Ortho-rhom-bic polymorph of (2E)-2-(2,3-dihydro-1H-inden-1-yl-idene)-2,3-di-hydro-1H-inden-1-one.

ABSTRACT: The title compound, C(18)H(14)O, is polymorphic at 123?K. The ortho-rhom-bic form reported herein has two independent mol-ecules in the asymmetric unit, with mol-ecular volume 313.5?Å(3). The previously reported triclinic (P-1) form [Raston & Scott (2000 ?). Green Chem., 2, 49-52] has mol-ecular volume 309.6?Å(3) at the same temperature. All three mol-ecules deviate significantly and systematically from the putative C(s) symmetry (?(r.m.s.) = 0.0265, 0.0256, 0.0497?Å). Comparison of the two molecules in the orthorhombic polymorph shows that 16 of the 19 equivalent pairs of framework atoms have a mirror-image pattern of deviations (above/below plane), suggesting that the two are quasi-enanti-omorphs. The pattern of deviations in the triclinic form is nearly the same (13 of 19 atom pairs) as the ortho-rhom-bic form.

SUBMITTER: Li H 

PROVIDER: S-EPMC3435792 | biostudies-other | 2012 Sep

REPOSITORIES: biostudies-other