title: Surfactant-thermal syntheses, structures, and magnetic properties of Mn-Ge-sulfides/selenides.
abstract: Although either surfactants or amines have been investigated to direct the crystal growth of metal chalcogenides, the synergic effect of organic amines and surfactants to control the crystal growth has not been explored. In this report, several organic bases (hydrazine monohydrate, ethylenediamine (en), 1,2-propanediamine (1,2-dap), and 1,3-propanediamine (1,3-dap)) have been employed as structure-directing agents (SDAs) to prepare four novel chalcogenides (Mn3Ge2S7(NH3)4 (1), [Mn(en)2(H2O)][Mn(en)2MnGe3Se9] (2), (1,2-dapH)2{[Mn(1,2-dap)2]Ge2Se7} (3), and (1,3-dapH)(puH)MnGeSe4(4) (pu = propyleneurea) under surfactant media (PEG-400). These as-prepared new crystalline materials provide diverse metal coordination geometries, including MnS3N tetrahedra, MnGe2Se7 trimer, and MnGe3Se10 T2 cluster. Compounds 1-3 have been fully characterized by single-crystal X-ray diffraction (XRD), powder XRD, UV-vis spectra, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Moreover, magnetic measurements for compound 1 showed an obvious antiferromagnetic transition at ~9 K. Our research not only enriches the structural chemistry of the transitional-metal/14/16 chalcogenides but also allows us to better understand the synergic effect of organic amines and surfactants on the crystallization of metal chalcogenides.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Guodong
authors.initials: G
authors.lastname: Zhang
authors.forename: Peizhou
authors.initials: P
authors.lastname: Li
authors.forename: Junfeng
authors.initials: J
authors.lastname: Ding
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Xiong
authors.forename: Lina
authors.initials: L
authors.lastname: Nie
authors.forename: Tom
authors.initials: T
authors.lastname: Wu
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhao
authors.forename: Alfred Iing Yoong
authors.initials: AI
authors.lastname: Tok
authors.forename: Qichun
authors.initials: Q
authors.lastname: Zhang