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Metal‐organic frameworks based on uranyl and phosphonate ligands
Author(s) -
Monteiro Bernardo,
Fernandes José A.,
Pereira Cláudia C. L.,
Vilela Sérgio M. F.,
Tomé João P. C.,
Marçalo Joaquim,
Almeida Paz Filipe A.
Publication year - 2014
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520613034781
Subject(s) - pentagonal bipyramidal molecular geometry , uranyl , crystallography , chemistry , octahedron , bipyramid , dimer , methylene , molecule , phosphonate , uranyl nitrate , stereochemistry , denticity , metal , trigonal bipyramidal molecular geometry , crystal structure , uranium , medicinal chemistry , materials science , organic chemistry , ion , metallurgy
Three new crystalline metal‐organic frameworks have been prepared from the reaction of uranyl nitrate with nitrilotris(methylphosphonic acid) [H 6 nmp, N(CH 2 PO 3 H 2 ) 3 ], 1,4‐phenylenebis(methylene)diphosphonic acid [H 4 pmd, C 6 H 4 (PO 3 H 2 ) 2 ], and (benzene‐1,3,5‐triyltris(methylene))triphosphonic acid [H 6 bmt, C 6 H 3 (PO 3 H 2 ) 3 ]. Compound [(UO 2 ) 2 F(H 3 nmp)(H 2 O)]·4H 2 O (I) crystallizes in space group C 2/ c , showing two crystallographically independent uranyl centres with pentagonal bipyramidal coordination geometries. While one metal centre is composed of a {(UO 2 )O 3 (μ‐F)} 2 dimer, the other comprises an isolated {(UO 2 )O 5 } polyhedron. Compound [(UO 2 )(H 2 pmd)] (II) crystallizes in space group P 2 1 / c , showing a centrosymmetric uranyl centre with an octahedral {(UO 2 )O 4 } coordination geometry. Compound [(UO 2 ) 3 (H 3 bmt) 2 (H 2 O) 2 ]·14H 2 O (III) crystallizes in space group , showing two crystallographically independent uranyl centres. One uranyl centre is a {(UO 2 )O 5 } pentagonal bipyramid similar to that in (I), while the other is a {(UO 2 )O 4 } centrosymmetric octahedron similar to that in (II). Compounds (I) and (III) contain solvent‐accessible volumes accounting for ca 23.6 and 26.9% of their unit‐cell volume, respectively. In (I) the cavity has a columnar shape and is occupied by disordered water molecules, while in (III) the cavity is a two‐dimensional layer with more ordered water molecules. All compounds have been studied in the solid state using FT‐IR spectroscopy. Topological studies show that compounds (I) and (III) are trinodal, with 3,6,6‐ and 4,4,6‐connected networks, respectively. Compound (II) is instead a 4‐connected uninodal network of the type cds .