Synthesis and characterization of a new chelating polymer and its metal complexes

Abstract The monomer exo-7-isopropylidenebicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic-acidanhydride (I) [J.H. Day, Chem. Revs., 53 (1953) 167] undergoes smooth homopolymerization using the WCl 6 /(CH 3 ) 4 Sn or MoCl 5 /(CH 3 ) 4 Sn based ring opening metathesis polymerisation initiators to give a polymer (PI). Aiming to synthesize a chelating polymer, the monomer (I) was treated with the potential complexing agent S-methylhydrazinecarbodithioate to give monomer (II) which was subjected to metathesis polymerization using WCl 6 and MoCl 5 based catalysts. Unfortunately, the formation of complexes between (II) and these initiators completely inhibits ring opening polymerization. However, the synthesis of polymer containing chelating group (PII) was achieved by treating (PI) with NH 2 NHCSSCH 3 in DMF as solvent. The chelating polymer (PII) reacts with metal(II) acetates in a 2:1 repeating unit: metal molar ratio giving neutral complexes of the general formula (PIII) which are insoluble in common organic solvents. The isolated polymers and their metal complexes were characterized by elemental analysis, IR, NMR, TG and DTA measurements.