Rosette formation by hydrogen bonding of 5,5-dialkylbarbituric acids with 2-amino-4,6-bis[5-(4'-aminophenyl)porphyrinatozinc]-1,3,5-triazines in solution

Porphyrin appended triazines (11a, 11b) and dialkylbarbituric acids (2a, 2b) were synthesised. The rosette formation by three-point intermolecular hydrogen-bonding interaction between substituted triazines and barbituric acid derivatives has been characterised in solution by UV-vis, IR, TGA-DTA and ESI-MS spectroscopy. The association constants of different combinations of host-guest moieties in equimolar quantities were determined by 1H NMR titration studies in CDCl3 at room temperature. The nature of substituents either on triazine or on barbituric acid were found to play a crucial role in rosette formation. [image omitted]Formation of a supramolecular multiporphyrin rosette consisting of three units each of substituted barbituric acids and substituted triazines in solution.