1.3.5- Triphenyl-2-pyrazoline

Oxidation of ketone phenylhydrazones generates a radical-cation centre on the nitrogen atom adjacent to the benzene ring. The radical-cation is delocalised by both the hydrazone group and the phenyl ring. Reactions of 1,3,5-triphenyl-A -pyazolines illustrate the properties of these radical-cations. Two one-electron waves are seen at a rotating disc electrode in acetonitrile and for 1,3.5-triphenyl-pyrazoline, Ey. = 0.82 and 1.68 V vs. see [33]. The delocalised radical-cation is... 

Peng AD, Xiao DB, Ma Y, Yang WS, Yao JN (2005) Tunable emission from doped l,3,5-triphenyl-2-pyrazoline organic nanoparticles. Adv Mater 17 2070-2073... 

Many examples of ring closures by oxidation of hydrazone derivatives have been reported. Anodic oxidation of chalcone72 phenylhydrazone (17) performed in CH3CN—LiCI04 at platinum, using controlled potential electrolysis, gave 1,3,5-triphenylpyrazole (15-40% yield) (18), 1,3,5-triphenyl-A2-pyrazoline (19), l,3,5-triphenyl-A2-pyrazolinium perchlorate, 4,4-bis[3,5-diphenyl-A2-pyrazolinyl-(l)]-biphenyl (20), the diperchlorate of 20, and 4,4 -bis-[3,5-diphenylpyrazolyl-(l)]-biphenyl (21) [Eq. (30)]. 

Bilgin AA, Palaska E, Sunal R, Guemuesel B (1994) Some l,3,5-triphenyl-2-pyrazolines with antidepressant activities. Pharmazie 49 67-69... 

Catechin 1 -Cyclohexyl-4-(4-arylcyclohexyl)piperazines 1 -d-Ribofuranosylbenzimidazole 1 -Naphthylisothiocyanate 1 -Phenyl-2-decanoylamino-3-morpholino-1-propanol l,2-Diarylimidazole-4-carboxamides l,3,5-Triphenyl-2-pyrazolines l,4-bis-[2-(3,5-Dichloropyridyloxy)]benzene (TCPOBOP) ... 

Synthesis of l,3,5-triphenyl-2-pyrazoline.lg A mixture of benzalacetophenone, acetic acid, and phenylhydrazine is heated at 90-100° for 2-3 hrs. and then let cool to room temperature. The product separates in small yellow crystals of satis-... 

The photo-oxidation of the commercially important l,3-diphenyl-2-pyrazolines has been further investigated,281- 282 and the photo-oxidation of 6,6-diarylfulvenes reported.283 Another polymer-bound singlet oxygen carrier has been used to simplify photo-oxidation reactions,284 and the decomposition of bis-(triphenyl-bromoantimonyl) peroxide provides another useful source of singlet oxygen.285... 

Technetium Color formation with 1,3,5-triphenyl-A -pyrazoline 0.01-12 Initial-rate and fixed-time methods used... 

Triphenyl-zl -pyrazoline electrolyzed in acetonitrile containing tetraethyl-ammonium perchlorate, pyridine added, and electrolysis continued until the current decreases to 1% of its initial strength 4,4 -biS (3,5 diphenylpyrazol-l-yl)biphenyl. Y 84%. F. e. s. F. Pragst, Z. Chem. 14, 236 (1974) oxidative dimerization also with FeClg (s. Synth. Meth. 3, 603) s. J. pr. 316, 195 (1974). 

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