thiophene oligomer

 Dear Netters,
 As I am involved in study of the optical properties of the oligomers of
 thiophene and phenyl, I would like to ask a question about the heptamer
 (n=7) of oligothiophene.  Can anyone provide me (a literature reference is
 ok) with information on the geometry of this molecule in the following
 situations :
                 1) isolated molecule
                 2) molecule in 1-propanol (at different temperatures)
                 3) molecule in a nonpolar solvent
                 4) molecule in in PMMA (solid state)
 Thanking you in advance, I will be glad to provide a summary to the list.
 Yours sincerely,
 Yves Verbandt                               tel. 32-2-641.36.13
 Applied Physics Dept.                       fax.          34.50
 Vrije Universiteit Brussel                  email yverband -AatT-
 Pleinlaan 2, 1050 Brussel, BELGIUM                yverband -AatT-