In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 57, No. 6 ( 2002-6-1), p. 625-630
Abstract:
Two isostructural hydroxo bridged dinuclear lanthanide phen complexes of general composition [Ln 2 (phen) 4 (H 2 O) 4 (OH) 2 ](phen) 2 (NO 3 ) 4 with Ln = Tm (1), Yb (2) were prepared by reactions of the corresponding lanthanide nitrate and phenanthroline monohydrate in CH 3 OH/H 2 O at pH = 5.5. They crystallize in the triclinic space group P1̄ (no. 2) with the cell dimensions: a = 11.233(1), b = 11.456(1), c = 14.011(2) Å , α = 93.91(1)°, β = 98.20(1)°, γ = 108.21(1)°, V = 1683.0(3)Å 3 , Z = 1 for 1 and a = 11.236(1), b = 11.480(2), c = 13.986(2)Å , α = 93.91(1)°, β = 98.17(1)°, γ = 108.33(1)°, V = 1682.9(3) Å 3 , Z = 1 for 2. The crystal structures are composed of the hydroxo bridged dinuclear [Ln 2 (phen) 4 (H 2 O) 4 (OH) 4 ] 4+ complex cations, hydrogen bonded NO 3 - anions and π-π stacking (phen) 2 dimers. The lanthanide atoms are each surrounded by two phen ligands, two H 2 O molecules and two μ-OH groups to complete a tetragonal antiprismatic LnN 4 O 4 coordination. Via two common μ-OH groups, two neighboring tetragonal antiprisms are condensed to form a centrosymmetric dinuclear [Ln 2 (phen) 4 (H 2 O) 4 (OH) 4 ] 4+ complex cation. The complex cations and (phen) 2 dimers are assembled via π-π stacking interactions and hydrogen bondings into 2D layers parallel to (101̄), between which the hydrogen bonded NO 3 - anions are sandwiched. The Tm compound shows paramagnetic behavior with an experimental magnetic moment of 7.51 μ B at room temperature. No magnetic ordering is evident down to 5 K. Over the temperature range 70 - 300 K, the Yb compound obeys the Curie-Weiss law with an experimental magnetic moment of 4.32 μ B at room temperature and shows weak ferrimagnetic behavior at low temperature.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-2002-0606
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2002
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
