The reaction of sulfur with dilithio compounds. The syntheses and structures of phenanthro [1, 10‐cd]‐1,2‐dithiole and phenanthro[4,5‐cde] [1,2]dithiin

Abstract

Abstract The sequential reaction of selected polycyclic aromatic hydrocarbons with butyllithium/TMEDA/hexane and sulfur allows preparation of ring‐fused dithiins, dithioles, and thiophenes. In this manner, phenanthrene has been converted to phenanthro[4,5‐cde][1,2]dithiin and phenanthro[1,10cd]‐1,2‐dithiole. Yellow crystals of the dithiin form in C2/c (#15) space group with Z = 4, a = 13.537(3) Å, b = 8.933(2) Å, c = 9.601(4) Å, and β = 116.19 (2)°; while orange crystals of the dithiole form in P2 1 2 1 2 1 (#19) space group with Z = 4, a = 4.1507(5) Å, b = 14.436(3) Å, and c = 16.972(3) Å. Full structures have been determined for both compounds.