27063-48-5Relevant academic research and scientific papers
Discotic liquid crystals of transition metal complexes 58: Novel phthalocyanine-based mesogenic monomers and polymers exhibiting spontaneous homeotropic alignment and helical tetragonal columnar structure
Suzuki-Ichihara, Ayumi,Sugibayashi-Kajita, Makiko,Ariyoshi, Masahiro,Yasutake, Mikio,Ohta, Kazuchika
, p. 800 - 817 (2021/05/27)
Two synthetizations of a novel series of phthalocyanine-based discotic liquid crystals substituted by a polymerizable group, acryloyl group or a norbornene group: 2-(12-acryloyloxydodecyloxy)-3-methoxy-9,10,16,17,23,24-hexakis (3,4-dialkoxyphenoxy)phthalocyaninato copper(II) [abbreviated as (n,12)PcCu(OCH3)(Acryloyl) (7: e (n = 10), f (n = 12), g (n = 14))] and 2-(12-norborn-2-ene carbonyloxydodecyloxy)-3-methoxy-9,10,16,17,23,24-hexakis(3,4-dialkoxyphenoxy)-phthalocyaninato copper(II): [abbreviated as (n, 12)PcCu(OCH3)(Norb) (9e, f, g)]. Their liquid crystalline properties and homeotropic alignment were investigated using a polarizing microscope, a differential scanning calorimetry (DSC), and a temperature-variable X-ray diffractometer. As a result, each of the derivatives gave a Coltet mesophase in the higher temperature region, displaying perfect homeotropic alignment between the two glass plates. In order to obtain the thin film while keeping their homeotropic alignment at room temperature, attempts to polymerize the monomers, 7 and 9, in the Coltet phase showed homeotropic alignment. The polymerization of the acryloyl-substituted monomers (7) was not successful in any of the methods, whereas the polymerization of norbornene-substituted monomers (9) was quite successful by ring-opening metathesis polymerization with a Grubbs catalyst to obtain the novel polymers, poly-(n, 12)PcCu(OCH3)(Norb) (10e, f, g). Each of the polymers (10) were found to show a perfect homeotropic alignment from room temperature to ca. 200°C of the decomposition temperature. Moreover, it was also revealed from temperature-variable small-angle X-ray diffraction studies that each of the polymers 10 showed a helical Coltet (helical tetragonal columnar) structure. The helical Coltet phase structure may be able for use in organic electroluminescent devices and solar cells in the future.
Recyclable iron(ii) caffeine-derived ionic salt catalyst in the Diels-Alder reaction of cyclopentadiene and α,β-unsaturated: N -acyl-oxazolidinones in dimethyl carbonate
Meng, Di,Li, Dazhi,Ollevier, Thierry
, p. 21956 - 21963 (2019/07/30)
Iron(ii) triflate was used in combination with caffeine-derived salts as recyclable catalysts for the Diels-Alder reaction run in dimethyl carbonate (DMC) as a green solvent. The catalyst was prepared as an ionic salt from a xanthinium salt and Fe(OTf)2. Various substrates including α,β-unsaturated carbonyl and N-acyloxazolidinone derivatives were reacted with cyclopentadiene using this recyclable catalyst. The use of a low catalyst loading (1 mol%) afforded high yields (up to 99%) of the corresponding cycloadducts. The recycling and the efficiency of the catalyst were demonstrated for several runs.
Synthesis of Bicyclic Isocyanates and Bioisosteric 1,3-Disubstituted Ureas as Soluble Epoxide Hydrolase Inhibitors
Burmistrov,D’yachenko,Rasskazova,Butov
, p. 1166 - 1176 (2019/10/19)
(1S)-1-Isocyanato-4,7,7-trimethyl-2-oxabicyclo[2.2.1]heptan-3-one and 2-isocyanatobicyclo[2.2.1]-hept-5-ene were prepared by the Curtius rearragement reaction from the corresponding carboxylic acids. The synthesized isocyanates were used to synthesize, in high yields of 74–93%, bioisosteric 1,3-disubstituted ureas as potential human soluble epoxide hydrolase inhibitors.
Visible Light-Mediated Decarboxylative Alkylation of Pharmaceutically Relevant Heterocycles
Sun, Alexandra C.,McClain, Edward J.,Beatty, Joel W.,Stephenson, Corey R. J.
supporting information, p. 3487 - 3490 (2018/06/26)
A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.
Dye functionalized-ROMP based terpolymers for the use as a light up-converting material: Via triplet-triplet annihilation
Hollauf,Zach,Borisov,Müller,Beichel,Tscherner,K?stler,Hartmann,Knall,Trimmel
, p. 7535 - 7545 (2017/08/16)
In this paper we introduce and compare different terpolymers comprising covalently attached sensitizer and emitter chromophores for the use as a light up-converting material via triplet-triplet annihilation (TTA). Using the advantages of ring opening metathesis polymerisation it was possible to prepare five different polymer architectures in order to investigate the influence of polymer architecture and chromophore arrangement on the photon up-conversion behaviour. First, two new monomers containing the chromophores have been synthesized and characterized in regard to their photophysical characteristics suitable for triplet-triplet annihilation dye pair. For this purpose, a derivative of Pt(ii) meso-tetraphenyltetra(tert-butyl)benzoporphyrin as sensitizer and a perylenediester as emitter were attached to norbornene moieties via ester linkages. Polymerisations of these monomeric chromophores were performed in combination with dimethyl 5-norbornene-2,3-dicarboxylate as matrix monomer. Depending on the location of the dye molecules on the polymer chain, large differences in the TTA efficiency were observed. The best quantum yields have been achieved with a completely statistically distributed terpolymer showing an up-conversion quantum yield of up to 3% in solution.
Biorenewable ROMP-based thermosetting copolymers from functionalized castor oil derivative with various cross-linking agents
Ding, Rui,Xia, Ying,Mauldin, Timothy C.,Kessler, Michael R.
, p. 5718 - 5726 (2014/12/11)
A new norbornenyl-functionalized castor oil alcohol (NCA) was synthesized and ring-opening metathesis copolymerized separately with two norbornene-based cross-linking agents: dicyclopentadiene (DCPD) and a bifunctional norbornene crosslinker (CL). Isothermal differential scanning calorimetry (DSC) was used to examine the cure behavior of NCA/DCPD and NCA/CL resins, through which a reasonable cure schedule was determined. The glass transition temperature (Tg) and storage modulus (E′), characterized by dynamic mechanical analysis (DMA), increased significantly in both copolymer systems with the addition of cross-linking agents. Cross-link density of the two systems was evaluated using a modified empirical equation from the kinetic theory of rubber elasticity. Differences in tensile stress-strain behavior and thermal stability between polymerized NCA/DCPD and NCA/CL were correlated to the structural rigidity and cross-linking density resulting from the cross-linking agents.
Photo-initiated thiol-ene "click" hydrogels from RAFT-synthesized poly(N-isopropylacrylamide)
Ooi, Huey Wen,Jack, Kevin S.,Whittaker, Andrew K.,Peng, Hui
, p. 4626 - 4636 (2013/10/21)
Despite the efficiency and robustness of the widely used copper-catalyzed 1,3-dipolar cycloaddition reaction, the use of copper as a catalyst is often not attractive, particularly for materials intended for biological systems. The use of photo-initiated thiol-ene as an alternative "click" reaction to synthesize "model networks" is investigated here. Poly(N- isopropylacrylamide) precursors were synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization and were designed to have trithiocarbonate moieties as end groups. This structure design provides opportunity for subsequent end-group modifications in preparation for thiol-ene "click." Two reaction routes have been proposed and studied to yield thiol and ene moieties. The advantages and disadvantages of each reaction path were investigated to propose a simple but efficient route to prepare copper-free "click" hydrogels.
Rheokinetics of ring-opening metathesis polymerization of bio-based castor oil thermoset
Madbouly, Samy A.,Xia, Ying,Kessler, Michael R.
, p. 7729 - 7739,11 (2020/09/15)
Ring-opening metathesis polymerization (ROMP) of norbornenyl-functionalized castor oil has been evaluated using small-amplitude oscillatory shear flow experiments as a function of angular frequency, temperature, and curing time. At the onset temperature of the curing process, an abrupt increase in dynamic shear moduli, G and G″, and complex shear viscosity, ν*, was observed during the dynamic temperature ramps (2 °C/min heating rate) of the sample over a wide range of angular frequencies. A dramatic increase in zero-shear viscosity, ν0, was also observed at the gelation temperature, Tgel. The value of Tgel obtained from the abrupt increase in ν0 was found to be in good agreement with the value evaluated from the crossover point of G and G″. The real time curing kinetics was investigated under isothermal conditions over a wide range of angular frequencies at different constant curing temperatures (40, 45, 50, and 55 °C). The isothermal gelation kinetics was found to be strongly curing temperature dependent; i.e., the higher the curing temperature, the faster the gelation process. Both G and G″ showed a power law relationship with angular frequency at the gel point, with critical power law exponents at the gel point in good agreement with the value predicted using percolation theory. Furthermore, ν0 and the equilibrium storage modulus, G eq, were found to be well described by power law scaling functions with the relative distance from the gel point. The molecular dynamics and thermal stability of the fully cured sample were also investigated by dynamic mechanical analysis and thermogravimetry, respectively.
Characterization of large molecular weight ester-functionalized norbornene and hydroxylated norbornane carboxylic acid polymers prepared by ring-opening metathesis polymerization
Stidham, Sarah E.,Weinberg, Benjamin H.,Grinstaff, Mark W.
, p. 5185 - 5190 (2013/01/15)
5-Norbornene-2-ethyl ester (mixture of endo and exo) is polymerized via ring-opening metathesis polymerization, yielding polymers with molecular weights ranging from 50,000 to 5,000,000 g/mol. The polymers are hydroxylated and saponified without alteration of the molecular weight. The polymers are analyzed by NMR, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. Films are cast from the polymers at several molecular weights and their rheological properties are investigated. The results showed greater solid-like character with increasing molecular weight for all polymers analyzed. Cell viability studies showed that the films possessed minimal cytotoxicity.
Rapid photoassisted access to N,O,S-polyheterocycles with benzoazocine and hydroquinoline cores: Intramolecular cycloadditions of photogenerated azaxylylenes
Mukhina, Olga A.,Bhuvan Kumar,Arisco, Teresa M.,Valiulin, Roman A.,Metzel, Greg A.,Kutateladze, Andrei G.
supporting information; experimental part, p. 9423 - 9428 (2011/11/06)
Ring the changes: A new photoassisted approach to give conformationally constrained N,O,S-polyheterocyclic scaffolds of unprecedented topologies was achieved by intramolecular [4+4] and [4+2] cycloadditions of photogenerated o-azaxylylenes (23 examples; see scheme). The precursors can be readily assembled by simple and high-yielding reactions, thus making this a powerful synthetic method amenable to high-throughput diversity-oriented synthesis.
