Alkyl group dependence on structure and magnetic properties in layered cobalt coordination polymers containing substituted glutarate ligands and 4,4'-bipyridine

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.11.015· OSTI ID:21372481

Nettleman, Joseph H ^[1]; Supkowski, Ronald M ^[2]

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1. Lyman Briggs College and Department of Chemistry, E-30 Holmes Hall, Michigan State University, East Lansing, MI 48825 (United States)
2. Department of Chemistry and Physics, King's College, Wilkes-Barre, PA 18711 (United States)

Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared hydrothermally and structurally characterized by single-crystal X-ray diffraction. [Co(mg)(bpy)]{sub n} (1, mg=3-methylglutarate) forms a (4,4) rhomboid grid structure based on the connection of {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} dimeric units. Using the more sterically encumbered ligands 3,3-dimethylglutarate (dmg) and 3-ethyl, 3-methylglutarate (emg) generated {l_brace}[Co(dmg)(bpy)(H{sub 2}O)].2H{sub 2}O{r_brace}{sub n} (2) and {l_brace}[Co(emg)(bpy)(H{sub 2}O)].H{sub 2}O{r_brace}{sub n} (3), respectively. These complexes manifest {l_brace}Co(CO{sub 2}){r_brace}{sub n} chains linked into 2-D by aliphatic dicarboxylate and bpy ligands. The 'tied-back' substituted glutarate ligand 1,1-cyclopentanediacetate (cda) afforded [Co(cda)(bpy)]{sub n} (4), and the unsubstituted glutarate (glu) generated [Co(glu)(bpy)]{sub n} (5), both of which exhibit a topology similar to that of 1. The magnetic properties of complexes 1-4 were analyzed successfully with a recently developed phenomenological chain model accounting for both magnetic coupling (J) and zero-field splitting effects (D), even though 1 and 4 contain isolated, discrete {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} dimers. The D parameter in this series varied between 21.8(8) and 48.0(9) cm{sup -1}. However weak antiferromagnetic coupling was observed in 1 (J=-2.43(4) cm{sup -1}) and 4 (J=-0.89(2) cm{sup -1}), while weak ferromagnetic coupling appears to be operative in both 2 (J=0.324(5) cm{sup -1}) and 3 (J=0.24(1) cm{sup -1}). - Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared and structurally characterized by single-crystal X-ray diffraction. Three contain dimeric {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} units, while two manifest {l_brace}Co(CO{sub 2}){r_brace}{sub n} chains, depending on the steric bulk of the substituent. The magnetic properties of the complexes were analyzed successfully with a recently developed phenomenological chain model accounting for both magnetic coupling (J) and zero-field splitting effects (D).

• OSTI ID: 21372481
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 2; Other Information: DOI: 10.1016/j.jssc.2009.11.015; PII: S0022-4596(09)00544-1; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANTIFERROMAGNETISM
BIPYRIDINES
COBALT COMPLEXES
CRYSTAL STRUCTURE
FERROMAGNETISM
LIGANDS
MAGNETIC PROPERTIES
MONOCRYSTALS
POLYMERS
THERMAL GRAVIMETRIC ANALYSIS
TOPOLOGY
X-RAY DIFFRACTION
AZINES
CHEMICAL ANALYSIS
COHERENT SCATTERING
COMPLEXES
CRYSTALS
DIFFRACTION
GRAVIMETRIC ANALYSIS
HETEROCYCLIC COMPOUNDS
MAGNETISM
MATHEMATICS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PYRIDINES
QUANTITATIVE CHEMICAL ANALYSIS
SCATTERING
THERMAL ANALYSIS
TRANSITION ELEMENT COMPLEXES