Intrazeolitic transition metals, such as Ni2+ and Co2+, were chelated
by open or closed, tetra- or pentadentate polyamine ligands. Their coo
rdination and redox chemistry was studied by IR-Raman, EPR, diffuse re
flectance. and magnetic techniques. For pseudo-octahedral complexes wi
th tetradentate ligands, the presence of the zeolite favors cis coordi
nation over the trans form. This is explained by the very low tendency
of the zeolite surface to bind as a monodentate ligand to a planar me
tal complex. However, if trans complexes are formed (as with Ni2+), th
e axial positions on the complex are available for ligand exchange. Su
ch intracrystalline complex syntheses result in the formation of new r
edox solids. For example, [Co-II(cyclam)](2+)-NaY (cyclam = 1,4,8,11-t
etraazacyclotetradecane) is a reversible, high-affinity (p(1/2) <1 mba
r) and high-capacity (> 90 mu mol g(-1)) dioxygen-sorbing material.