The two dimensional (1)H and (13)C NMR spectroscopy of styrene- methyl methacrylate copolymers.

We have observed the 500 MHz proton nmr spectra of random copolymers of styrene and methyl methacrylate and the 500 MHz proton spectrum and 125 MHz carbon-13 spectrum of a 1:1 alternating copolymer of these monomers. The spectra of the alternating copolymer are much simpler owing to the restriction of possible sequences and can be very fully interpreted in terms of stereochemical configuration and chain conformation. The carbon-13 spectrum shows that the ethyl aluminum sesquichloride catalyst produces a strictly alternating structure which, however, is entirely random with respect to stereochemical configuration.