218-19-9

Upstream product

• 861047-40-7 3-chloro-11,12-dihydro-naphtho[1,2-h]quinoline 
• 4176-53-8 1-aminophenanthrene 
• 56-81-5 glycerol 
• 58794-11-9 cis-1-(1-naphthyl)-2-(3-pyridyl)-ethylene 
• 53500-08-6 trans-1-(1-naphthyl)-2-(3-pyridyl)-ethylene 
• 7664-93-9 sulfuric acid 
• 98-95-3 nitrobenzene 
• 121611-57-2 (E)-8-(2-phenylethenyl)quinoline 
• 132401-59-3 trans-8-styrylquinoline 
• 412036-73-8 11,12-dihydro-naphtho[1,2-h]quinolin-3-ol 
• 59292-69-2 1-Oxo-2-hydroxymethylen-1,2,3,4-tetrahydrophenanthren 
• 858434-51-2 3-hydroxy-11,12-dihydro-naphtho[1,2-h]quinoline-2-carboxylic acid 
• 412036-85-2 3-hydroxy-11,12-dihydro-naphtho[1,2-h]quinoline-2-carbonitrile 

Relevant academic research and scientific papers

Adiabatic trans-cis photoisomerization and photocyclization of 8-styrylquinoline

Kinetics of the photocyclization of trans-8-styrylquinoline into 10a,10b-dihydronaphtho[1,2-h]quinoline (4-azachrysene) was studied in hexane. It was found that in addition to the expected two-step (two-quantum) route with trans-cis photoisomerization occurring in the first step with a quantum yield of Φtc = 0.13 with consequent photocyclization of the cis-isomer with a quantum yield of 0.23. The direct singlequantum photocyclization of the trans-isomer with a quantum yield of 0.009 is also observed. The latter observation indicates that the excited trans-isomer isomerizes without loss of excitation to the excited cis-isomer, which then undergoes cyclization, i.e., the trans-cis photoisomerization proceeds partially by adiabatic mechanism t* → c*.

The photochemical cyclodehydrogenation route to polycyclic azaarenes

This paper reports an investigation of photochemical cyclodehydrogenation for the preparation of polycyclic azaarenes. Various naphthoquinolines and naphthoisoquinolines were obtained from 2-, 3-, and 4-[2-(1- and 2-naphthyl)vinyl]pyridine. 4-[2-(3-Phenanthryl)vinyl]pyridine gave pyreno[1,10-hij]isoquinoline. An efficient preparation of (2-arylvinyl)pyridines is described. Georg Thieme Verlag Stuttgart.

PHOTOCHEMISTRY AND LUMINESCENCE OF ROTATIONAL ISOMERS OF 1-(n-NAPHTHYL)-2-(3-PYRIDYL)ETHYLENE

The trans isomers of 1-(n-naphthyl)-2-(3-pyridyl)ethylene (n,3-NPE, with n=1 or 2) exibit some anomalies in their fluorescence behaviour.The fluorescence spectrum and quantum yield of 2,3-NPE at room temperature show a dependence on the excitation wavelength (λex) and the fluorescence decay follows a bi-exponential function.For 1,3-NPE, only the fluorescence spectrum in a rigid matrix depends on λex whilst ΦF changes only slightly and the observed decay is monoexponential.This behaviour, which can be accompained by a λex-dependent photochemistry, is probably due to the existence in solution of distinct rotational isomers involving the quasi-single bonds between the aromatic groups and the ethylenic carbons.The almost isoenergetic naphthyl conformers are probably responsible for the more pronounced λex-effect on 2,3-NPE while the pyridyl conformers could give a greater contribution to the smaller effect observed in the less planar 1,3-NPE.The corresponding cis isomers give azabenzophenanthrenes as photocyclization products.In both cases, two products were isolated.Their very different chemical yields depend on the position of the heteroatom with respect to the photoreactive site.The fluorescent properties of the four cyclized products, including the effect of oxygen, were also determined.