2012, 8, 2091–2099, doi:10.3762/bjoc.8.235

• increasing its aqueous solubility, and formed inclusion complexes. FTIR, DSC and XRPD analyses confirmed the drug interaction with nanosponges. Moreover camptothecin loaded in nanosponges was seen to be more effective than the plain drug on HT29 cells. The same formulation was recently shown to be an

• many essential oils and fragrances with a boiling point of 198 °C, was encapsulated in different types of nanosponges as a liquid oil model [43]. β-CD-1/4 nanosponges can incorporate 8% w/w of linalool within their structure. The entrapment of linalool in the nanosponge matrix was confirmed by DSC