title: Homochiral nickel coordination polymers based on salen(Ni) metalloligands: synthesis, structure, and catalytic alkene epoxidation.
abstract: One-dimensional (1D) homochiral nickel coordination polymers [Ni(3)(bpdc)(RR-L)(2)·(DMF)](n) (2R, RR-L = (R,R)-(-)-1,2-cyclohexanediamino-N,N'-bis(3-tert-butyl-5-(4-pyridyl)salicylidene), bpdc = 4,4'-biphenyldicarboxylic acid) and [Ni(3)(bpdc)(SS-L)(2)·(DMF)](n) (2S, SS-L = (S,S)-(-)-1,2-cyclohexanediamino-N,N'-bis(3-tert-butyl-5-(4-pyridyl)salicylidene) based on enantiopure pyridyl-functionalized salen(Ni) metalloligand units NiL ((1,2-cyclohexanediamino-N,N'-bis(3-tert-butyl-5-(4-pyridyl)salicylidene))Ni(II)) have been synthesized and characterized by microanalysis, IR spectroscopy, solid-state UV-vis spectroscopy, thermogravimetric analysis (TGA), circular dichroism (CD) spectroscopy, cyclic voltammetric measurement, and powder and single crystal X-ray diffraction. Each NiL as unbridging pendant metalloligand uses one terminal pyridyl group to coordinate achiral unit (nickel and bpdc(2-)) building a helical chain, while the other pyridyl group remains uncoordinated. Both 2R and 2S contain left- and right-handed helical chains made of the achiral building blocks, while the NiL as remote external chiral source is perpendicular to the backbone of the helices. The nickel coordination polymers 2R and 2S containing unsaturated active nickel center in metalloligand NiL can be used as self-supported heterogeneous catalysts. They show catalytic activity comparable with their homogeneous counterpart in alkene epoxidation and exhibit great potential as recyclable catalysts.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Science, Fuzhou 350002, China.
authors.forename: Yuanbiao
authors.initials: Y
authors.lastname: Huang
authors.forename: Tianfu
authors.initials: T
authors.lastname: Liu
authors.forename: Jingxiang
authors.initials: J
authors.lastname: Lin
authors.forename: Jian
authors.initials: J
authors.lastname: Lü
authors.forename: Zujin
authors.initials: Z
authors.lastname: Lin
authors.forename: Rong
authors.initials: R
authors.lastname: Cao
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D004852:Epoxy Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D000475:Alkenes; D004852:Epoxy Compounds; D005029:Ethylenediamines; D008024:Ligands; D009942:Organometallic Compounds; D011108:Polymers; D009532:Nickel; C011452:disalicylaldehyde ethylenediamine