A series of anionic host coordination polymers based on azoxybenzene carboxylate: structures, luminescence and magnetic properties. Issue 41 (9th October 2017)

• Record Type: Journal Article
• Authors: Feng, Xun; Guo, Nan; Chen, Haipeng; Wang, Helin; Yue, Lingyun; Chen, Xin; Ng, Seik Weng; Liu, Xinfang; Ma, Lufang; Wang, Liya
• Is Part Of: Dalton transactions. Volume 46:Issue 41(2017)
• Page Start: 14192
• Page End: 14200
• Publication Date: 2017-10-09
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt02974h
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Series of luminescent or magnetic coordination polymers based on azoxybenzene tetracarboxylic acid and bipyridine have been afforded, and characterized systematically. Abstract : A series of coordination polymers {[Ln(aobtc)(H2 O)4 ]·Hbipy·H2 O} n (H4 aobtc = azoxybenzene-2, 2′, 3, 3′-tetracarboxylic acid, bipy = 4, 4′-bipyridine, and Ln = Sm(1 ), Eu(2 ), Gd(3 ), Tb(4 ), Dy(5 ), Er(6 )) have been synthesized and characterized systematically. The cationic Hbipy + guest incorporated polymers are isostructural sets, featuring a one-dimensional (1D) zigzag double chain edifice composed of binuclear clusters [Ln2 (H4 aobtc)2 ], with the Hbipy + guest being located on two sides. These 1D chains are further interlinked into a 2D layer structure, and further extended into a 3D framework through hydrogen bonding interactions. The luminescence emission spectra of polymers2 and3 are based on the H4 aobtc acid ligands, while1 and4 display the characteristic f–f transitions of Ln(iii ) ions. Magnetic measurements revealed the presence of ferromagnetic behavior in polymer3 . The magnetic behaviors of4 and6 are ascribed to the depopulation of the Stark levels and/or weak antiferromagnetic interactions within MOFs at lower temperature. Slow relaxation is observed through the alternating-current susceptibility measurements for5 at lower temperature, and the coexistence of weak ferromagnetism corresponding to the spin-canting-like behavior.