Complete Solution NMR Analysis of Three Oligoimine Model CompoundsLynne Spencer, William B. Euler*, Daniel D. Traficante, Misoo Kim, William Rosen, Mag. Reson. Chem., 1998, 36, 398-402. AbstractA series of three model compounds (monomer, dimer, and trimer analogues) for polyisocyanides has been synthesized and their solution NMR spectra characterized. Analysis of the monomer and dimer analogues leads to the conclusion that the most stable forms of these molecular systems are planar with the C-C bond in an s-trans conformation and the imine moieties in a Z conformation. In solution, the trimer analogue exhibits a preferred conformation that has a planar s-trans-diimine segment covalently attached to a magnetically isolated monoimine segment such that each segment is oriented at approximately 90° to one another. This latter observation gives significant insight into the preferred molecular structure to be expected for sterically unconstrained poly(N-phenyliminomethylene) in solution. |