Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• observed during the 1st and 2nd DSC heating and cooling scans. However, glass transitions were detected for all the studied compounds. The glass transition temperatures (Tg) fall in the range between 63 and 93 °C (Figure 5b). A correlation between the glass transition temperature and the molecular weight

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• scanning calorimetry (DSC) under N2 atmosphere at a scanning rate of 10 °C min−1. As displayed in Figure 5a, the compound has a high thermal stability with a decomposition temperature at 5% weight loss (T5d) of 498 °C, a glass transition temperature (Tg) of 236 °C, and a melting temperature (Tm) of 376 °C

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• material 4CzIPN, having a Td in the range of 402–449 °C (Td range is dependent on the type of the 4CzIPN polymorph) [11][12]. Differential scanning calorimetry (DSC) shows an endothermic process in the range of 237 to 265 °C which can be associated with the glass transition temperature (Tg) for the

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• Information File 1). The analyzed product exhibited a glass transition temperature (Tg) at 140 °C, and no melting point was observed by DSC (Figure S5b, Supporting Information File 1), pointing to an amorphous nature of the resulting material. Incubation of EtOx with DLG at 90 °C showed no new signals in the

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• transitions (see Figure 1). Both polymers feature a glass transition temperature (Tg) at −58 °C (P1) and −51 °C (P2), respectively. Furthermore, the polymers have an endothermic transition at 129 °C (P1) and 126 °C (P2). This transition is associated with the activation of the perylene domains, which was also

• = 18,200 g/mol, Mw = 35,100 g/mol, Ð = 1.92 (UV detector); Elemental analysis: found: C: 57.94, H: 7.97, N: 1.50; expected: C: 58.71, H: 8.21, N: 1.14. DSC-analysis of the polymers P1 and P2 (second heating and cooling cycle; 20 K/min for heating and cooling) with a glass transition temperature (Tg) at −58

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• absolute length of the block copolymer and the relative length of the blocks to each other and the glass transition temperature. If a block is composed of a thermoresponsive polymer, the amphiphilic character and self-assembly ability can be altered by changing the temperature. The thermoresponsive block

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• water and has a melting point of 250 °C and a glass transition temperature Tg of 76 °C [162][163]. It was suggested that under certain circumstances, PET may leach phthalates [164], which are known for potentially adverse health effects and subject to ECHA regulation restrictions [165][166]. Coupled

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• crystallized at 118 °C. When the sample was heated again, only a melting peak was observed at 186 °C. The Tg values observed for compounds 3–5 ranged from 79 to 97 °C, with the phenyl-substituted acridan 3 exhibiting the lowest glass-transition temperature. The higher Tg values can be explained by the higher

Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red

• Aydan Yadigarli,
• Qimeng Song,
• Sergey I. Druzhinin and
• Holger Schönherr

Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248

• polymer films, in which the values of the glass transition temperature (Tg) and segmental mobilities were found to be altered. Likewise, this holds for transport properties, including polymer nanocapsule membrane permeability [1], enzyme-triggered bacterial sensors [2][3][4][5] and intelligent self

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

• Feng-Ming Xie,
• Qingdong Ou,
• Qiang Zhang,
• Jiang-Kun Zhang,
• Guo-Liang Dai,
• Xin Zhao and
• Huai-Xin Wei

Beilstein J. Org. Chem. 2018, 14, 869–874, doi:10.3762/bjoc.14.73

• higher triplet energy level (2.80 eV) and a glass transition temperature (140 °C). The maximum external quantum efficiency (EQE) of PhOLEDs was 31.4%, which was prepared by PCPO as a bipolar host material. Kim et al. [17] reported that the bipolar host material 9-(4-(9H-pyrido[2,3-b]indol-9-yl)phenyl)-9H

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

• Lin Gan,
• Xianglong Li,
• Xinyi Cai,
• Kunkun Liu,
• Wei Li and
• Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

• , corresponding to a 5% weight loss) of 361 and 363 °C, respectively. In addition, no glass-transition temperature (Tg) was found according to their DSC curves. Thanks to their amorphous characteristics, the stability of their morphology and chemical composition can be expected during the evaporation processing

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• of a polymer at a temperature below its glass-transition temperature (Tg) due to the disruption of the polymer main chain [1]. Although most pulverization operations for a practical use are carried out at room temperature, electron spin resonance (ESR) spectroscopy analyses of mechanoradical

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

• proportional to the resting period and was accompanied by a constant increase in the glass-transition temperature. We hypothesize that a relaxation mechanism within the cross-linked scaffold, together with a long-lived stable ruthenium alkylidene species are responsible for the observed phenomenon. Keywords

• : glass-transition temperature; polydicyclopentadiene; ring opening metathesis polymerization; ruthenium-catalyzed olefin metathesis; thermoset polymers; Introduction Olefin metathesis [1][2][3][4][5][6] has advanced to become a major synthetic tool in academia [7][8][9][10][11] and industry [12

• of PDCPD obtained by ruthenium-induced ROMP of DCPD. Results and Discussion The observation of recurrent exothermic peaks in calorimetric analyses and a continuous rise in glass-transition temperature over time led us to study this phenomenon and propose a plausible mechanism for this behavior. When

Anion effect controlling the selectivity in the zinc-catalysed copolymerisation of CO₂ and cyclohexene oxide

• Sait Elmas,
• Muhammad Afzal Subhani,
• Walter Leitner and
• Thomas E. Müller

Beilstein J. Org. Chem. 2015, 11, 42–49, doi:10.3762/bjoc.11.7

• many of the physicochemical properties of the polymer, such as the glass-transition temperature (Tg). With incorporated ether linkages, a molecular weight in the oligomer range and at least two terminal OH groups, polyethercarbonates are interesting polyol building blocks in polyurethane chemistry [8

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

• orientation [17][18][19][20][21][22][23][24][25][26][27]. However, the brittleness of PLLA prevents drawing. To improve this, it is necessary to control the interchain interactions and lower the glass transition temperature (Tg) of the amorphous phase. Cyclodextrins (CDs) are cyclic molecules composed of six

Synthesis of graft polyrotaxane by simultaneous capping of backbone and grafting from rings of pseudo-polyrotaxane

• Kazuaki Kato,
• Katsunari Inoue,
• Masabumi Kudo and
• Kohzo Ito

Beilstein J. Org. Chem. 2014, 10, 2573–2579, doi:10.3762/bjoc.10.269

• the rotaxane structures [11]. GPRs with poly(ε-caprolactone) (PCL) as a flexible graft chain, which exhibits a much lower glass transition temperature than PMMA, have been cross-linked to yield flexible elastomers [11]. Such elastomers exhibit an excellent scratch resistance, and thus can be employed

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

• temperature (Tm) of the crystallized PEO segment and the glass transition temperature (Tg) of pure PHEMA, respectively. On the contrary, the curves of the PEP26MnCDs samples exhibit no obvious signal mutation from 20 to 80 °C. This indicates that either both PEO and PHEMA blocks stay amorphous or that the

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

• hydrogen-bond interactions in the relatively stiff homopolymer 6e the glass-transition temperature is higher than in the copolymers with various amounts of N,N-dimethylacrylamide (5). Conclusion It can be concluded from the above described results, that the novel copolymers from lysine based 2

• 4CD (a), Job plot of 2 with RAMEB-CD (b). Turbidity curves upon cooling of 10 mg ml−1 solution of copolymer 6a in various n-alcohols at a cooling rate of 1 °C min−1. Turbidity curves upon cooling of 10 mg ml−1 solution of polymer 6a and 6aCD at a cooling rate of 1 °C min−1 in ethanol. Glass-transition

• temperature as a function of the amount of N,N-dimethylacrylamide (5) in the copolymers 6a–i. Synthesis of monomer 2-methacrylamido-caprolactam (4) and copolymers 6a–i based on 4 and N,N-dimethylacrylamide (5). Monomer amount of 4 and 5 for the copolymerization of copolymers 6a–i. Different amounts of

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• groups that have thermodynamically favourable interactions with CO2; (d) low crystallinity; this can be decreased by increased branching structures on side chains and finally (e) a low glass transition temperature (Tg) [92]. There are also several factors that have been identified as having a negative

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

• -transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C). Keywords: carbon dioxide; CO2 chemistry; cobalt complex; phthalic anhydride; propylene oxide; terpolymerization; Introduction Carbon dioxide (CO2) can be utilized to prepare aliphatic polycarbonates through coupling reactions

• , 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (Mn up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (fPA, 0.23) showed a higher glass

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

• isosorbide, itaconic acid and succinic acid under acid catalyzed conditions (Scheme 5). The obtained unsaturated polyester 13 showed values of 3400 g/mol and a glass transition temperature of 64 °C. The cross-linking of 10a/b with 13 was investigated by rheological measurements in oscillatory mode. The

• and 200 °C with a heating rate of 10 °C·min−1. The glass transition temperature (Tg) values reported are taken from the third heating cycle. EIMS spectra were recorded on a GC–MS integrated system Trace DSG by Thermo Finnigan. The instrument was calibrated in the m/z range of 1050 Da. Synthesis of

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

• conversion. The resulting poly-adduct 9 exhibits a glass transition temperature (Tg) of around 49 °C. Equivalent measurements of standard BADGE demonstrated a gelpoint after about 99 min and a Tg of about 74 °C (Figure S4, Supporting Information File 1). Thus, the curing properties for a mixture of 6 with 8

• . 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

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

• transition temperature (Tg), swelling behavior and cloud points (Tc) were investigated. Redox-responsive behavior was further analyzed by rheological measurements. Keywords: cationic hydrogel; cross-linked polymer; 2-(dimethylamino)ethyl methacrylate (DMAEMA); disulfide cleavage; N,N-diethylacrylamide

• transition temperature (Tg), swelling behavior, and cloud points (Tc) of the thiol-bearing copolymers after cleavage were investigated. Although our results show only preliminary investigations, this hydrogel system with its redox-responsive behavior and polycationic structure could be a promising system for

• transition temperature Tg for samples 3–6. Cloud point temperatures Tc of poly(DEAAm-co-DMAEMA) bearing thiole side chains after disulfide cleavage with DTT in dist. H2O and pH 10 buffer solution. Supporting Information Supporting information features experimental procedures, descriptions of

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

• glass-transition temperature (Tg) of the methacrylic polymer 8 was found to be −40 °C, which is similar to the value that can be found in the literature [2]. Due to higher flexibility of the new acrylic polymer 9, a lower Tg of −50 °C was detected. According to DLS measurements, the addition of 1 equiv