title: Syntheses, structures, and properties of high-nuclear 3d-4f clusters with amino acid as ligand: {Gd6Cu24}, {Tb6Cu26}, and {(Ln6Cu24)2Cu} (Ln = Sm, Gd).
abstract: Four novel high-nuclear 3d-4f heterometallic clusters were obtained through the self-assembly of Ln(III), Cu(II), and amino acid ligands (2-methylalanine (mAla), glycine (Gly), and L-proline (Pro), respectively). The metal skeleton of cluster 1, [Gd6Cu24(mu3-OH)30(mAla)16(ClO4)(H2O)22].(ClO4)17.(OH)2.(H2O)2(0), may be described as a huge {Gd6Cu12} octahedron connected with 12 additional Cu(II) ions. The structure of cluster 2, Na4[Tb6Cu26(mu3-OH)30(Gly)18(ClO4)(H2O)22].(ClO4)25.(H2O)42, may be described as a {Tb6Cu24} main structure connected with two [Cu(Gly)(H2O)2]+ groups. Compounds {[Ln6Cu24(mu3-OH)30(Pro)12(Ac)6(ClO4)(H2O)13]2Cu(Pro)2}.(ClO4)18.(OH)16.(H2O)55 (Ln= Sm (3), Gd (4)) are 61-nuclear clusters, which represent the largest known 3d-4f clusters so far, the structure can be described as two {Ln6Cu24} octahedral units connected by a trans-Cu(proline)2 bridge. The electrical conductivity measurements reveal that they are temperature-sensitive semiconductors. The magnetic susceptibility measurements display that compound 4 is ferromagnetic.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Sheng-Min
authors.initials: SM
authors.lastname: Hu
authors.forename: Sheng-Chang
authors.initials: SC
authors.lastname: Xiang
authors.forename: Tianlu
authors.initials: T
authors.lastname: Sheng
authors.forename: Xin-Tao
authors.initials: XT
authors.lastname: Wu
authors.forename: Ya-Min
authors.initials: YM
authors.lastname: Li
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004553:Electric Conductivity; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D012666:Semiconductors; D013696:Temperature
chemical_list: D000596:Amino Acids; D028581:Lanthanoid Series Elements; D008024:Ligands; D009942:Organometallic Compounds; D003300:Copper