title: Multitopic ligand directed assembly of low-dimensional metal-chalcogenide organic frameworks.
abstract: Despite tremendous progress in metal-organic frameworks, only limited success has been achieved with metal-chalcogenide organic frameworks. Metal-chalcogenide organic frameworks are desirable because they offer a promising route towards tunable semiconducting porous frameworks. Here, four novel semiconducting chalcogenide-organic hybrid compounds have been synthesized through a solvothermal method. Multitopic organic molecules, i.e., 1,2-di-(4-pyridyl)ethylene (L1), 1,3,5-tris(4-pyridyl-trans-ethenyl)benzene (L2) and tetrakis(4-pyridyloxymethylene)methane (L3), have been used as linkers to assemble Zn(SAr)2or Zn2(SAr)4units to generate different patterns of spatial organizations. Single-crystal structural analyses indicate that compounds NTU-2, NTU-3 and NTU-4 possess two-dimensional layer structures, while compound NTU-1 adopts a one-dimensional coordination framework (NTU-n, where n is the number related to a specific structure). The diffuse-reflectance spectra demonstrate that these four compounds possess indirect bandgaps and their tunable bandgaps are correlated with their compositions and crystal structures.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore. qczhang@ntu.edu.sg and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, P.R. China.
authors.forename: Yi
authors.identifier: http://orcid.org/0000-0002-5529-8460
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore. qczhang@ntu.edu.sg and State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P.R. China.
authors.forename: Kaiqi
authors.initials: K
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P.R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore. qczhang@ntu.edu.sg and Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Qichun
authors.identifier: http://orcid.org/0000-0003-1854-8659
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, California State University, Long Beach, CA 90840, USA.
authors.forename: Xianhui
authors.identifier: http://orcid.org/0000-0002-2994-4051
authors.initials: X
authors.lastname: Bu
authors.affiliation: Department of Chemistry, University of California, Riverside, CA 92521, USA.
authors.forename: Pingyun
authors.identifier: http://orcid.org/0000-0003-3684-577X
authors.initials: P
authors.lastname: Feng