2-Phenylnaphthalene derivatives

In general, for side chain liquid-crystalline polymers, macroscopic molecular alignment is not easy and therefore clear evidence of electronic charge carrier transport was confirmed first in liquid crystals with low molecular weight. In the 1990s, fast electronic conduction was verified in discotic columnar phases of triphenylene derivatives [79,80] and hexabenzocoronene derivatives [81,82] as well as smectic phases of 2-phenylbenzothiazole [83, 84] and 2-phenylnaphthalene derivatives [85], as shown in Fig. 14. Carrier... 

Fig. 22 Molecular structures of LC 2-phenylnaphthalene derivative and hexanediol di-acryalte...

There are few examples of natural 2-phenylnaphthalene derivatives. To our knowledge, the one natural 2-phenylnaphthalene derivative has been isolated from the Marine Sponge Jaspis sp. [12]. The authors postulated a biosynthesis from 3,4-dihydroxyphenylethanal, but C6-C3 derivatives, i.e., DOPA or 3,4-dihydroxyphenyllactic acid cannot be rejected considering the above discussion. 

F. 11 Impurity effect of teithiophene (6-TTP-6) on positive charge mobility in smectic and isotropic phases of 2-phenylnaphthalene derivative, 8-PNP-012. The inset shows transient photocurrents for positive carriCTs in Sm A phase pof non-doped 8-PNP-012 and doped 8-PNP-012 with 6-TTP-6 of 1 ppm and 50 ppm... 

Pig. 2.9 Transient photocurrents in the SmA phase of a 2-phenylnaphthalene derivative, undoped dotted line) and doped with 1 and 50 ppm of a teithiophene derivative solid line), o>, o> -dihexyl theithiophene... 

As described in the previous section, both electronic and ionic conductions take place in mesophases when the material contains trace amounts of chemical impurities. These types of conduction exhibit different charge carrier transport properties, as demonstrated by the transient photocurrents the different mesophases measured under the same conditions as shown in Fig. 2.10. In these transient photocurrents, the fast transit times are shifted to shorter times as the molecular order in the mesophases is increased from SmA to SmE and from Coin to the plastic phase, while the slow transits stay in the same time range of 1,000 (xs irrespective of the mesophase in both smectics and discotics. Figiue 2.11 shows Arrhenius plots of the mobilities for fast and slow transits of the 2-phenylnaphthalene derivative 8PNP-012. The mobility for the fast transit hardly depends on the temperature, while the mobility for the slow transit does depend on temperature, with an activation energy... 

Fig. 2.10 Electronic and ionic conduction for negative carriers in smectic mesophases of 2-phenylnaphthalene derivatives and in the columnar mesophases of triphenylene derivatives. The cell thickness and applied electric field are kept constant for each material...

Fig. 2.11 Arrhenius plot of carrier mobility for negative carriers in various phases of a 2-phenylnaphthalene derivative, 6-(4 -octylphenyl)-2-dodecyloxynaphthalene. Two transits, i.e., fast and slow transits are observed in the SmA and SmB phases the fast transit is attributed to electron transport and the slow one to anion transport the ionic mobility is enhanced by 5 mol%-dilution with dodecane, while electron mobility remains unchanged or is slightly decreased...

Zhang, H., Hanna, 1. High mu tau product in a smectic liquid crystalline photoconductor of a 2-phenylnaphthalene derivative. Appl. Phys. Lett. 85(22), 5251-5253 (2004)... 

Liquid crystal copolyesters were prepared using 4-phenylnaphthalene derivatives with 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, or other aromatic diacids. These materials display an improved balance of low melt viscosity, fast cycle time in molding, high tensile, low thermal expansion coefficient, and thermostability. 

The only approach to the synthesis of the natural arylnaphthalides has been the preparation of two fully methylated derivatives shown in Scheme XI (65). A 2,7-diarylpent-4-enenitrile (68) was cyclized to the phenyltetralin (69). Bromination and aromatization with N-bromosuccin-imide then gave the phenylnaphthalene derivative (70). Finally basic hydrolysis produced the phenylnaphthalide (71). 

Benzanthrone has been prepared by three general methods, the first of which is generally regarded as the best (i) by heating a reduction product of anthraquinone with sulfuric acid and glycerol,1 or with a derivative of glycerol, or with acrolein. The anthraquinone is usually reduced in sulfuric acid solution, just prior to the reaction, by means of aniline sulfate, iron, , or copper. It has also been prepared (2) by the action of aluminum or ferric chloride on phenyl-a-naphthyl ketone, and (3) from i-phenylnaphthalene-2-carboxylic acid. ... 

Reported relative rates ( hs/ hp,) are quite varied. As shown in Fig. 11, this ratio has been estimated to be from 1.5 (55) to as little as 0.13 (25) for some multiaromatic thiophene derivatives. Phenylnaphthalene was also reported to have a very different preference for the position of naphthalene ring hydrogenation in independent studies as compared to being an intermediate in the reaction matrix (56, 57). 

Fujianmycins A and B were isolated from a Streptomyces species (IA-CAS-114) in Fujian, China [167], The structure of fujianmycin A (34a) may be regarded as the 2,3-hydrated form of (33a), and fujianmycin B (34b) as its methyl ether derivative. The structure of antibiotic PD-116740 (35), isolated from an unidentified actinomycete species (WP-4669) and possessing activity against L1210 leukaemia in vitro and HCT-8 human colon adenocarcinoma cell line [168], may be visualized as the 3-hydroxylated 8-methyl-5,6-diol derivative of (33a). All these antibiotics contain the characteristic 2-phenylnaphthalene structural feature. 

In a related electron transfer reaction, phenylacetylene reacts to form a-phenylnaphthalene, most likely by 1,6-coupling of yet another 1,4-bifunctional intermediate. In addition, formation of a pyridine derivative (8) is observed. Apparently, the 1,4-bifunctional intermediate can be trapped also by the solvent acetonitrile [123],... 

Arylnaphthalenes. Arylnaphthalenes can be prepared by replacement of the amino group of naphthylamines by aryl groups. a-Phenyl-naphthalene can be prepared satisfactorily only through the stabilized diazonium salt method, but /3-phenylnaphthalene is obtained readily by several procedures. A considerable number of derivatives of /3-phenylnaphthalene have been prepared. An example is 5-nitro-6-methoxy-2-phenylnaphthalene (XII), which can be obtained in 19% yield from the nitromethoxy-/3-naphthylamine and benzene. From the reaction between diazotized /S-naphthylamine and nitrobenzene and sodium acetate, /S-(2-nitrophenyl)-naphthalene (XIII 14%) and /3-(4-nitrophenyl)-naphthalene (XIV 26%) are formed. 

Using the same procedure, phenyl-substituted alkenes can be aminated. For example, the photochemically promoted reaction of l,2-dihydro-4-phenylnaphthalene (3) with an amine in the presence of 1,4-dicyanobenzene (/ -DCNB) afforded the corresponding 2-amino-1 -phenyl derivatives 4, albeit in relatively low yield after 64-71% conversion of the alkene30. The stereochemistry of the product is dependent on the steric bulk of the amine, since the intermediate benzylic carbanion should undergo protonation from the less hindered face, that is, opposite to the amino group. The stereochemical assignment of 4 was based on chemical shifts and coupling constants for the methine protons in the H-NMR spectra. 

The shock against benzene produced H2, light alkanes from Ci to C3, light alkenes from C2 to C3, C2H2, and aromatic hydrocarbons witli molecular weights ranging from 102 (phenylacetylene) to 306 (quaterphenyl). Tliis reaction produced H2, CH4, polyphenyl compounds such as biphenyl, terphenyl, and quaterphenyl. Otlier major products were naphthalene, fluorene, trans-stilbene, phe-nanthrene, isomers of phenylnaphthalene and chrysene. The shock produced ethenyl in greater abundance than etliyl derivatives. 

Dimeric anhydrides. Brown and Stevenson found that phenylpropiolic acid derivatives are dimerized by DCC below 0° to derivatives of the anhydride of phenylnaphthalene-2,3-dicarboxylic acid. The reaction had previously been effected with acetic anhydride in phosphoryl chloride. 

The thermal iscmierisation in tetradecane of l-isocyano-2-phenylnaphthalenes to benzo[c]phenanthridine is accompanied by the 6-tetradecyl derivative formed by solvent participation. Irradiation of the isocyanide at 300 nm also produces the benz phenanthridine (J.H. Boyer and J.R. Patel. J. chem. Soc. Perkin I, 1979, 1070). 

Biradical 6, R = Ph, converts into benzo derivative of naphtho[l, 8-Z)c]pyridine (12), and 6, R = Me transforms depending on the reaction conditions and the presence of other reagents into l-methylamine-8-phenylnaphthalene (14), 1-methylideneamino-naphthalene (15), or / er/-fused azine (16). 

For application to thin film transistors (TFTs), which can operate electronic papers, high carrier mobility exceeding 0.01 cm2 V-1 s-1 is necessary. For this purpose, nematic semiconductors with low molecular order, resulting in relatively low carrier mobility, are not suitable. For application of thin films of semiconductors to TFTs, stabilization of the highly ordered smectic phases, which exhibit high carrier mobility, by photopolymerization may be desirable. Kreouzis et al. studied the carrier transport properties of photopolymer-izable phenylnaphthalene, diphenylbithiophene, and quaterthiophene derivatives having an oxetane moiety or l,4-pentadien-3-yloxy in their alkyl side chain (Fig. 21) [107,108],... 

More curiously, N-tosylated phenylalanine derivatives [10] and phenyllactic acid [11] can also be converted into 2-phenylnaphthalene in moderate yields whereas 3,4-dimethoxyphenyllactic acid treated with boron tribromide gives Kagan s ether in almost the same yield as 3,4-dimethoxyphenylethanal does [11]. In these cases, the decomposition of aryllactic acid or alanine derivatives may give arylethanal with the formation of water and carbon monoxide, Fig. (4). 

It is probably biosynthesised from an isoferulic acid derivative [21] and its 1-decarboxy derivative has previously been obtained from the same intermediate as that of salvianolic acid F [22,23], To date, attempts to synthetise it by a more straightforward strategy have failed. In order to obtain the correctly substituted 2-phenylnaphthalene skeleton, 2-bromo-... 

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