Synthesis,Crystal Structure And Luminescent Properties Of Co(?),Ni(?) And Zn(?) Salamo-Type Complexes

Due to the diversity of Salen-like compounds in structure and properties,the study of Salen-like compounds has been attatached importance to many coordination chemistry researchers.However,for the sake of further enrichment Salen-like ligands and their derivatives(–CH=N–(CH)_n–N=CH–),Salamo-like ligands containing bisoxime groups(–CH=N–O–(CH)_n–O–N=CH–)were explored by modifying the basic framework of salen-type ligands.The large electronegativity of oxygen atoms will affect the electronic properties of N₂O₂ coordination cavity,which is of great significance for obtaining novel complexes with new properties.Owing to the advantages of good stability and strong coordination ability of Salamo-like ligands,the research of Salamo-like ligands and their complexes are gradually rising,and their applications in molecular probes,catalysis,magnetism and bacteriostasis emerge one after another.The diversity of Salamo-like ligands and their complexes can be enriched by introducing aldehydes containing functional groups and extending the dioxime oxygen bridge in diamine.At the same time,in the development of Salamo-like compounds,we also pay attention to the use of various auxiliary ligands,which will be expected to obtain more novel complexes.All of these will help to expand the scope of Salamo-like ligands compounds and provide a premise for exploring new potential applications.Firstly,1,2-bis(aminoxy)ethane was reacted with 2-hydroxy-5-nitrobenzaldehyde in a ratio of 1:2,The half-Salamo-like ligand HL¹ was obtained by column chromatography.The ligand was reacted with Ni(OAC)₂·4H₂O to cultivate single crystals,and the crystallographic date showed that it is a mononuclear complex[Ni(L¹)₂](1).The physicochemical characterization,theoretical calculation and fluorescence properties of the ligands HL¹ and complex 1 were studied in detail.Secondly,1,3-dia(minoxy)propane reacted with 8-formyl-4-methylumbelliferone in a ratio of 1:2 to synthesize a symmetric single-Salamo-type ligand H2L² with good flexibility was synthesized and obtained single crystals of the ligand H2L².The ligand interacted with different metal ions in d-region,and the single crystals of complex 2-8 has been successfully grown.whichare[{Co(L²)(MeOH)(?-OAc)}₂Co]·6MeOH(2),[{Co(L²)(Et OH)(?-OAc)}₂Co]·2Et OH·2CH₂Cl₂(3),[{Ni(L²)(H₂O)(?-OAc)}₂Ni]·6Me OH·0.442H₂O(4),[{Ni(L²)(EtOH)(?-OAc)}₂Ni]·4EtOH(5),[{Ni(L²)(MeOH)(?-PhCOO)}₂Ni]·2MeOH·4H₂O(6),[Ni₄(L²)₂(?₃-OMe)₄(MeOH)₄](7),[Zn₂(L²)₂(?-OH)]·NH(CH₂CH₃)₃·2MeOH·0.5H₂O(8).The structure and properties of the above single crystals were characterized by conventional physicochemical methods.The influences of anionic effect,solvent effect,auxiliary ligand effect and flexibility of ligand on the single crystal structure of complex 2–8 were discussed.Finally,based on the 1:1 reaction between ligand HL¹ and8-formyl-4-methylumbelliferone,the asymmetric single-Salamo-type ligand H2L³ was obtained.A trinuclear complex[{Ni(L³)(DMF)(?-OAc)}₂Ni]·2Et OH·2CH₂Cl₂(9)has been synthesized by the reaction of the ligand H₂L³ with Ni(OAC)₂·4H₂O in mixed solvents.The complex 9 was characterized by a series of conventional methods.Hirshfled surface analysis was used to explore the short-range interaction of complex 9,and the fluorescence properties and DFT calculation of complex 9 were studied.