title: Anion-induced self-assembly of luminescent and magnetic homoleptic cyclic tetranuclear Ln4(salen)4 and Ln4(salen)2 complexes (Ln = Nd, Yb, Er, or Gd).
abstract: Unique homoleptic cyclic tetranuclear Ln(4)(Salen)(4) complexes [Ln(4)(L)(2)(HL)(2)(μ(3)-OH)(2)Cl(2)]·2Cl (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) or Ln(4)(Salen)(2) complexes [Ln(4)(L)(2)(μ(3)-OH)(2)(OAc)(6)] (Ln = Nd, 5; Ln = Yb, 6; Ln = Er, 7; Ln = Gd, 8) have been self-assembled from the reaction of the hexadentate Salen-type Schiff-base ligand H(2)L with LnCl(3)·6H(2)O or Ln(OAc)(6)·6H(2)O (Ln = Nd, Yb, Er, or Gd), respectively (H(2)L: N,N'-bis(salicylidene)cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1-2 and 5-6 with emissive lifetimes in microsecond ranges are observed, and the sensitization arises from the excited state (both (1)LC and (3)LC) of the hexadentate Salen-type Schiff-base ligand with the flexible linker. Temperature dependence (1.8-300 K) magnetic susceptibility studies of the eight complexes suggest the presence of an antiferromagnetic interaction between the Ln(3+) ions.
authors.affiliation: Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi'an 710069, Shaanxi, China.
authors.forename: Weixu
authors.initials: W
authors.lastname: Feng
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Lü
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.forename: Guoxiang
authors.initials: G
authors.lastname: Shi
authors.forename: Dan
authors.initials: D
authors.lastname: Zou
authors.forename: Jirong
authors.initials: J
authors.lastname: Song
authors.forename: Daidi
authors.initials: D
authors.lastname: Fan
authors.forename: Wai-Kwok
authors.initials: WK
authors.lastname: Wong
authors.forename: Richard A
authors.initials: RA
authors.lastname: Jones
mesh_terms: D000838:Anions / Q000138:chemical synthesis / Q000737:chemistry*; D003514:Cyclohexylamines / Q000138:chemical synthesis / Q000737:chemistry; D005029:Ethylenediamines / Q000138:chemical synthesis / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000138:chemical synthesis / Q000737:chemistry*; D008024:Ligands; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry*; D008958:Models, Molecular; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000838:Anions; D003514:Cyclohexylamines; D005029:Ethylenediamines; D028581:Lanthanoid Series Elements; D008024:Ligands; D049408:Luminescent Agents; D012545:Schiff Bases; C011452:disalicylaldehyde ethylenediamine; C030435:1,2-cyclohexanediamine