Fig. 3: Characterizations of the tacticity of DHGs and PDHG-F backbones.

a The single-crystal crystallography of meso-DHG1 and rac-DHG1s. The blue lines exhibit the dihedral angles of the backbones. b The integral ratio of the vibrational absorption at 1248 ∼ 1264 cm⁻¹ band to 1024 cm⁻¹ band (I₁₂₄₈/I₁₀₂₄) and the intensity ratio of the 1294 cm⁻¹ band to 1024 cm⁻¹ band (I₁₂₉₄/I₁₀₂₄) for the specific mixing systems (meso-DHG1 and rac-DHG1). These results are extracted from the Fourier transform infrared spectra of mixing samples with well-defined doping percentage (transformed to de value of meso-selectivity). For example, 0% de = 1 : 1 of meso-DHG1 : rac-DHG1; full-rac represents the pure rac-DHG1 sample; full-meso represents the pure meso-DHG1 sample. The red dots exhibit the band intensity ratio of DHG1 mixing systems; the blue star shows the band intensity ratio of PDHG-F. c The ¹H NMR spectra of DHG1 (in black lines, as the end-capping units), DHG4 (in purple lines, as the repeat units), and PDHG-F (in red lines). The assignments of meso-DHG4 were made in reference to the ¹H–¹H correlation spectroscopy results. The key positions associated with the stereoselective calculation (such as c, i, and N8 sites) are marked in red.