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Intrazeolitic Reaction between Transition Metal Ions and Open or Closed Polyamine Ligands
Author(s) -
de Vos Dirk E.,
Vanoppen Dominic L.,
Li XiaoYuan,
Libbrecht Steven,
Bruynseraede Yvan,
KnopsGerrits PeterPaul,
Jacobs Pierre A.
Publication year - 1995
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.19950010208
Subject(s) - cyclam , chemistry , ligand (biochemistry) , electron paramagnetic resonance , transition metal , redox , denticity , polyamine , metal , inorganic chemistry , chelation , crystallography , octahedron , metal ions in aqueous solution , photochemistry , catalysis , crystal structure , organic chemistry , biochemistry , physics , receptor , nuclear magnetic resonance
Intrazeolitic transition metals, such as Ni 2+ and Co 2+ , were chelated by open or closed, tetra‐ or pentadentate polyamine ligands. Their coordination and redox chemistry was studied by IR‐Raman, EPR, diffuse reflectance, and magnetic techniques. For pseudo‐octahedral complexes with tetradentate ligands, the presence of the zeolite favors cis coordination 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 metal complex. However, if trans complexes are formed (as with Ni 2+ ), the axial positions on the complex are available for ligand exchange. Such intracrystalline complex syntheses result in the formation of new redox solids. For example, [Co II ‐(cyclam)] 2+ ‐NaY (cyclam = 1,4,8,11‐tetraazacyclotetradecane) is a reversible, high‐affinity ( p 1/2 <1 mbar) and high‐capacity (>90 μmol g −1 ) dioxygen‐sorbing material.