Abstract
Six polyphenyls, including four new compounds, 5', 5''-di (2-biphenylyl)-2, 2'''-diphenyl-m-quaterphenyl (3), 2, 5', 2''-triphenyl-m-terphenyl (4), 3, 5-di (2-biphenylyl)-o-terphenyl (5), and 5''-(3-biphenylyl)-m-quinquephenyl (6), were synthesized by the Ullmann coupling reaction of iodo compounds. Proton magnetic resonance spectral studies indicated that the characteristic spectral features of the polyphenyls containing 1, 3, 5-trisubstituted ring system (s) were fully compatible with their conformational aspects deduced from stereomodels. Ultraviolet spectral data indicated that the dihedral angle of the pivot bond of the branched ring in the polyphenyls in solution is very similar to that of biphenyl.
