title: Co(II) and Ni(II) complexes based on anthraquinone-1,4,5,8-tetracarboxylic acid (H4AQTC): canted antiferromagnetism and slow magnetization relaxation in {[Co2(AQTC)(H2O)6]·6H2O}.
abstract: Three coordination polymers {[Co2(AQTC)(H2O)6]·6H2O}n (1), {[M2(AQTC)(bpym)(H2O)6]·6H2O}n (M = Co(2), Ni(3)) have been synthesized and structurally characterized, where H4AQTC is anthraquinone-1,4,5,8-tetracarboxylic acid and bpym is 2,2'-bipyrimidine. Complex 1 features a 3-D structure, where layers of Co2(AQTC) are cross-linked by Co-H2O chains. Complexes 2 and 3 are isostructural and display 1-D chain structures. The chains are connected through hydrogen-bonding interactions to form 3-D supramolecular structures. Magnetic properties of these complexes are investigated. Compound 1 shows canted antiferromagnetism and slow relaxation below 4.0 K. For complexes 2 and 3, dominant antiferromagnetic interactions are observed. The luminescent properties of the three complexes are investigated as well.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Yan
authors.forename: Song-Song
authors.initials: SS
authors.lastname: Bao
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Ren
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Sheng
authors.forename: Zhong-Sheng
authors.initials: ZS
authors.lastname: Cai
authors.forename: Chang-Sheng
authors.initials: CS
authors.lastname: Lu
authors.forename: Qing-Jin
authors.initials: QJ
authors.lastname: Meng
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng