2.6- Bis- 5-phenyl-l,3,4-oxadiazol

When part of an extended conjugated system, 2,5-disubstituted-l,3,4-oxadiazoles often fluoresce. This makes them potentially useful as laser dyes, optical brighteners, and scintillators. For example, oxadiazole (121a) <84GEP(O)3245202> and l,4-bis-(5-phenyl-l,3,4-oxadiazol-2-yl)naphthalene... 

The crystal structures of 5-methyl-5-(2-methylprop-l-enyl)-2-phenyl-4-(4-phenylthiazol-2-yl)-A -1,3,4-oxadiazoline <90ZC26> and the rubidium and silver salts of 2-phenyl-A -l,3,4-oxadiazolin-5-one <85JOC4461> have been analyzed. A crystal study of bis-[2-(5-phenyl-l,3,4-oxadiazol-2-yl)-methyl] ether produced bond lengths and angles and showed the rings to be nearly coplanar <87AX(C)2166>. 

Finally, dianils of aromatic dialdehydes may react with 2 moles of a p-tolyl-substituted heterocycle. For example, 5-phenyl-2-(p-tolyl)-1,3,4-oxadiazole (71) reacts with Schiff s base from 2 moles of p-chloroaniline and 4,4 -diformylbiphenyl (72) to give 4,4 -bis[4-(5-phenyl-l,3,4-oxadiazol-2-yl)styryl]biphenyl (73).43 Along with further p-tolyl-substituted heteroaromatics, a number of carbocyclic aromatics have... 

Both the square planar bis(acetylacetonato)manganese(II) and the octahedral tris(acetyl-acetonato)manganese(III) have been shown to possess marked fungicidal activity in the protection of cotton and linen.49 Recently, the complex of manganese(II) with 4-(5 -phenyl-l, 3, 4 -oxadiazol-2 -yl)thiosemicarbazide (14) has also been shown to exhibit fungicidal properties.50 The structure of this bis-complex also appears to be unknown at present. 

Z)-(2-Aminothiazol-4-yl)methoxyimino acetic acid Bis-(2-oxo-oxazolidinyl)phosphinic chloride 2-Mercapto-5-phenyl-l,3,4-oxadiazole... 

Some of the previously illustrated fluorinated 1,3.4-oxadiazoles, such as 57 (Rp=CF3, C3F7) and 65 (R=C3F7 n=3), can be alternatively obtained by the Huisgen reaction approach [41], Both 5-perfluoroalkyl-2-phenyl-l,3.4-oxadiazoles 76 and the dihet-erocychc compound l,3-bis(2-phenyl-l,3,4-oxadiazol-5- yl)hexafluoropropane 78 (n=3) can be obtained by reaction of 5-phenyltetrazole 77 with perfluoroacyl chloride or perfluoroglutaryl chloride respectively (Scheme 22) [10],... 

Dipicryl-l,3,4-oxadiazole has been described as an initiating explosive, 2,5-dimethyl-l,3,4-oxadiazole has been used to extract aromatic hydrocarbons from mixtures with alkanes. The use of 4,4 -carbonyl-bis(2-phenyl-5-oxo-l,3,4-oxadiazole) as a blowing agent for foaming thermoplastic compositions (e.g., polycarbonates) has been described < 1996CHEC-II(4)268>. 

Zu erwahnen ist die Acylierung von 2-Phenyl-l,3,4-oxadiazol mit 2-Chlorcarbonyl-furan. Sie licfert in geringen Ausbeutcn 5-(2-Furoyl)-2-phenyl-l,3.4-oxadiazol(, i1 (5% Schmp. 160 ) und Bis-[5-phenyi-1,3,4-oxadiazol-2-y ]-(2-furoyloxy)-(2-furyl)-methan (15% Schmp. 250°)611. 

A number of ferrocene-containing 1,3,4-oxadiazoIes have been prepared. The reaction of ferrocenecarboxhydrazide with triethyl orthoformate gave three products, the principal one being 2-ferro-cenyl-l,3,4-oxadiazole (126 R = H). 76 2-Phenyl-5-ferrocenyl-l,3,4-oxadiazole (126 R = CgH5) and 2,5-diferrocenyl-l,3,4-oxadiazole (126 R = ferrocenyl) were prepared from the appropriate 1,2-diacyl-hydrazines.117 A number of other ferrocenyloxadiazoles, including the bis compound 127, were prepared in a similar manner.117 The oxadi-... 

Tokuhisa et al. (1995) investigated electron transport in a series of oxadiazole derivatives doped into PC. The derivatives were 2-(4-biphenyl)-5-(4-/-butyl-phenyl)-l,3,4-oxadiazole (PBD), 2,5-bis(l-naphthyl)-l,3,4-oxadiazole (BND), 2,5-bis(3-methoxyphenyl)-l,3,4-oxadiazole (BMD), 2,5-bis(4-diphenylamino-phenyl)-l,3,4-oxadiazole (BAPD), and 2,5-bis(4-diphenylaminophenyl)-l,3,4-oxadiazole (BDD). Electron transport in these materials has been described in the preceding section. By the incorporation of a donor functionality (diethyl-amino or diphenylamino) into the oxadiazole skeleton, both hole and electron transport were observed. For BDD doped PC, jxn = 6.5x 10-8 cm2/Vs and Up = 9.8 x 10-8 cm2/Vs (the field was not specified). The work of Murray et al. (1996), Kaeding et al. (1996), and Tokuhisa et al. are the only references to... 

Scheme 22 The Acyl-Tetrazole Rearrangement Route in the synthesis of fluorinated 1,3,4-oxadiazoles 65, 5-perfluoroalkyl-2-phenyl-l,3,4-oxadiazoles 76 and 1,3-bis(2-phenyl-1,3,4-oxadiazol-5- yl)hexafluoropropane 78...

Untersuchungen dcr UV-Spektren von Phenyl-1,2,4-oxadiazolen zeigen, daO das Hetaren nur als eine konjugierte Doppelbindungseinheit angesehen werden kann und nicht als ein aro-matisches (4n + 2)-Huckelsystem12,30. 3,5-Bis-[perfluor-alkyl]-l, 2,4-oxadiazole haben kein Absorptionsmaximum oberhalb von 220 nm9. 

Borsenberger et al. (1996e) measured hole mobilities of a series of donor glasses N,N/-diphenyl-N,N,-(2-naphthyl)-(p-terphenyl)-4,4/,-diamine (NDNTP), N,N -dipheny l-N,N -(2-naphthy l)-( 1,1 -phenyl)-4, -diamine (NDNPD), 9,9-bis 4-[N-(4-tolyl)-N-(2-naphthyl)amino]phenyl fluorene (BTNAF), and 2,5-bis(4-diethylaminophenyl)-l,3,4-oxadiazole (OXD). For OXD, the photocurient transients were dispersive. Nonetheless, transit times could readily be determined from the intersection of the two linear regions of the transients. In all glasses, the field and temperature dependencies were described as lo u /3E 2 and -(T0IT)2. The results are summarized in Table 6. 

Conventionally, as organic material possessing a hole transfer capability, diamine derivatives, which include low molecule organic materials, such as aryl amine compounds are used. Examples are A,A -bis-(3-methyl-phenyl)-A,A -diphenylbenzidine (TPD), and macromolecule organic materials, such as PVK. As an electron transfer material, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-l,3,4-oxadiazole (PBD) is well known. However, polymers incorporating both functionalities have certain advantages. 

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