DFT and X-ray studies on the nature of hydrogen bonding in 1,2-dibenzoyl-cyclopentadiene

1,2-diacylcyclopentadienes (DACP), which exist in their monoenol forms as 2-acyl-6-hydroxy fulvenes, are fairly strong acids. There has, however, been little systematic study of chemistry of DACP or their anions. The first reported on DACPs were prepared by condensation of nitromalonaldehyde with 1,4-diketones [1]. Subsequently, 1,2-diaroyl and 1,2-diacetylcyclopentadiene [2,3] have been prepared by acylation of the cyclopentadienide anion . Recently Tayyari et. al [4] studied theoretically the potential function governing the proton movement in the diformylcyclopentadiene system and confirmed the results of microwave study [2]. In these studies it has been shown that DFCP the potential function for proton transfer is a low barrier symmetric double minimum function.