High-resolution proton magnetic resonance spectra of fluorene and its derivatives—IV: The benzofluorenes

Abstract

High-resolution 1H NMR spectra are reported for dilute solutions of fluorene (I), benzo[ c]-(II), benzo[ b]-(III), and benzo[ a]fluorene (IV), and dibenzo[ a, g]fluorene (V). A full six-spin iterative analysis has been carried out on the 100 MHz aromatic spectrum of (I) in carbon tetrachloride solution. For (II) in carbon disulphide, tentative assignments from 220 MHz spectra, confirmed by 100 MHz decoupling experiments, enabled the 100 MHz spectrum decoupled from the dicyclic methylene to be analyzed iteratively as an AB and two uncoupled ABCD systems. Less complete spectral analyses have been made of (III) at 220 MHz in chloroform- d and at 100 MHz in carbon disulphide solution, of (IV) at 220 MHz m chloroform- d and at 100 MHz in carbon disulphide, and of (V) at 220 MHz in carbon disulphide solution.