5731-01-1Relevant academic research and scientific papers
Pure Deep Blue Light-Emitting Diodes from Alternating Fluorene/Carbazole Copolymers by Using Suitable Hole-Blocking Materials
Lu, Jianping,Tao, Ye,D'iorio, Marie,Li, Yuning,Ding, Jianfu,Day, Michael
, p. 2442 - 2449 (2004)
The influences of the carbazole content on the photophysical, electrochemical, and electroluminescent properties of alternating fluorene/carbazole copolymers PFnCz (n = 1, 2, 3) with well-defined chemical structures have been systematically investigated. The incorporation of carbazole units into the polyfluorene (PF) backbone resulted in a blue shift of both the absorption and photoluminescence (PL) emission peaks, improved PL thermal stability, raised HOMO energy levels, and thus facilitated hole injection into the copolymers. Pure deep blue electroluminescence (EL) with narrow with (full width at the half-maximum) (39-52 nm) and negligible low-energy emission bands was successfully achieved from the PFnCz copolymers by using l,3,5-tris(4′-fluorobiphenyl-4-yl)benzene (F-TBB) as a hole-blocking layer and Alq3 as an electron injection/transporting layer. This device configuration stabilized the blue emission from the PF derivatives. An efficiency of 0.72 cd/A at a luminance of 100 cd/m2 was obtained even with aluminum metal as the cathode.
Synthesis of 4-Alkyl-2″, 3″ difluoro terphenyl nitrile using coupling reactions
Kayani, Zohra N.,Lewis, Robert A.,Naseem, Shahzad
, p. 72 - 84 (2012)
Study of chirality in liquid crystals is one of the most interesting areas of liquid crystal science. Liquid crystalline terphenyls with two lateral fluoro substituent and alkyl substituent in the 4- have been synthesised. Convergent approach was applied which involved the use of arylboronic acids and aryl halides in palladium-catalysed cross-coupling reactions. All the diifluoroterphenyls generate the smectic C phase. Mixture of 4-Alkyl-2″, 3difluoro terphenyl nitrile in achiral host mixture HM1 generates ferroelectric liquid crystal properties. Ferroelectric properties were found to be highly dependent upon the relative lengths of the alkyl chain attached to chiral dopant. The compounds were studied using optical polarisation microscopy, differential scanning calorimetric, nuclear magnetic resonance, and Instec elecro-optical device to find ferroelectric liquid crystal properties.
ABSOLUTE CONFIGURATION OF AN ALLENIC ENZYME INACTIVATOR
Schwab, John M.,Lin, Daniel C. T.,He, Cun-heng,Clardy, Jon
, p. 4909 - 4912 (1984)
X-Ray crystallographic analysis of the 4-(4'-bromophenyl)phenacyl ester of (+)-2,3-decadienoic acid has shown that the allenic inhibitor of β-hydroxy-decanoylthioester dehydrase has the S configuration.
Understanding the remarkable difference in liquid crystal behaviour between secondary and tertiary amides: The synthesis and characterisation of new benzanilide-based liquid crystal dimers
Strachan, Grant J.,Harrison, William T. A.,Storey, John M. D.,Imrie, Corrie T.
, p. 12600 - 12611 (2021/06/17)
A number of liquid crystal dimers have been synthesised and characterised containing secondary or tertiary (N-methyl) benzanilide-based mesogenic groups. The secondary amides all form nematic phases, and we present the first example of an amide to show the twist-bend nematic (NTB) phase. Only two of the correspondingN-methylated dimers formed a nematic phase and with greatly reduced nematic-isotropic transition temperatures. Characterisation using 2D ROESY NMR experiments, DFT geometry optimisation and X-ray diffraction reveal that there is a change in the preferred conformation of the benzanilide core on methylation, fromZtoE. The rotational barrier around the N-C(O) bond has been measured using variable temperature1H NMR spectroscopy. This dramatic change in shape accounts for the remarkable difference in liquid crystalline behaviour between these secondary and tertiary amide-based materials.
Visible light-driven Suzuki-Miyaura reaction by self-supported Pd nanocatalysts in the formation of Stille coupling-based photoactive microporous organic polymers
Ahn, Tae Kyu,Choi, Sung Jae,Jo, Bonghyun,Kim, Hae Jin,Ko, Kyoung Chul,Ko, Yoon-Joo,Lee, Sang Moon,Ryu, Sang Hyun,Seon, Ji Hui,Son, Seung Uk
, p. 5535 - 5543 (2020/09/17)
Stille coupling was applied to synthesize microporous organic polymers (MOPs). Metallic Pd was in situ self-supported during the networking of 1,3,6,8-tetrabromopyrene with 1,4-bis(tributylstannyl)benzene to form Stille coupling-based MOP (St-MOP)?Pd. The size of St-MOP particles and the amount of metallic Pd in St-MOP?Pd depended on the amount of Pd catalyst. As the amount of Pd catalyst increased, the size of St-MOP particles decreased with an increase of metallic Pd, due to the increased St-MOP nuclei in the early growth stage of St-MOP. The St-MOP bearing pyrenes showed absorption and emission of visible light and St-MOP?Pd showed excellent catalytic performance in the visible light-driven Suzuki-Miyaura coupling. The optimal St-MOP?Pd-2 (0.14 mol% Pd) showed a TON of 657 and a TOF of 219 h-1 in the visible light-driven Suzuki-Miyaura coupling of 1-acetyl-4-bromobenzene and phenylboronic acid at 25 °C. The optimal amount of St-MOP and metallic Pd in St-MOP?Pd was critical to achieve excellent catalytic performance. The overall photocatalytic principles of St-MOP?Pd were rationalized by computational simulation. This journal is
Carboncarbon bond forming reactions: Application of covalently anchored 2,4,6-triallyloxy-1,3,5-triazine (TAT) Pd(II) complex over modified surface of SBA-15 to Heck, Suzuki, Sonogashira and Hiyama cross coupling reactions
Singh, Chandani,Jawade, Kiran,Sharma, Priti,Singh, Anand P.,Kumar, Pradeep
, p. 11 - 15 (2015/06/08)
A highly active SBA-15-TAT-Pd(II) catalyst was synthesized from organofunctionalized SBA-15 and 2,4,6-triallyloxy-1,3,5-triazine. The catalyst was employed in carrying out Heck, "copper-free" Sonogashira, Suzuki and Hiyama cross coupling reactions. Under the optimized conditions the catalyst displays excellent catalytic activity in delivering the desired products in good to excellent yields. The catalytic system exhibited superior activity regarding the time taken for the completion of reaction, isolation, Pd loading (0.62 mmol%) and yields of products as compared to the earlier reported heterogeneous SBA-15 anchored Pd catalysts. The catalyst could be recycled and reused for five times without any appreciable loss of catalytic activity.
Palladium(II) complexes of 1,2,4-triazole-based N-heterocyclic carbenes: Synthesis, structure, and catalytic activity
Turek, Jan,Panov, Illia,Semler, Miloslav,Stepnicka, Petr,De Proft, Frank,Padelkova, Zdenka,Ruzicka, Ales
supporting information, p. 3108 - 3118 (2014/07/08)
Six palladium(II) complexes bearing three different triazole-based N-heterocyclic carbene (NHC) ligands, [1-tert-butyl-4-{2-[(N,N-dimethylamino) methyl]phenyl}-3-phenyl-1H-1,2,4-triazol-4-ium-5-ide, 1-tert-butyl-4-(2- methoxyphenyl)-3-phenyl-1H-1,2,4-triazol-4-ium-5-ide, and 1-tert-butyl-4-(4- methylphenyl)-3-phenyl-1H-1,2,4-triazol-4-ium-5-ide], were synthesized and fully characterized. NMR spectroscopy and X-ray diffraction analysis revealed that the amino-group-substituted NHC ligand is coordinated in bidentate fashion, forming a monocarbene chelate complex with an additional intramolecular Pd ← N bond with the nitrogen donor atom. The 4-methylphenyl- and 2-methoxyphenyl-substituted NHC ligands coordinate as C-monodentate donors, forming simple biscarbene Pd(II) complexes. The evaluation of the catalytic performance in the Suzuki-Miyaura cross-coupling reaction revealed very promising performance of the intramolecularly coordinated monocarbene complexes under relatively mild conditions even in direct comparison with the commercially available PEPPSI catalyst. In contrast, the biscarbene complexes proved inactive in this catalytic process. According to theoretical calculations (EDA and NOCV analysis), functionalization of the 1,2,4-triazole-based NHC with the 2-[(N,N-dimethylamino)methyl]phenyl group has a significant effect on the stability of the NHC-metal bond.
Nickel-catalyzed one-pot Suzuki-Miyaura cross-coupling of phenols and arylboronic acids mediated by N,N-ditosylaniline
Chen, Liangshun,Lang, Hongyue,Fang, Lei,Zhu, Mengyun,Liu, Jinqian,Yu, Jianjun,Wang, Limin
supporting information, p. 4953 - 4957 (2014/08/18)
An efficient method for the construction of two distinct C aryl-Caryl bonds through the Ni-catalyzed Suzuki-Miyaura cross-coupling of phenols with arylboronic acids has been developed. This reaction proceeds through the in situ tosylation of phenols by using N,N-ditosylaniline as the sulfonylating reagent, which is highly active, markedly stable, and easily prepared. The scope with respect to the coupling partners - phenols and boronic acids - is broad, and sensitive functional groups are tolerated. Phenols, especially those containing an unprotected amino group, which are generally problematic for coupling under conventional one-pot conditions, are also viable substrates in this transformation.
Cyanoalkyl difluoro-terphenyl-carboxylate chiral dopants
Kayani, Zohra N.,Lewis, Robert A.,Naseem, Shahzad
scheme or table, p. 11 - 19 (2012/08/13)
A liquid crystal like difluoroterphenyl chiral dopant was synthesized to match the dimensions of a host chiral dopant mixture. The melting point of the chiral dopants was decreased by increasing the length of the alkyl chain. The melting point of the chiral dopants also decreased when fluorine was on the same ring as the ester i.e. at 2″, 3″ position. These dopants were formulated with terphenyl host mixture and liquid crystal properties were assessed. New dopants, when added to the host mixture, maintain SmA1 but the SmC2 phase was reduced markedly. There was a decrease in spontaneous polarisation when fluorine was on the same ring as the ester i.e. at 2″, 3″ position. As the molecular weight of the chiral dopant increased (pentyl ↑ heptyl ↑ nonyl), spontaneous polarisation decreased.
HEPATITIS C VIRUS INHIBITORS
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Page/Page column 97-98, (2012/01/05)
The present invention relates to compounds of the formula (I) and pharmaceutically acceptable salts thereof; to compositions containing such compounds; and to the of such compounds as inhibitors of HCV replication.
