EFFECT OF COORDINATED ANION IN CONFIGURATIONAL CONVERSION OF A TETRAAMINE MACROCYCLIC LIGAND COMPLEX OF COPPER(II)

[[abstract]]For an investigation of the effect of a coordinated anionic ligand in the configurational conversion of a tetraamine macrocyclic ligand complex of copper( II), the kinetics of the blue-to-red interconversion of the copper(I1) complex of meso- 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane in the presence and absence of anionic ligands has been examined at 25 OC by using spectrophotometric techniques. This reaction is catalyzed by base, and the coordinated base which contains another lone pair in the vicinity of the amine hydrogen is much more reactive than free base. A concerted mechanism is proposed. The reactivity order for the blue-to-red interconversion of [Cu(tet a)L(blue)]+ is [Cu(tet a)(OH)(blue)]+ > [Cu(teta)(SH)(blue)]+ > [Cu(teta)(OAc)(blue)]+ > [Cu(teta)(N02)(blue)]' >> [Cu(teta)Cl(blue)]+, [Cu(teta)Br(blue)]+, [Cu(tet a)I(blue)]+, [Cu(tet a)(SCN)(blue)]+, and [Cu(tet a)N3(blue)lf. The important factors determining the reactivity of these complexes are considered.[[fileno]]2010337010013[[department]]化學