STUDIES IN THE CYCLOPROPARENE SERIES - AN EXPERIMENTAL AND THEORETICAL INVESTIGATION OF POLAR DYES DERIVED FROM CYCLOPROPA[B]NAPHTHALENE

1H-Cyclopropa[b]naphthalene is converted into novel polar olefins 15-1 9 via reaction of the 1,1-disilyl with anthrone-like ketones. The alke nes so formed are crystalline, polar compounds that range in color fro m yellow to magenta. Solutions of the 10,10-dimethylanthrylidene 15, t he xanthenylidene 16, and N-methylacrydinylidene 18 fluoresce; parent anthrone 19 likely phosphoresces. X-ray crystal structure determinatio ns are reported for 15, 18, and the thioxanthenylidene 17. Theoretical studies using ab initio calculations at the HF/6-31G level have been performed to provide assessments of the structures, charge distributi ons, and dipole moments of 15-19.