The conformations of 9,9-di(9-fluorenyl)fluorene derivatives (1) with substituents at the 2- or 2,7-positions in a terminal fluorene ring were illustrated by the gauche-gauche forms at room temperature. DNMR studies of 1 gave the values of about 85–88 kJ/mol for the free energy of activation (ΔG\eweq) for the restricted rotation around the C(9)–C(9) bonds. The conformation of 9,9-di(9-fluorenyl) fluorene
125. Aromatic reactivity. Part XXVII. Substituent effects in biphenyl and fluorene
作者:R. Baker、R. W. Bott、C. Eaborn、P. M. Greasley
DOI:10.1039/jr9640000627
日期:——
A facile approach to the synthesis of substituted dibenzofulvenes-precursors to pi-stacked poly(dibenzofulvene)s
作者:Michael Y. Wong、Louis M. Leung
DOI:10.1016/j.tet.2010.03.046
日期:2010.5
A series of novel substituted (2-methoxy, 2-nitro, 2-bromo, 2-iodo, 2-cyano, and 2-acetyl) and di-substitiuted (2-bromo-7-methoxy, 2-bromo-7-propoxy, 2-bromo-7-hexoxy, 2-nitro-7-propoxy, 2-nitro-7-hexoxy, and 2,7-di-bromo) dibenzofulvenes have been prepared from the corresponding fluorenes with fair to very good overall yields (35.7-66.7%) based on the Wittig chemistry. The new approach enjoyed much simpler experimental procedures and has the advantage of higher functional group tolerance. Preliminary results on their polymerization using solution free-radical approach are also presented. (C) 2010 Elsevier Ltd. All rights reserved.