Novel Supramolecular Assemblies of Co(III) & Cu(II) with Diethylenetriamine and Azide: Synthesis, Structure, Spectroscopic and Magnetic Studies

作者：Pandey, Priyanka; Cosquer, Goulven; Yamashita, Masahiro; Sunkari, Sailaja S.^*

来源：ChemistrySelect, 2018, 3(8): 2240-2244.

DOI：10.1002/slct.201702715

• Azide
• Cobalt (III)
• Copper(II)
• Diethylenetriamine
• Magnetic study

In exploring the role of increased ligand basicity as well as denticity on moving from ethylenediamine (en) or 1,3-diaminopropane (1,3-dap), on supramolecular solid formation, complexation involving diethylenetriamine (det) and azide with Co-II and Cu-II afforded three new complexes [Co(det)(2)](N-3)(3) (1), [Co(det)(N-3)(3)] (2) and [Cu-2(det)(2)(N-3)(5)(H2O)(2)Na] (3) under self assembling conditions and are characterized structurally and magnetically. Formation of 1 and 2 is sensitive to temperature of crystallization, while such a temperature influence could not be observed for Cu-II system due to lack of crystals at low temperatures. As expected with a tridentate ligand, strong chelation stabilizes 1 at LT and is a thermodynamically stable product, while isolation of 2 at RT conditions is under kinetic control. Decomposition of 2 at high temperatures (above 70 degrees C) as revealed through temperature dependent UV-vis spectral studies also confirms its instability. Presence of three donor sites of det, leads to interesting structural pattern in Jahn-Teller active Cu-II, resulting in cationic chains of [Cu(det)(N-3)](n)(+) bridged by -1,3 azido bridges to the neighboring [Na(H2O)(2)(N-3)(2)](-) units, thus leading to a 2-D assembly of alternating layers of cationic and anionic chains in the unit cell of 3. Magnetic studies of 3 reveals anti-ferromagnetic interaction between the copper ions (J=- 0.479cm(-1)), in conformity with the bridge angle dependent magnetic behavior in azido bridged copper complexes.

• 出版日期2018-2-28
• 单位南开大学