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RESEARCH PRODUCT

2,2’Bipyrimidine: A Useful Tool in Designing Polynuclear Complexes of Controlled Nuclearity

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The versatility of a simple ligand such as 2,2’-bipyrimidine (bpym) which can adopt chelating and bis(chelating) coordination modes facilitates the preparation of both mononuclear and polynuclear complexes whose nuclearity can be controlled by playing with the metal to bpym molar ratio, the nature of the counterion and the presence of additional ligands. In this work, we summarize our results dealing with the preparation and the structural and magnetic characterization of complexes between first-row transition metal ions and bpym. Examples of orbital reversal and tunable exchange in bpym-containing copper(II) complexes are presented and discussed. The influence of the number of unpaired electrons on the exchange coupling is investigated by a systematic magneto-structural investigation, which is carried out on the dinuclear complexes of formula [M2(bpym)]4+ where M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II). A simple orbital model is used to analyze die efficiency of bridging bpym to transmit electronic effects between paramagnetic centres separated from each other by more than 5 A.