“…For 5: UV/vis 438, 700, 765 nm; FAB MS (3-nitrobenzyl alcohol matrix) m/e (relative intensity) 639 (151Eu, 94), 641 (153Eu, 100). 4,5,9,24-Tetraethyl-10,16,17,23-tetramethyl-13,20,25,26,27-pentaazapentacyclo[20.2.1.131.1811.01419]heptacosa-3,5,8,10,12,14- (19),15,17,20,22,24-undecene (11). This macrocycle was prepared in ca.…”