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Indexed by:期刊论文

Date of Publication:2013-10-01

Journal:EUROPEAN JOURNAL OF INORGANIC CHEMISTRY

Included Journals:SCIE、Scopus

Volume:2013

Issue:29

Page Number:5153-5160

ISSN No.:1434-1948

Key Words:Amino acids; Cluster compounds; Lanthanides; Chromium; Magnetic properties

Abstract:Reactions between Ln(3+) (Ln = Dy, Tb), Cr3+, and glycine (HGly) in aqueous solution led to two pentanuclear compounds, Na-3[Dy3Cr2(HGly)(6)((3)-OH)(6)(H2O)(9)](ClO4)(8)Cl(4)14H(2)O (1) and Na-3[Tb3Cr2(HGly)(6)((3)-OH)(6)(H2O)(9)](ClO4)(6)Cl(6)6H(2)O (2). Structural analyses showed that both 1 and 2 have a {Ln(3)Cr(2)} compressed trigonal-bipyramidal skeleton in which an axial Cr3+ ion lies above and below the triangular equatorial plane defined by the three Ln(3+) ions. Magnetic measurements indicated that 1 and 2 exhibit single-molecule magnetic behavior with E-a approximate to 14.1 K and (0) = 4.2x10(-8) s for 1 and E-a approximate to 13.0 K and (0) = 6.4x10(-7) s for 2. Interestingly, the clusters are soluble in aqueous solution. The two terminal water molecules of 1 can be substituted by two monocoordinated 4,4-dipyridyl N,N-dioxide (dpyo) molecules to afford [Dy3Cr2(HGly)(6)(dpyo)(2)((3)-OH)(6)(H2O)(7)](ClO4)(9)15H(2)O (3) with a three-dimensional cds network formed through - interactions. Magnetic analysis indicated that 3 also displays slow relaxation of the magnetization with E-a approximate to 13.24 K and (0) = 9.16x10(-8) s.