Syntheses,Crystal Structures And Properties Of Their Metal Complexes Based On Coumarin Skeleton Ligands

Coumarin heterocyclic compounds contain benzopyrone structures in their molecules.Some of them are derived from the natural world,while others come from artificial synthesis,therefore they are easy to obtain.The molar masses of these compounds are usually small,their molecular structure is special,they have relatively high fluorescence quantum efficiency and large Stokes shift,so they have very excellent chemical activity and stable optical properties.Moreover,this type of compound has a high degree of conjugation throughout the molecule and charge transfer is easy to occur.Based on these properties,various functional groups are introduced at different positions of the coumarin ring to synthesize derivatives with unique functions,which can be applied to molecules self-assembly,material engineering,and biomedical fields,respectively.This paper first introduced the recent research of the coumarin compounds.design and synthesis these three types of coumarin-like compounds by using the benzopyran-2-one,4-hydroxy-benzopyran-2-one and 4-methyl-7-hydroxybenzopyran-2-one as raw materials.Four coumarin type derivatives are synthesized by the reaction of coumarin with different aldehydes or amines.Because all these derivatives contain functional groups such as carbon-nitrogen double bonds and phenolic hydroxyl groups,they are easy to coordinate with transition metal ions and form various complexes with different molecular space configurations.Therefore,the aim of this paper is to study the designed target ligands and complexes,discuss the crystal structure and optical properties of the target product.The specific work is as follows:Firstly,The structure,properties,classification,synthesis methods and applications in various fields of coumarin derivatives are described separately.The progress in the application of these compounds used as fluorescent probes is emphatically introduced.Secondly,A series of chemical reactions were designed to synthesize 6-aminobenzopyran-2-ketone,3-amino-4-hydroxy-benzopyran-2-ketoneand4-methyl-7-hydroxy-8-aldehydebenzopyran-2-ketone three kinds coumarin intermediates by using benzo-2-ketone,4-hydroxybenzo-2-ketone and 4-methyl-7-hydroxybenzo-2-ketone,respectively.Thirdly,the above three coumarin intermediates react with the corresponding aldehydes or amines to obtain four new coumarin derivatives.The ligands are HL¹（6-[（4-diamino-2-hydroxy-benzylidene）-amino]-benzopyran-2-one）,HL²（6-[（2-hydroxy-4-methoxy-benzyl）-amino]-benzopyran-2-one）,H₂L³（4-Hydroxy-3-[（2-hydroxy-naphthalene-1-ylmethylene）-amino]-benzoPyrano-2-2-one）and H₂L⁴（7-hydroxy-8-[（2-hydroxy-phenylimino）-methyl]-4-methyl-chromen-2-one）,respectively.Fourthly,the corresponding complex solution is obtained by reaction of HL¹,HL²,H₂L³and H₂L⁴ with the transition metal acetate.The corresponding crystal is prepared by natural volatilization of solvent,and the corresponding crystal structure is obtained by using X-ray single crystal diffraction.The specific data are as follow:[Cu（L¹）₂]（1）:Molecular Formula C₄₀H₃₈CuN₄O₆,Mr=734.29 g/mol,monoclinic,P2₁/c space group,cell parameters:a=10.590（4）?,b=7.273（3）?,c=23.345（9）?,α=90°,β=102.347（7）°,γ=90°,Z=2,V=1756.5（12）?³,R₁=0.0713,w R₂=0.2797;[Zn（L²）₂]（2）:Molecular Formula C₃₄H₂₄N₂O₈Zn,Mr=653.94 g/mol,triclinic,P-1 space group,cell parameters:a=9.1202（6）?,b=12.2985（8）?,c=12.9973（9）?,α=83.799（2）°,β=76.063（2）°,γ=81.385（2）°,Z=2,V=1395.02（16）?³,R₁=0.0292,wR₂=0.0707;[Mn（L³）₂]·NH（CH₂CH₃）₃（3）:Molecular Formula C₄₆H₃₈MnN₃O₈,Mr=815.73 g/mol,triclinic,P-1 space group,cell parameters:a=8.9705（6）?,b=12.0309（8）?,c=18.4209（13）?,α=96.303（2）°,β=103.884（2）°,γ=101.636（2）°,Z=2,V=1864.0（2）?³,R₁=0.0496,wR₂=0.1274;[Zn₂（L³）₂（CH₃OH）₂]（4）:Molecular Formula C₄₂H₃₀N₂O₁₀Zn₂,Mr=853.46 g/mol,monoclinic,P2₁/c space proup,cell parameters:a=8.5451（9）?,b=11.6897（12）?,c=18.4893（19）?,α=90°,β=100.733（3）°,γ=90°,Z=2,V=1814.6（3）?³,R₁=0.0404,wR₂=0.1029;H₂L⁴:Molecular Formula C₁₇H₁₃NO₄,Mr=295.28 g/mol,monoclinic,P2₁/c space group,cell parameters:a=11.461（4）?,b=4.8366（18）?,c=23.742（10）?,α=90°,β=95.08（4）°,γ=90°,Z=4,V=1310.9（9）?³,R₁=0.0771,wR₂=0.1913.Using elemental analysis,FT-IR,UV-Vis and fluorescence spectrum,characterize and determine the ligands and corresponding complexes.The results show that the ligand reacts with transition metal ions to form corresponding complexes,Moreover,we found that the ligand H₂L⁴ has excellent response ability of UV-fluorescence dual-channel to CN^-ion.