{'fraction_non_alphanumeric': 0.03488372093023256, 'fraction_numerical': 0.005813953488372093, 'mean_word_length': 5.557142857142857, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Spectral assignment and proton transfer studies of N‐(R‐salicylidene)‐1‐amino‐1‐deoxy‐ d‐sorbitols

Schiff bases (1–9), derivatives of various o-hydroxyaldehydes and 1-amino-1-deoxy-D-sorbitol, are optically active compounds that can be studied as potential ligands for various metal complexes. The properties of the Schiff base complexes and especially their use as enantioselective catalysts are related to the structure of the ligands; therefore, the knowledge about factors crucial for structure of ligands like hydrogen bond and proton transfer processes can be important for the possible applications of studied compounds. In this report, we present studies concerning intramolecular hydrogen bonding and tautomeric equilibrium as well as full assignment of H and C NMR spectra and N NMR data of N-(R-salicylidene)-1-amino-1-deoxy-D-sorbitols, which can be useful in synthesis of various optically active metal complexes or chiral N-acyloxazolines. Schiff bases, derivatives of natural product like D-sorbitol, can be especially useful in synthesis of new chiral complexes because of the presence of carbon chain with several hydroxyl groups and possible formation of polydentate complexes. Additionally, recent studies concerning Schiff bases, derivatives of glucosamine, and their complexes deal usually with ring form of glucose moiety, only few deal with chain form.