Characterization of 1:1 Random Copolymers Obtained from 6-, 7-, 11-, and 12-Carbon Amino Acids.
Abstract
15N-labelled N-substituted phthalimide derivatives were prepared from commercially available 15N-labelled potassium phthalimide and alkyl halides in dimethylformamide. The 15N CP/MAS and CSA NMR spectra were recorded for a series of labelled imides as well as a polyimide derived from thianthrene dianhydride and 4,4'-oxydinailine (ODA). The 15N CP/MAS results indicated that the 15N isotropic chemical shift is very sensitive to both hybridization. The 15N chemical shift anisotropy tensor elements (Delta 11, Delta 22, and Delta 33) for three labeled derivatives were determined from CSA lineshape analysis using the program POWFIT developed by Dr. Terry Oas. In addition, the tensor orientation for 15N-13C labelled N-methylphthalimide was obtained. It was determined from the CSA data that delta 33 lies approximately along the N-C bond axis, with Delta 22 assumed to be approximately perpendicular to the imide plane. The angles alpha and beta were found to be 90.380 and 7.01 deg, respectively. The dipolar coupling constant for 13C-15N bond was 882.95 Hz, corresponding to a bond length of 1.51A.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 22, 1993
- Accession Number
- ADA272059
Entities
People
- C. G. Johnson
- L. J. Mathias
Organizations
- University of Southern Mississippi