62248-95-7

Basic information

• Product Name: Azacyclohepta-1,2,4,6-tetraene
• CAS NO: 62248-95-7
• Molecular Formula: C6H5N
• Molecular Weight: 91.1124
• Mol File: 62248-95-7.mol

Chemical Properties

• CAS DataBase Reference: Azacyclohepta-1,2,4,6-tetraene(CAS DataBase Reference)
• NIST Chemistry Reference: Azacyclohepta-1,2,4,6-tetraene(62248-95-7)
• EPA Substance Registry System: Azacyclohepta-1,2,4,6-tetraene(62248-95-7)

Safety Data

• Hazardous Substances Data: 62248-95-7(Hazardous Substances Data)

Upstream product

• 73876-43-4 N-phenylnitrilimine 
• 622-37-7 Phenyl azide 
• 3815-83-6 3,4-diphenylsydnone 
• 5378-52-9 phenyl-1H-tetrazole 
• 56476-95-0 2-phenyl-2H-tetrazole 
• 231289-36-4 C,N-Diphenylnitrilimine 

Relevant articles and documents

Photolysis and Pyrolysis of Phenyltetrazoles: Formation of Phenylcarbodiimide, N-Phenylnitrile Imine, Phenylnitrene, Indazole, and Fulvenallene

Photolysis of 1-phenyltetrazole 2b at either 193 or 266 nm in a Ne matrix as well as flash vacuum pyrolysis (FVP) of the same compound with isolation of the products in Ne matrix generate phenylcarbodiimide PhN=C=NH 6 very efficiently as the principal product in an almost pure state. Minor amounts of phenyl azide 8 and 1-azacyclohepta-1,2,4,6-tetraene 10, the product of ring expansion of phenylnitrene, are also formed, and the amounts of both substances increase as a function of photolysis time. The photolysis of 2-phenyltetrazole 1b in a Ne matrix at 266 nm for 0.5 min generates the allenic N-phenylnitrile imine PhN=N(+)=CH(–) 3b, absorbing strongly and cleanly at 2021 cm–1 in the IR spectrum. At longer photolysis times peaks ascribed to phenyl azide, phenylnitrene, 1-azacycloheptatetraene, and phenylcarbodiimide 6 become prominent. FVP of 2-phenyltetrazole yields indazole 15 as the major product together with a small amount of phenylcarbodiimide 6. Indazole formation is ascribed to cyclization of the nitrile imine in the ground state. It is not formed on FVP of 1-phenyltetrazole in agreement with the computational result that the thermodynamically most favourable path for rearrangement of the putative N-phenylimidoylnitrene 5b yields phenylcarbodiimide 6 rather than phenylnitrile imine 3b. Further pyrolysis of indazole affords a minor yield of fulvenallene 18.

Sydnone photochemistry: Direct observation of earl's bicyclic lactone valence isomers (oxadiazabicyclo[2.1.0] pentanones), formation of carbodiimides, reaction mechanism, and photochromism

The matrix photolyses of 3-phenyl-, 3-pyridyl, and 3,4-diphenylsydnones 16, 19, and 22 were investigated by matrixisolation infrared spectroscopy. The formation of the neutral, bicyclic lactone valence isomers postulated by Earl - the oxadiazabicyclo[2.1.0]pentanones exo-17 and exo-20 - was clearly observed in the first two cases and is also likely in the case of exo-23 (C=Oabsorptions in the IR at 1881, 1886, and 1874 cm -1, respectively). The efficient photodecomposition of sydnones to carbodiimides RN=C=NR0 (18, 21, and 24) and CO2 was established in all three cases. The formation of benzonitrile 27 and azacycloheptatetraene 29 in the matrix photolysis of diphenylsydnone 22 is indicative of diphenylnitrile imine PhCNNPh 26 as an intermediate (2340 cm -11). Neither bicyclic lactones nor carbodiimides have been observed previously in sydnone photochemistry. A general reaction mechanism for the formation of carbodiimides, nitrile imines, and photochromism is put forward. CSIRO 2014.