Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• phosphorylcholine (MPC), these single-chain-stranded loose-fit PPRs were transformed into conformational identical polyrotaxanes (PRs). The structures of the PPRs and PRs were characterized by means of 1H NMR, GPC, 13C CP/MAS NMR, 2D 1H NOESY NMR, FTIR, WXRD, TGA and DSC analyses. Keywords: ATRP; γ-CD; double

• -PPO-PMA with the varying amount of γ-CDs [10][11][12]. The DSC measurements of PPRs and PRs were also conducted in this study. As shown in Figure 9, BrPEPBr reveals an endothermic peak at 51.8 °C, corresponding to the melting point of the PEO crystalline phase. As for PEP100M, a lower melting point

• FTIR spectrometer at room temperature using the KBr pellet method. TGA analysis was performed with using a TA SDT 2960 instrument at a heating rate of 10 °C/min from room temperature to 500 °C in a nitrogen atmosphere. DSC measurements were measured on a SHIMADZU DSC-60 differential scanning

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• MHz (13C NMR); CDCl3 (Aldrich) was used as solvent. Chemical shifts δ were reported in parts per million relative to the residual CHCl3 signal as an internal reference standard. Differential scanning calorimetry (DSC) thermograms were recorded on a Mettler TA 4000 system at a rate of 10 °C/min under

• mixture to 0.2 mL of ethyl vinyl ether, stirred for 30–40 min at ambient temperature, and concentrated in vacuum, after that CDCl3 was added. For DSC and GPC measurements, the copolymers were precipitated in ethanol and dried as described above. A typical 13C NMR spectrum is shown in Figure 11

• PCOE with PNB. Static scattering intensity from different CHCl3 solutions: Acknowledgements The authors are thankful to M. Yu. Gorshkova and to G. A. Shandryuk (Topchiev Institute of Petrochemical Synthesis RAS) for performing the GPC and DSC measurements, respectively. The work was partially

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

• (DSC), positive electrode materials for rechargeable batteries, and electrochromic (EC) materials [1]. TTF derivatives are versatile building blocks to form aggregates in the solid state with interesting conducting and magnetic behavior [2]. Although these properties are mainly originated from specific

Thermal properties of ruthenium alkylidene-polymerized dicyclopentadiene

• Yuval Vidavsky,
• Yotam Navon,
• Yakov Ginzburg,
• Moshe Gottlieb and
• N. Gabriel Lemcoff

Beilstein J. Org. Chem. 2015, 11, 1469–1474, doi:10.3762/bjoc.11.159

• Differential scanning calorimetry (DSC) analysis of ring opening methatesis polymerization (ROMP) derived polydicyclopentadiene (PDCPD) revealed an unexpected thermal behavior. A recurring exothermic signal can be observed in the DSC analysis after an elapsed time period. This exothermic signal was found to be

• of 98.9% at polymerization temperatures of 60 °C with the Grubbs first generation catalyst. By carrying out detailed differential scanning calorimetry (DSC) analyses Kessler and Mauldin [27] demonstrated a sharp exothermic peak related to the heat of reaction and a final Tg of 164 °C at conversions

• of 90% right after curing. Dimonie et al. [28][29] examined the nature of the first exothermic peak of linear PDCPD using DSC and showed thermal polymerization completion after 2 h at 150 °C as the exothermic peak disappeared given these conditions. Kessler and White [30] also explored the cure

Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

• Karolina Żukowska,
• Eva Pump,
• Aleksandra E. Pazio,
• Krzysztof Woźniak,
• Luigi Cavallo and
• Christian Slugovc

Beilstein J. Org. Chem. 2015, 11, 1458–1468, doi:10.3762/bjoc.11.158

• reaction and responsible for the low(er) polymer yields and pronounced endothermic signals in the DSC traces (cf. Figure 9 right) [58]. While initiator 5a shows an appealing performance in polymerizing 23, the electronically modified congeners 14 and 15 are not particularly interesting for this application

• . Big symbols: thermogravimetric analysis (TGA); no symbols: differential scanning calorimetry (DSC). trans–cis Isomerization. Synthesis of the ligand precursors. Synthesis of the ruthenium complexes. Possible reaction pathways of 16. Supporting Information Supporting Information File 360: Full

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• synthesized hexa-peri-hexabenzocoronene cyclophane 201a–c. They studied their properties by carrying out differential scanning calorimetry (DSC), optical microscopy, wide-angle X-ray scattering (WAXD), and scanning tunneling microscopy (STM). Tunneling spectroscopy reveals a diode-like behavior which

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial

• calorimetry (DSC). The DSC curves of the cholesterol-based supramolecular complexes are shown in Figure 2 and phase transition temperatures are listed in Table 1. The DSC thermogram of M0 presented three peaks at 158, 211 and 249 °C on heating, corresponding to the crystal to crystal transition, crystal to

• mesophase transition and mesophase to isotropic transition. On the cooling run, DSC curves presented isotropic phase to mesophase, mesophase to crystal and crystal to crystal at 190, 155 and 126 °C. Each curve of compounds M2, M6 and M10 displayed a single endothermic melting peak. The heating DSC curves of

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

• Yunfei Wang and
• Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

• of 9). It is therefore reasonable to propose that the microporosity in 8 is directly related to the coordination polymer structure. Finally, the thermal stability of coordination polymer 8 and Zn-DTF 9 were evaluated by differential scanning calorimetric (DSC) analysis, and detailed DSC traces are

• illustrated in Figure 6. The DSC data of Zn-TTFV 8 (Figure 6A) manifested very good thermal stability up to 400 °C, without any significant melting or decomposition except a slight phase transition at 272 °C. Comparatively, the DSC trace of carboxyl-TTFV ligand 6 showed a distinctive melting process at 317 °C

• significant exothermic peak at 358 °C (Figure 6C). For carboxyl-DTF 7, a notable melting point was observed at 199 °C, and the melting was followed by certain exothermic processes in the range of 200 to 285 °C. The DSC results indicated that the formation of Zn-TTFV coordinate polymer could give rise to

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• the compounds, i.e., the 13a (PhOx.C*Cn) and the 13b (C12.Ox.C*Cn) series are carried out by a Shimadzu (DSC-60) differential scanning calorimeter (DSC). The heating and cooling rates applied for the thermal studies are 10 °C/min. The thermograms of 13ap and 13bp are given in Figure 4 as

• 13b (C12.Ox.C*Cn) are presented in Table 1 and Table 2, respectively. The phase diagrams are constructed with DSC cooling cycle data of the 13a (Ph.Ox.C*Cn) and the 13b (C12.Ox.C*Cn) series and are presented in Figure 5 and Figure 6, respectively. It is realized that the compounds of the 13a (Ph.Ox.C

• fan texture exhibited by 13ar (Ph.Ox.C*C10) at 120 °C. (b) Broken focal conic fan texture exhibited by 13br (C12.Ox.C*C10) at 65 °C. Polarization profile of 13br (C12.Ox.C*C10) compound at 65 °C. Temperature dependant spontaneous polarisation in 13bp and 13br. DSC thermograms of 13ap and 13bp. Phase

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• of the interaction between α-CD and RSV, for example, the disappearance of the melting endotherm for RSV in the differential scanning calorimetric (DSC) trace of the product was cited as evidence for the formation of a α-CD·RSV complex [9]. The putative inclusion complex between β-CD and RSV

• co-crystallization from different solutions, by co-evaporation using a rotavapor, or by exposure to microwave radiation. Characterization of the products was achieved using DSC and simultaneous thermogravimetric analysis (TGA/DSC), with support from FTIR spectroscopy and PXRD, where necessary. An

• prepare the binary systems. Differential scanning calorimetry (DSC) indicated that the commercial product melted at Tpeak,m = 266.3(4) °C (Tonset = 265.1(3) °C; ΔHm = 279(2) J g−1) (Figure 2, curve (a)). Thermogravimetric analysis (TGA) revealed mass loss only at 275 °C attributable to sample

Modification of physical properties of poly(L-lactic acid) by addition of methyl-β-cyclodextrin

• Toshiyuki Suzuki,
• Ayaka Ei,
• Yoshihisa Takada,
• Hiroki Uehara,
• Takeshi Yamanobe and
• Keiko Takahashi

Beilstein J. Org. Chem. 2014, 10, 2997–3006, doi:10.3762/bjoc.10.318

• containing approximately 17% MeCD was drawn to more than 1000% at 60 °C, although PLLA fractured at a strain of less than 100%. Differential scanning calorimetry (DSC)-Raman in situ measurements also revealed decreases in the glass transition temperature (Tg), cold crystallization temperature (Tc), and

• melting point (Tm), and improvement in structural distribution with temperature. DSC-Raman measurements simultaneously supplied information about crystallinity and thermal properties. Thus, it was concluded that MeCD had high affinity for PLLA, and the addition of MeCD increased the amorphous component of

• PLLA and enhanced the drawability. Keywords: crystallinity; DSC; methyl-β-cyclodextrin; poly(L-lactic acid); Raman spectroscopy; Introduction Poly(L-lactic acid) (PLLA) has attracted attention because it is a biodegradable polymer derived from carbon-neutral resources. However, its melting point (Tm

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• formation was determined by thermal analysis (TG, DSC), FTIR and XRD. The quality of the encapsulation has been studied by gas chromatographic methods. Methylchavicol and other structurally related volatiles were also encapsulated in various natural CDs such as α- and β-CD, as well as in semisynthetic

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• molecular bromine which was used previously [33]. Thermal, electrochemical and optical properties TGA and DSC analyses All of the final target compounds showed good thermal stability. Thermogravimetric analysis (TGA) revealed decomposition temperatures in the range 396–442 °C (Table 1, Figure S1, Supporting

• Information File 1). The morphological stability was evaluated by differential scanning calorimetry (DSC). All of the synthesised compounds were found to be amorphous materials and exhibited reasonably high glass transition temperatures (Tg) (Table 1, Figure S2, Supporting Information File 1). The Tg value

• Perkin-Elmer Thermogravimetric Analyser TGA7 under a constant flow of argon. Differential Scanning Calorimetry (DSC) was conducted on a TA Instruments Q1000 with a RC-90 refrigerated cooling unit attached. The calibration was conducted using indium (melt temperature 156.42 °C, ∆Hf 28.42 J/g). The test

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• isotherms and in the solid state by thermal analysis (DSC) and X-ray diffractometry. The variation of the alkyl chain structure of the p-hydroxybenzoic acid esters revealed that the stability of the inclusion complexes was deeply modified (see binding constants in Table 3). As depicted in Table 3, the

• problem of unstability of chloramine phosphate (chloramidophos, see Figure 3) as a pesticide by the formation of 1:1 inclusion complexes with β-CD [49]. The formation of inclusion complex was proved by DSC, Fourier transform infrared and X-ray diffraction [50]. The binding constant was estimated at 203 M

• delivery applications [51]. The inclusion complexes were prepared by the freeze-drying method and characterized by transmission electronic microscopy, oxidative DSC and phase solubility. The encapsulation efficiency was very high for all the essential oils. The phase solubility method was typical of a 1:1

Loose-fit polypseudorotaxanes constructed from γ-CDs and PHEMA-PPG-PEG-PPG-PHEMA

• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2014, 10, 2461–2469, doi:10.3762/bjoc.10.257

• -CDs to give rise to tight-fit double-chain stranded polypseudorotaxanes (PPRs). After attaching the PHEMA, the resulting pentablock copolymer was single-chain stranded into the interior of γ-CDs to form more stable, loose-fit PPRs. The results of 1H NMR, WXRD, DSC, TGA, 13C CP/MAS NMR and FTIR

• with γ-CDs in aqueous solution to form PPRs. The results of 1H NMR, WXRD, DSC, TGA, 13C CP/MAS NMR and FTIR analyses indicate that the attachment of PHEMA clearly changes the self-assembly direction of γ-CDs with PHEMA-PPO-PEO-PPO-PHEMA. This results in unique, single-chain stranded, loose-fit PPRs

• the decrease in conformational flexibility upon PPR formation. Furthermore, this indicates that a number of γ-CDs can still be held on the pentablock copolymer axle at a higher feed molar ratio, even in a highly polar DMSO solvent as previously described [25]. DSC measurements provide further evidence

Oligomerization of optically active N-(4-hydroxyphenyl)mandelamide in the presence of β-cyclodextrin and the minor role of chirality

• Helmut Ritter,
• Antonia Stöhr and
• Philippe Favresse

Beilstein J. Org. Chem. 2014, 10, 2361–2366, doi:10.3762/bjoc.10.246

• 500. MALDI–TOF spectra were performed on a Bruker Ultraflex TOF mass spectrometer, the molecular masses being recorded in linear mode. Dithranol was used as a matrix and sodium trifluoroacetate (NaTFA) as ionization reagent. The samples were dissolved in DMF. DSC measurements were performed using a

• Mettler Toledo DSC 822. The GC–MS analyses were carried out on Thermo Finnigan Trace DSQ GC/MS-System with THF as solvent. HPLC analyses were performed on BioTek Konton 525 equipped with UV detector (at 260 nm, diode array detector HPLC 540) at room temperature (column: Chiralcel OD-H, eluent: methanol

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• -rotaxane sample, which hints at a different content of threaded TMS-β-CD or TMS-γ-CD on the copolymer chains (Table 1). The thermal properties of the copolymers were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results are summarized in Table 1. 4a and 4b

• . Moreover, the decomposition temperature at 5% weight loss for TMS-γ-CD determined by TGA analysis is around 390 °C [32]. The DSC curves of the polyrotaxane samples showed glass-transitions temperature (Figure 5). The Tg values increase from 91 °C for 4 to 128 °C and 105 °C for 4a and 4b, respectively. The

• DSC results suggest that the encapsulation of molecule 1 into TMS-β-CD and TMS-γ-CD cavities leads to more rigid copolymer structures with an increased Tg (Table 1). It should be pointed out that the higher molecular weight of 4a and 4b copolymers can also influence the phase transition temperature

Influence of cyclodextrin on the UCST- and LCST-behavior of poly(2-methacrylamido-caprolactam)-co-(N,N-dimethylacrylamide)

• Alexander Burkhart and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 1951–1958, doi:10.3762/bjoc.10.203

• measured at room temperature. FTIR spectra were recorded on a Nicolet 6700 FTIR spectrometer equipped with an ATR unit. Differential scanning calorimetry (DSC) was performed using a Mettler Toledo DSC 822 instrument equipped with a sample robot TSO801RO. For calibration, standard tin, indium, and zinc

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• using a Waters Millennium apparatus with polystyrene standards. The Tg data were determined from a second heating at a heating rate of 10 °C/min by differential scanning calorimetry (DSC) using a Thermal Analysis Q10 instrument. Typical procedure for PO/PA alternating copolymerizations. A bomb reactor

• removed using a rotary evaporator, and the residual solvent was removed completely by keeping the isolated lump in a vacuum oven overnight at 100 °C. When the PA conversion was not 100%, the polymer was obtained admixed with unreacted PA. For DSC studies, small pieces of the polymer lump admixed with the

• )CH2-carbonate; "c" signal for ester-CH2CH(Me)-carbonate; "d" signal for carbonate-CH2CH(Me)-carbonate; "*" signals for propylene carbonate; "#" signals for unreacted PA). GPC curves of the PO/PA copolymers. DSC curves of PO/PA alternating polymer (A, entry 1 in Table 1), PO/CO2/PA terpolymer (B, entry

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