کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1330865 978981 2010 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Alkyl group dependence on structure and magnetic properties in layered cobalt coordination polymers containing substituted glutarate ligands and 4,4′-bipyridine
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Alkyl group dependence on structure and magnetic properties in layered cobalt coordination polymers containing substituted glutarate ligands and 4,4′-bipyridine
چکیده انگلیسی

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)]n (1, mg=3-methylglutarate) forms a (4,4) rhomboid grid structure based on the connection of {Co2(CO2)2} dimeric units. Using the more sterically encumbered ligands 3,3-dimethylglutarate (dmg) and 3-ethyl, 3-methylglutarate (emg) generated {[Co(dmg)(bpy)(H2O)]·2H2O}n (2) and {[Co(emg)(bpy)(H2O)]·H2O}n (3), respectively. These complexes manifest {Co(CO2)}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)]n (4), and the unsubstituted glutarate (glu) generated [Co(glu)(bpy)]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 {Co2(CO2)2} dimers. The D parameter in this series varied between 21.8(8) and 48.0(9) cm−1. However weak antiferromagnetic coupling was observed in 1 (J=–2.43(4) cm−1) and 4 (J=−0.89(2) cm−1), while weak ferromagnetic coupling appears to be operative in both 2 (J=0.324(5) cm−1) and 3 (J=0.24(1) cm−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 {Co2(CO2)2} units, while two manifest {Co(CO2)}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).Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Solid State Chemistry - Volume 183, Issue 2, February 2010, Pages 291–303
نویسندگان
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