Tacticity of poly(butyl-α-cyanoacrylate) chains in nanoparticles: NMR spectroscopy and DFT calculations

NMR spectroscopy and quantum chemical calculations were applied for structural characterization and determination of the preferred stereochemical sequence distribution of the monomer units in the homopolymer chains of poly(butyl-alpha-cyanoacrylate) nanoparticles. The stereochemical sequence distribution of the monomer units was defined by analysis of their high-resolution 1D H-1 and C-13 NMR and 2D J-resolved, H-1/C-13 HSQC and H-1/C-13 HMBC NMR spectra. The results were verified by employment of B3LYP/6-31G(d) calculations and are consistent with the preferred tendency of polymer chains of PBCN to adopt syndiotactic placements. The proton and carbon chemical shielding were calculated at BPW91/6-31+G(2d,p) level using the GIAO approach and B3LYP/6-31G(d) optimized geometry.