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Photochemical Rearrangement of a 19‐Membered Azoxybenzocrown: Products and their Properties
Author(s) -
WagnerWysiecka Ewa,
Szulc Paulina,
Luboch Elżbieta,
Chojnacki Jarosław,
SzwarcKarabyka Katarzyna,
Łukasik Natalia,
Murawski Miłosz,
Kosno Michał
Publication year - 2020
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.202000474
Subject(s) - chemistry , tautomer , yield (engineering) , spectroscopy , ring (chemistry) , photochemistry , nuclear magnetic resonance spectroscopy , aldehyde , alkali metal , proton nmr , spectrophotometry , medicinal chemistry , stereochemistry , organic chemistry , catalysis , materials science , physics , quantum mechanics , metallurgy , chromatography
The preparation and characterization of products of the chemical and photochemical rearrangements of a 19‐membered o , o′ ‐azoxybenzocrown are presented. In photochemical rearrangement, besides the expected product i. e. 19‐membered o ‐hydroxy‐ o , o′ ‐azobenzocrown ( 19‐ o ‐OH) obtained under defined conditions with 75 % yield, also other macrocyclic products were isolated and identified, namely: 19‐membered p ‐hydroxy‐ o , o′ ‐azobenzocrown ( 19‐ p ‐OH) , 21‐membered o′ ‐hydroxy‐ o , p ′‐azobenzocrown ( 21‐ o′ ‐OH) and 19‐membered macrocycle containing a 5‐membered ring bearing an aldehyde group ( 19‐al) . The structures of two atypical products of the photochemical rearrangement – 21‐ o′ ‐OH and 19‐al – were determined in the solid state by X‐ray analysis and in solution using NMR spectroscopy. Tautomeric equilibrium of the formed hydroxyazobenzocrowns and its change depending on acidity/basicity of the environment and alkali and alkaline earth metal cations complexation were studied using UV‐Vis spectrophotometry, spectrofluorimetry and 1 H NMR spectroscopy.