Thermal Interconversions of the C16H10 Cyclopenta-Fused Polycyclic Aromatic Hydrocarbons Fluoranthene, Acephenanthrylene and Aceanthrylene Revisited

✍ Scribed by Sarobe, Martin ;Jenneskens, Leonardus W. ;Wesseling, Jolanda ;Snoeijer, Judith D. ;Zwikker, Jan W.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 794 KB
• Volume: 1997
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199719970624

✦ Synopsis

Abstract

The thermal interconversion of the C~16~H~10~ cyclopenta‐fused polycyclic aromatic hydrocarbons (CP‐PAH) fluoranthene (1), acephenanthrylene (2) and aceanthrylene (3) has been studied using Flash Vacuum Thermolysis (FVT). In contrast to previously reported flow‐pyrolysis results, which gave the unexpected thermodynamic stability order 1 > 3 > 2, FVT temperature‐conversion data unequivocally show the expected order 1 > 2 > 3. These results are supported by independent FVT experiments with 9‐ethynylphenanthrene (4), 9‐ethynylanthracene (5) and 5‐(anthryl‐9′‐methylene)‐2,2‐dimethyl‐1,3‐dioxan‐4,6‐dione (6), which are precursors for acephenanthrylene (2) and aceanthrylene (3), respectively. The interpretation of the FVT results is corroborated by semiempirical AM1 calculations of the C~16~H~10~ potential energy surface.