Synthesis, structure and reactions of the first tellurium-containing macrocyclic Schiff base

Abstract

The condensation of bis(2-formylphenyl) telluride 1 with ethane-1,2-diamine yielded the novel macrocyclic tellurium ligand 2 via metal-free dimerisation. Crystals of 2 are triclinic, space group P1̅ with a=7.956(3), b=9.885(2), c=10.068(2)Å, Z=1. Hydrogenation of macrocycle 2 provided the corresponding saturated tetraazamacrocycle 3, protonation of which with HBr afforded 4. The co-ordination chemistry of 2 has been studied with 'soft' metal ions such as palladium(II) and mercury(II). N,N'-Bis[(2-chlorotelluranyl)benzylidene]ethane-1,2-diamine has also been characterised by an X-ray diffraction study, with triclinic space group P1̅, a=7.71(1), b=7.90(1), c=8.52(1)Å and Z=1.