title: Three novel Cu6S6 cluster-based coordination compounds: synthesis, framework modulation and the sensing of small molecules and Fe(3+) ions.
abstract: Three novel Cu6S6 cluster-based coordination compounds formulated as [Cu(mpymt)3]2 (1), {(CuBr4)[Cu(mpymt)6]}n (2), and {(CuI6)[Cu(mpymt)6]}n (3) (Hmpymt = 4-methylpyrimidine-2-thione), have been synthesized under solvothermal conditions and characterized by elemental analysis, infrared (IR) spectroscopy, thermal gravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Structural analysis reveals that compound 1 shows a distorted octahedral core of six copper atoms (Cu6S6) constructed from four α and two β type N[double bond, length as m-dash]C-SH parts from six mpymt(-) anions. Compound 2 displays an interesting 3D framework constructed from Cu6S6 and Cu4Br4 Cu(i) clusters simultaneously, interestingly, six mpymt(-) with α type N[double bond, length as m-dash]C-SH parts are involved in the formation of Cu6S6. Compound 3 displays an infinite 1D framework constructed from Cu6S6 and Cu6I6 Cu(i) clusters, notably, four α and two β type N[double bond, length as m-dash]C-SH parts are involved in the formation of the Cu6S6 cluster, however, only mpymt(-) ligands containing α type N[double bond, length as m-dash]C-SH parts form the bridged Cu6I6 cluster. The experimental results reveal that halogen ions finely modulate the structural features of compounds 1-3. The fluorescent properties of compounds 1-3 in the solid state and in various solvent emulsions were investigated in detail, the results of which indicate that compounds 1-3 are all highly sensitive naked eye colorimetric sensors for NB, 2-NT and Fe(3+) (NB = nitrobenzene and 2-NT = 2-nitrotoluene).
authors.affiliation: Department of Chemistry, North University of China, Taiyuan, Shanxi 030051, P. R. China. jfsong0129@nuc.edu.cn.
authors.forename: Jiang-Feng
authors.initials: JF
authors.lastname: Song
authors.forename: Si-Zhe
authors.initials: SZ
authors.lastname: Li
authors.forename: Rui-Sha
authors.initials: RS
authors.lastname: Zhou
authors.forename: Jia
authors.initials: J
authors.lastname: Shao
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Qiu
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Jia
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang