STRUCTURAL STUDIES OF SOME BINAPHTHYL DERIVATIVES. By N.Thorup, Department of Chemistry, Technical University of Denmark, DTU-207, DK-2800 Lyngby, Denmark, H.-J. Deussen and T. BjØrnholm, CISMI, Department of Chemistry, University of Copenhagen, Denmark and K.Bechgaard, Department of Solid State Physics, RisØ National Laboratory, Roskilde, Denmark and T.Geisler, Aalborg University, Aalborg, Denmark.

Crystal structures of several 1,1'-binaphthyl derivatives have been determined. In particular compounds which at the 2,2' positions have either identical ethoxy groups -O-C₂H₅ or a closed bridged ether -O-CH₂-O- and furthermore have identical substitution at the 6,6' positions. The latter groups may be Br, CHO, CN or H. As would be expected, the torsional angle of the central 1-1' bond varies considerably in the open forms whereas the torsion is rather restricted in the closed forms. Optically pure crystals as well as racemic crystals have been produced in some cases. Unfortunately, good quality crystals for structural studies are difficult to grow and, therefore, rather high residuals are generally obtained. Some of the compounds are potential candidates for nonlinear optical applications and in several cases measurements of second order activity have been made.