SYNTHESIS AND PHYSICO-CHEMICAL INVESTIGATIONS ON 16 AND 18 MEMBERED (N_4) MACROCYCLES MODIFIED WITH APPROPRIATE CARBONYL FUNCTIONS - A CLOSER MIMIC TO A SYNTHETIC CYCLIC TETRAPEPTIDE; ISOLATION OF STABLE ENCAPSULATED DERIVATIVES WITH Zn (II), Cd (II)

摘要

Reaction of 1,2-diamine or 1,3-diamine with succinic/ phthalic anhydride in 1:1 molar ratio at RT in dioxane results in 16-membered or 18 membered macrocycle which posseses tetraamide/ tetrapeptide functions in the molecular unit which however, exhibit ample reactivity towards metallic substrates affording stable compounds with (MLX_2) (M=Zn, Cd or Hg; X = Cl, SCN or ClO_4) stoichiometry as evidenced from the physico-chemical investigations which confirm that the macrocyclic moieties (L_1 - L_6) have the appropriate cavity sizes to encapsulate Zn(II), Cd (II) or Hg(II) ions via coordination through nitrogens of the amide/ peptide functions in tetradentate fashion and the metal ions acquire hexa coordination.