Synthesis and characterization of a macrocycle containing different functional groups and its non-cyclic counterpart

摘要

The macrocycle 9-methyl-3, 6, 9, 12, 15, 22, 31-heptaaza-25, 28, 38, 41-tetraoxa-hexacyclo [31.2.2.~3,62.~17,208~22,31]-heptatertracontal, 17 , 18, 20, 33, 34-hexaene (L1) containing different functional groups and its non-cyclic counterpart bis-[piperazinyl-4-(4-carboxybenzyl)ethyl)] methylamine (L) were synthesized. The protonation behavior of both compounds, i.e. their basicity constants and protonation sequence, was investigated both by potentiometry (25 deg C, I=0.15 mol dm~-3, NaCl) and ~1H, ~13C NMR spectroscopy. The results obtained were log K_1=8.48(1), 8.73(1); log K_2=7.25(1), 8.20(1); log K_3=6.66(1), 6.93(1); log K_4=4.01(1), 6.29(1); ions such as Ga(III) than does L1. log K=15.5(1) for [GaL]~+ and 13.8(1) for [GaL1]~3+, respectively.