Benzocyclobutenoacenaphthylene stilbenes. 1. Synthesis and thermal properties

In this paper the synthesis and characterization of a new class of molecule s based an 6b,10b-dihydroobenzo[j]cyclobut[a]acenaphthylene (DBCA) with pot entially interesting optical and electronic properties are described. The m entioned compounds contain one or two DBCA units linked via a double bond t o an aromatic system. The synthesis of these compounds is mainly carried ou t by Heck and/or Wittig reactions. The introduction of DBCA units in molecu les is interesting in two respects: (1) It will influence the electronic an d optical properties of the compounds, and (2) it will induce dimerization (polymerization) because DBCA can, upon thermolysis or photolysis, be conve rted into a biradicaloid species ("pleiadene") which dimerizes. Thus suitab le compounds could be used as monomers for photochemically or thermally ind uced polymerization.