The nanoporous coordination polymer [Cu(pyrimidin-2-olate-N1,N3) 2]n (1c) of the sodalite zeotype sorbs a variety of metal nitrates [M(NO3)m M = Na+, K+, Rb+, Tl+, Ca2+, Sr2+, Ba2+, Pb2+, La3+, Nd3+, Gd 3+, Er3+] from H2O/MeOH solutions, with a concomitant structural change to a layered [Cu(pyrimidin-2-olate-N1,N3) 2]n·[M(NO3)m]n/2 (MNO3@1L) coordination framework. Single-crystal X-ray diffraction analyses revealed that the layers are based on Cu 4(pyrimidin-2-olate-N1,N3)4 square grids of copper(II) ions bridged by N1,N3 exobidentate ligands, displaying a structural motif of the metallacalixarene type in pinched cone conformation. The interlayer space is occupied by the guest metal nitrates, each metal being coordinated by (at least) the four oxygen atoms of a metallacalixarene. Magnetic measurements on the MNO3@1L series denoted a weak ferromagnetic ordering taking place below the Néel temperatures (typically close to 35 K), arising from spin-canting phenomena of the antiferromagnetically coupled copper centers. When M = Nd3+, Gd3+, or Er3+, additional magnetic ordering is observed at lower temperatures, which, on the basis of static and dynamic magnetic susceptibility measurements, can be attributed to copper-lanthanide interactions. © 2007 American Chemical Society.
|Titolo:||Structural and magnetic properties of layered copper(II) coordination polymers intercalating s and f metal ions|
SIRONI, ANGELO AGOSTINO DANIELE (Ultimo)
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1021/ic061384i|
|Appare nelle tipologie:||01 - Articolo su periodico|