Synthesis,Structures And Optical Properties Of W(Mo)/S/Cu Cluster-based Coordination Polymers Constructed By Nitrogen-containing Heterocyclic Ligands

W(Mo)/S/Cu cluster coordination polymers have rich and varied structures,and have potential applications in third-order nonlinear optics,solvent chromic,adsorption and sensing,etc.In this paper,10 new W(Mo)/S/Cu coordination polymers were synthesized by using different functional nitrogen-contain heterocyclic organic ligands and W(Mo)/S/Cu clusters.The structures of these cluster-based coordination polymers were determined by single crystal diffraction.The third-order nonlinear optical properties of cluster based coordination polymers and their luminescence sensing properties for nitroaromatic ring explosives and metal cations are studied.Among the 10 newly cluster-based coordination polymers,there are2 supramolecular structures,2 two-dimensional structures and 6 three-dimensional structures.The molecular formula is as follows:(1){[NH₄][WS₄Cu₄(dpypy)Cu(CN)₄]·DMF}_n;(2)[WS₄Cu₃Br(tpb)·DMF]_n;(3)[(WS₄Cu₄)_1/2(dpn)(CN)]_n;(4)[(WS₄Cu₄)_1/2(dpa)_3/2I·DMF]_n;(5)[WS₄Cu₃(dpva)_3/2(SCN)]_n;(6){[WS₄Cu₄I₄[Ni(pbpp)₂]]₂·DMF}_n;(7){WOS₃Cu₃Cl₃[Ni(pbpp)₂]}_n;(8){WOS₃Cu₃Br₃[Ni(pbpp)₂]}_n;(9)[WS₄Cu₄(4,4-bpy)_5/2(SCN)₂]_n;(10)[(NH₄)₃WS₄Cu₄(pdca)(CN)₃]_n?Where,dpypy=3,5-bis(4-pyridine)pyridine,tpb=1,2,4,5-tetra-pyridine(4-pyridine)benzene,dpn=1,4-bis(4-pyridine)naphthalene,dpa=9,10-bis(4-pyridine)anthracene,dpva=9,10-bis(2-pyridine)4-yl)-vinyl)anthracene,pbpp=4-phenyl-2,6-bis(2'-pyrazinyl)pyridine,4,4-bpy=4,4-bipyridine,pdca=pyridine 3,5-dicarboxylic acid.Two novel W/S/Cu cluster coordination polymers 1 and 2 were constructed based on multi-dentate bridged functional ligands dpypy and tpb.Structurally,1 possesses an unprecedented(3,3,7)-connected 3D framework,constructed from the first 7-connected W(Mo)/S/Cu building clusters,3-connected Cu⁺and dpypy building units,and single/double CN^-bridges.2 is fabricated by the 3-connected T-shaped[WS₄Cu₃]⁺building clusters,4-connected tpb building units and capped Br^-to form binodal two-dimensional network architecture.In addition,Z-scan tests show that 1 has excellent third-order nonlinear optical absorption and refraction properties.Naphthalene/anthracene chromogroup functional ligands dpn,dpa and dpva were deliberately selected to construct three W/S/Cu clusters with tunable Fe³⁺sensing properties3?5.Structurally,3 possesses a 2-fold interpenetrated 3D diamondoid(dia)framework structure,which is constructed by pentanuclear clusters[WS₄Cu₄]²⁺,double CN^-and naphthalene-containing dpn bridges;4 is fabricated by pentanuclear clusters[WS₄Cu₄]²⁺and single/double anthracene-containing dpa bridges to form a 5-fold interpenetrated 3D dia framework;5 contains T-shaped clusters[WS₄Cu₃]⁺,single SCN^-and single/double anthracene-containing dpva bridges,which results in a 2D[4,4]network.The luminescence sensing test shows that 3 and 4 show high efficiency in Fe³⁺detection,especially,3 than 4shows higher Fe³⁺detection ability,and their sensing mechanism is studied.Three W/S/Cu cluster coordination polymers 6?8 with novel structures were synthesized by introducing Ni²⁺metal construction units based on the chelating bridged functional multi-dentate ligand pdpp.Structurally,6 exhibits a 2D(6,3)graphene-like network,fabricated by rare pentanuclear[WS₄Cu₄]²⁺building clusters,Ni²⁺building metals,bridged and chelated pbpp and terminal I^-.7 exhibits a two-dimensional supramolecular structure,which is constructed by nest-shaped[WOS₃Cu₃]⁺clusters,Ni²⁺metal building units and pdpp ligands,where one Cu in[WOS₃Cu₃]⁺forms a coordination bond with N atom,and the capped Cl^-form a hydrogen bond with the hydrogen on the pyrazine ring;8 shows a one-dimensional supramolecular structure,which is also constructed by nest-shaped[WOS₃Cu₃]⁺as the cluster core,nickel metal building units and ligands,among which one Cu in[WOS₃Cu₃]⁺is coordinated with the N atom on the ligand,the capped Br^-is connected with the hydrogen on the pyrazine ring to form a hydrogen bond.Luminescence sensing performance studies show that 6 and 7 can be used to detect nitroaromatic explosives,and have high sensitivity and good selectivity to TNP.