A new series of heteroaromatic receptors containing the 1,3-bis(6-oxopyridazin-1-yl)propane unit: their selective transport ability towards NH4+ in relation to Na+, K+ and Ca2+
摘要:
The synthesis of a new series of heteroaromatic macrocycles 6-9 containing the 1,3-bis(6-oxopyridazin-1-yl)propane and pyridine units is reported. The acyclic compounds 11-15 had to be prepared as the intermediates in the synthetic sequence. Evaluation of the ionophoric properties of 6-9 and 11-15 shows that 8 and 13 behave as good ammonium ion carriers and exhibit a high selectivity for ammonium with respect to spherically symmetric metallic ions like Na+, K+, and Ca2+. Molecular modelling of the ammonium complexes suggests that the host's oxyimino groups play a more relevant part in effective complexation than the pyridine unit, and that the high complexating efficiency of 13 might be related to the formation of a pseudocavity by intramolecular hydrogen bonding. (C) 2003 Elsevier Ltd. All rights reserved.
A new series of heteroaromatic receptors containing the 1,3-bis(6-oxopyridazin-1-yl)propane unit: their selective transport ability towards NH4+ in relation to Na+, K+ and Ca2+
摘要:
The synthesis of a new series of heteroaromatic macrocycles 6-9 containing the 1,3-bis(6-oxopyridazin-1-yl)propane and pyridine units is reported. The acyclic compounds 11-15 had to be prepared as the intermediates in the synthetic sequence. Evaluation of the ionophoric properties of 6-9 and 11-15 shows that 8 and 13 behave as good ammonium ion carriers and exhibit a high selectivity for ammonium with respect to spherically symmetric metallic ions like Na+, K+, and Ca2+. Molecular modelling of the ammonium complexes suggests that the host's oxyimino groups play a more relevant part in effective complexation than the pyridine unit, and that the high complexating efficiency of 13 might be related to the formation of a pseudocavity by intramolecular hydrogen bonding. (C) 2003 Elsevier Ltd. All rights reserved.
A new series of heteroaromatic receptors containing the 1,3-bis(6-oxopyridazin-1-yl)propane unit: their selective transport ability towards NH4+ in relation to Na+, K+ and Ca2+
The synthesis of a new series of heteroaromatic macrocycles 6-9 containing the 1,3-bis(6-oxopyridazin-1-yl)propane and pyridine units is reported. The acyclic compounds 11-15 had to be prepared as the intermediates in the synthetic sequence. Evaluation of the ionophoric properties of 6-9 and 11-15 shows that 8 and 13 behave as good ammonium ion carriers and exhibit a high selectivity for ammonium with respect to spherically symmetric metallic ions like Na+, K+, and Ca2+. Molecular modelling of the ammonium complexes suggests that the host's oxyimino groups play a more relevant part in effective complexation than the pyridine unit, and that the high complexating efficiency of 13 might be related to the formation of a pseudocavity by intramolecular hydrogen bonding. (C) 2003 Elsevier Ltd. All rights reserved.