Palladium(ii) induced complete conformational enrichment of the syn isomer of N,N′-bis(4-pyridylformyl)piperazine

Abstract

In the solution state, an equimolar mixture of syn- and anti-conformations is present for the ligand N,N′-bis(4-pyridylformyl)piperazine, L. Combining L with cis-Pd(en)(NO₃)₂ resulted in the formation of metallomacrocycle cis-[Pd₂(en)₂(L)₂](NO₃)₄, 1, quantitatively. Coordinated L in complex 1 was found to exist exclusively in the syn-conformation. The equimolar mixture of syn- and anti-conformations was re-established by ethylenediamine induced demetallation of 1.