Synthesis and Modulation of Bis(triazine) Hydrogen‐Bonding Receptors

Abstract The synthesis of bis(triazine) molecules capable of acting as synthetic receptors for barbiturate guest molecules is described. The binding properties are also reported illustrating the modulation of the binding properties of these species by the modification of the hydrogen‐bonding patterns of the receptor molecule, namely 1,3‐ N , N′ ‐bis[4‐(dibenzylamino)‐6‐(butylamino)‐1,3,5‐triazin‐2‐yl]xylylenediamine ( 1 ). Thus 1,3‐ O , O′ ‐bis[4‐(dibenzylamino)‐6‐(butylamino)‐1,3,5‐triazin‐2‐yl]benzenedimethanol ( 3 ) and 1,3‐ O , O′ ‐bis[4‐(dibenzylamino)‐6‐(diethylamino)‐1,3,5‐triazin‐2‐yl]benzenedimethanol ( 5 ) have been prepared, and their binding constants compared to those observed for 1 . In the case of compounds 3 and 5 the hydrogen‐bonding secondary amines at the apex of the receptor 1 are substituted by non‐hydrogen‐bonding ether links. The hydrogen‐bonding ability is further modified in the case of 5 by the removal of all hydrogen‐bond donors from the receptor site, replacing secondary amines by tertiary amines. NMR binding studies illustrate how these simple modifications of the hydrogen‐bonding patterns of these receptors influences the overall strength of binding demonstrating a simple mechanism for controlling host‐guest complex formation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)