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Polyoxopalladates Encapsulating Yttrium and Lanthanide Ions, [X III Pd II 12 (AsPh) 8 O 32 ] 5− (X=Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu)
Author(s) -
Barsukova Maria,
Izarova Natalya V.,
Biboum Rosa Ngo,
Keita Bineta,
Nadjo Louis,
Ramachandran Vasanth,
Dalal Naresh S.,
Antonova Nadya S.,
Carbó Jorge J.,
Poblet Josep M.,
Kortz Ulrich
Publication year - 2010
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.201000631
Subject(s) - lanthanide , yttrium , chemistry , crystallography , inorganic chemistry , crystal structure , nuclear chemistry , ion , organic chemistry , oxide
A series of novel yttrium‐ and lanthanide‐containing heteropolyoxopalladates have been prepared and isolated as hydrated sodium salts, Na 5 [X III Pd II 12 (AsPh) 8 O 32 ]⋅ y H 2 O (X=Y ( 1 ), Pr ( 2 ), Nd ( 3 ), Sm ( 4 ), Eu ( 5 ), Gd ( 6 ), Tb ( 7 ), Dy ( 8 ), Ho ( 9 ), Er ( 10 ), Tm ( 11 ), Yb ( 12 ), Lu ( 13 ); y =15–27). The polyanions [X III Pd II 12 (AsPh) 8 O 32 ] 5− consist of a cuboid framework of twelve Pd II ions with eight phenylarsonate heterogroups located at the vertices and a central guest ion X. The compounds 1 – 13 have been prepared in a simple one‐pot self‐assembly reaction of Pd(CH 3 COO) 2 , phenylarsonic acid and the respective salt of the element X in 0.5 M aqueous sodium acetate solution (pH 6.9), and characterized in the solid state by single‐crystal X‐ray diffraction, elemental and thermogravimetric (TGA) analyses, and IR spectroscopy. It was demonstrated that small, medium, and also large lanthanide ions can be incorporated in the center of the novel heteropolypalladate [X III Pd II 12 (AsPh) 8 O 32 ] 5− . The LnO bond lengths follow the expected trend decreasing from left to right in the lanthanide series. This indicates that the {Pd II 12 O 32 } shell can adjust to the coordination requirements of the encapsulated guest cation. Compounds 3 and 5 were selected for electrochemical studies. Their cyclic voltammetry in a lithium acetate buffer at pH 5.9 showed a Pd 0 deposition process on the glassy carbon electrode surface. Coulometry indicated that all Pd II centers were reduced to Pd 0 . The film was stable and could be taken out of the deposition medium and characterized in pure pH 5.9 buffer. Magnetic susceptibility and EPR measurements were carried out on 5 and 6 . The former was confirmed to be diamagnetic and the latter strongly paramagnetic with a S =7/2 ground state. DFT calculations for some of the polyoxometalates have been also performed.