{'fraction_non_alphanumeric': 0.033936651583710405, 'fraction_numerical': 0.00904977375565611, 'mean_word_length': 5.23943661971831, '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}}
Cucurbiturils substituted on the methylene bridge.

Cucurbit[6]uril (CB[6]) with a substituent attached solely to one methylene bridge was prepared for the first time. The monosubstituted CB[6] undergoes self-assembly to form a cyclic tetramer in the solid state. The affinity of the monosubstituted CB[6] to a series of alkylammonium salts was measured revealing a minor effect of the substituent on the binding properties of the macrocycle.