7-DIMETHYLAMINOCYCLOPENTA[C]COUMARIN, IN 2 POLYMORPHIC FORMS

Polymorphism in aminocoumarins has been observed in only one other ins tance [Jasinski & Paight (1994). Acta Cryst. C50, 1928-1930]. This str ucture, C14H15NO2, represents the first reported observation of a nonc entrosymmetric moiety in an aminocoumarin laser-dye compound. These di fferences, as well as those observed in luminescence changes, may resu lt from the crystallization of C13 in an out-of-plane position in the cyclopenta[c] ring of polymorph (II). The crystal structures of both p olymorphs [(I) and (II)] are stabilized by van der Waals forces.