TY - JOUR
T1 - Network dimensionality and ligand flexibility in lanthanide terephthalate hydrates
AU - Zehnder, Ralph A.
AU - Renn, Robert A.
AU - Pippin, Ethan
AU - Zeller, Matthias
AU - Wheeler, Kraig A.
AU - Carr, Jason A.
AU - Fontaine, Nick
AU - McMullen, Nathan C.
N1 - Funding Information:
This work was supported at the University of Louisiana at Monroe by the Department of Chemistry. We would like to thank the Louisiana Board of Regents for the sponsorship of this research under contract#: LEQSF(2007-10)-RD-A-40. Funding for the X-ray diffractometer at Youngstown State University was provided by NSF Grant 0087210, Ohio Board of Regents Grant CAP-491, and by Youngstown State University. Funding for the X-ray diffractometer at Eastern Illinois University was provided by the National Science Foundation (CHE-0722547). We also thank Dr. Laura Beal (Department of Chemistry, University of Louisiana) for helpful comments and discussions.
PY - 2011/1/15
Y1 - 2011/1/15
N2 - Various lanthanide open framework materials incorporating the terephthalate (TP) entity were prepared using hydrothermal synthesis methods at a moderate temperature of 170 °C. The compounds Nd2(TP)3(H 2O)4(1), Er2(TP)3(H 2O)4(2), Yb2(TP)3(H 2O)2(3), Yb2(TP)3(H 2O)6(4), and Yb2(TP)3(H 2O)8·2H2O (5), were characterized by single crystal structural analysis and FT-IR spectroscopy. While compounds 1 and 2 have been reported before on the basis of powder X-ray diffraction, the structural characterization of any ytterbium terephthalate species is unprecedented. Compounds 1-5 crystallize in triclinic settings with space group P-1. The compounds are compared with their previously reported Er and Tb-counterparts and the reduction of the dimensionality of the resulting networks from 3D over 2D to 1D with increasing level of hydration is discussed. Compounds 1, 2, and 3 with the lowest water content assemble in three-dimensional network lattices. Compounds 4 and 5, however, form 2D layered systems and 1D rod like chains, respectively, which are held together by hydrogen bonds originating from coordinating H2O. The crystal lattices of the 3D networks experience higher levels of tension as can be seen by increasing out-of-plane torsion with regard to the terephthalate carboxylate groups. Moreover, there seems to be a correlation between the level of strain on the aromatic ligands and the reduction of the number of carboxylate oxygen atoms that are part of the coordination polyhedra.
AB - Various lanthanide open framework materials incorporating the terephthalate (TP) entity were prepared using hydrothermal synthesis methods at a moderate temperature of 170 °C. The compounds Nd2(TP)3(H 2O)4(1), Er2(TP)3(H 2O)4(2), Yb2(TP)3(H 2O)2(3), Yb2(TP)3(H 2O)6(4), and Yb2(TP)3(H 2O)8·2H2O (5), were characterized by single crystal structural analysis and FT-IR spectroscopy. While compounds 1 and 2 have been reported before on the basis of powder X-ray diffraction, the structural characterization of any ytterbium terephthalate species is unprecedented. Compounds 1-5 crystallize in triclinic settings with space group P-1. The compounds are compared with their previously reported Er and Tb-counterparts and the reduction of the dimensionality of the resulting networks from 3D over 2D to 1D with increasing level of hydration is discussed. Compounds 1, 2, and 3 with the lowest water content assemble in three-dimensional network lattices. Compounds 4 and 5, however, form 2D layered systems and 1D rod like chains, respectively, which are held together by hydrogen bonds originating from coordinating H2O. The crystal lattices of the 3D networks experience higher levels of tension as can be seen by increasing out-of-plane torsion with regard to the terephthalate carboxylate groups. Moreover, there seems to be a correlation between the level of strain on the aromatic ligands and the reduction of the number of carboxylate oxygen atoms that are part of the coordination polyhedra.
KW - Crystal structures
KW - Ionic radius
KW - Lanthanide coordination polymers
KW - Network dimensionality
KW - Out-of-plane torsion
KW - Terephthalic acid
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U2 - 10.1016/j.molstruc.2010.10.030
DO - 10.1016/j.molstruc.2010.10.030
M3 - Article
AN - SCOPUS:78649944909
SN - 0022-2860
VL - 985
SP - 109
EP - 119
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
IS - 1
ER -