High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: benz[l ]acephenanthrylene and benz[ j ]acephenanthrylene and their selective rearrangement to benzo[ j ]fluoranthene
High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: benz[l ]acephenanthrylene and benz[ j ]acephenanthrylene and their selective rearrangement to benzo[ j ]fluoranthene
High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: benz[l ]acephenanthrylene and benz[ j ]acephenanthrylene and their selective rearrangement to benzo[ j ]fluoranthene
作者:Martin Sarobe、Leonardus W. Jenneskens、Jolanda Wesseling、Ulfert E. Wiersum
DOI:10.1039/a607258e
日期:——
The novel C20H12 cyclopenta-fused polycyclic
aromatic hydrocarbon benz[l]acephenanthrylene (2) and
its isomer benz[j]acephenanthrylene (3) have
been obtained by flash vacuum thermolysis of
2-(1-chloroethenyl)benzo[c]phenanthrene (6) and
6-(1-chloroethenyl)chrysene (7), respectively. At
T 900
°C 2 and
T 1000
°C 3 rearrange selectively to the abundant combustion effluent
benzo[j]fluoranthene (1). No evidence for the presence
of the related rearrangement products
benz[l]aceanthrylene (12) and
benz[j]aceanthrylene (13), respectively, is found.
Semi-empirical AM1 calculations provide a rationalization for these
observations; the conversion of 2 and 3 into 1, instead of 12 and 13,
respectively, via consecutive
ring-contraction–ring-expansion processes and vice versa
is favoured.