Synthesis and Spectroscopic Studies of the Photochromism of Bifunctional Derivatives of Cymantrene in Solution and without Solvent.

Four monosubstituted cymantrene derivatives ( 5- 8) containing two functional groups (allyl and amide) in a dendritic substituent were synthesized. The irradiation of these compounds with an Hg lamp in solution and under solvent-free conditions gives two types of dicarbonyl chelates with Mn-olefin or Mn-amide coordination bonds. Olefin chelates ( 19 and 21) were isolated for the first time, and they undergo reverse photochemical intramolecular isomerization to the amide chelates in solution and as pure liquids. For the first time, it was shown that the photochromism of cymantrene functional derivatives can be observed without the use of a solvent. [ABSTRACT FROM AUTHOR]