12,13,25,26-Tetraaza-2,15-dithia[3.3]phenanthrolinophane. Synthesis, conformational study and complexation reactions

Abstract

12,13,25,26-Tetraaza-2,15-dithia[3.3]phenanthrolinophane 7 was prepared from a cyclization reaction of 2,9-bis(bromomethyl)phenanthroline 3. The syn isomer of 7 was kinetically favoured while the anti isomer was the thermodynamically more stable product isolated. The macrocycle 7 formed 1:1 complexes, namely 10 and 11, respectively, with zinc(II) and cadmium(II) ions. A tetragonal-pyrimidal configuration is proposed for these complexes. A comparison of the 1H NMR spectral data of 7, 10 and 11 suggests that the complexation results in a symmetrical structure through the four nitrogen donor atoms. The sulfur atoms in the bridges do not seem to coordinate strongly to the metal ions.