Six Flexible and Rigid Co(II) Coordination Networks with Dicarboxylate and Nicotinamide-Like Ligands: Impact of Noncovalent Interactions in Retention of Dimethylformamide Solvent
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- 作者：Diana Chisca ; Lilia Croitor ; Eduard B. Coropceanu ; Oleg Petuhov ; Galina F. Volodina ; Svetlana G. Baca ; Karl Krämer ; Jürg Hauser ; Silvio Decurtins ; Shi-Xia Liu ; Marina S. Fonari
- 刊名：Crystal Growth & Design
- 出版年：2016
- 出版时间：December 7, 2016
- 年：2016
- 卷：16
- 期：12
- 页码：7011-7024
- 全文大小：997K
- ISSN：1528-7505
文摘
Six mixed-ligand Co(II) coordination polymers, {[Co(adi)(iso-nia)2]·dmf}n (1), [Co(adi)(iso-nia)2]n (2), {[Co2(suc)(ac)2(iso-nia)4][Co2(suc)(sucH)2(iso-nia)4]·2dmf}n (3), [Co(adi)(nia)2]n (4), {[Co(bdc)(nia)2]·dmf}n (5), and {[Co(mal)(S-nia)(H2O)]·dmf}n (6), were synthesized and characterized by single crystal X-ray analysis. They are based on four dicarboxylic acids, namely, malonic (H2mal), succinic (H2suc), adipic (H2adi), and 1,4-benzenedicarboxylic (H2bdc) acids, as well as three nicotinamide-like ligands, isonicotinamide (iso-nia), nicotinamide (nia) and thionicotinamide (S-nia). Compounds 1, 2, and 3 represent one-dimensional coordination polymers, whereas 4, 5, and 6 exhibit two-dimensional structures. The coordination arrays in 1–5 are built from the similar [Co2(COO)2] binuclear clusters, while framework 6 is based on mononuclear metal nodes. All crystal lattices are supported by hydrogen bonding with nicotinamide-like ligands acting as pillars or dangling terminal ligands. Four crystal lattices 1, 3, 5, and 6 host dmf solvent via NH···O hydrogen bonding and π–π stacking interactions with the coordination networks. Details of the reversible dmf release–uptake by 1 and 2, and contribution of hydrogen bonding in stabilization of the solvent-free structures 2 and 4 are discussed. All new solids were characterized by IR spectroscopy and thermogravimetric analysis, while magnetic measurements are reported for compounds 1, 5, and 6. The magnetic data show the typical behavior of Co(II) ions originating from pronounced zero-field splitting within the ground state with contributing effects from weak antiferromagnetic exchange interactions.