Syntheses, Structures And Properties Of Mixed-Ligand Complexes Based On Aromatic Carboxylic Acid With Bis(imidazole) Pyridazine And Complexes Of Monosubstituted Pyridazine

Metal organic complexes have attracted much attention due to their interesting aesthetic structure and potential application in nanoscale magnetism,heterogeneous catalysis,gas storage and capture,photoluminescence,drug delivery,nanomaterials and so on.From a synthetic point of view,the structure of the metal organic complexes can be controlled by selecting the appropriate organic ligand and metal center as well as many reaction conditions such as solvent system,pH,reaction temperature and so on.In this paper,fifteen new complexes have been synthesized based on 3,6-bis?imidazol-1-yl?pyridazine?L¹?together with seven aromatic carboxylic acid /KSCN auxiliary ligands,3-chloro-6-?triazol/benzoimidazol-1-yl?pyridazine?L2/L3?with different metal salts.The crystal structures of complexes have been characterized.The topological analysis,thermal stabilities,photoluminescence properties and catalytic activities?the homocoupling reaction of aryl iodides?of some complexes have also been investigated.The main points in this paper are summarized as follows:1.Nine new mixed-ligand complexes have been synthesized based on L¹ and seven aromatic carboxylic acid auxiliary ligands [1,2-benzenedicarboxylic acid?1,2-H₂BDC?,1,3-benzenedicarboxylic acid?1,3-H₂BDC?,1,4-benzenedicarboxylic acid?1,4-H₂BDC?,1,3,5-benzenetricarboxylic acid?1,3,5-H3BTC?,2,6-pyridine dicarboxylic acid?2,6-H₂PYDC?,4,4?-oxydibenzoic acid?4,4?-H₂OBA?and 1,2,4,5-benzenetetracarboxylic?1,2,4,5-BTC?] reacted with different metal salts under the condition of hydrothermal/solvothermal,[Cu5?L¹??1,2-BDC?4??3-OH?2]n?1?,{[Cu4?L¹?2?1,3-HBDC??1,3-BDC???3-OH?4]·ClO4·2.6H₂O}n?2?,{[Ni?L¹??1,4-BDC?H₂O]·0.25H₂O}n?3?,[Co?L¹??1,3,5-H₂BTC?2H₂O]n?4?,{[Cu2?L¹??2,6-PYDC?2?H₂O?2]·4.4H₂O}n?5?,{[Co?L¹??4,4?-OBA?]·3.725H₂O}n?6?,{Co?L¹??1,2,4,5-BTC?0.5H₂O]}n?7?,{[Ni?L¹??1,2-BDC??H₂O?3]·H₂O}n?8?and {[Zn3?L¹?2?1,3,5-BTC?2?H₂O?2]·3H₂O}n?9?.Complexes structurally were characterized by IR spectra,single-crystal X-ray diffraction analysis and powder X-ray diffraction.The thermal stabilities,UV-vis absorption spectra and band gap energy of 1–9 have been investigated.Moreover,in the complexes-catalyzed homocoupling reaction of 4-substituted aryl iodides,the catalytic activity of 1–9 have also been studied and discussed.The complexes 1–8 have high catalytic activity to obtain the desired products when the reaction substrates bearing electron-donating groups such as-CH3 and-OCH3.The emission spectra of L¹ and complex 9 in the solid state at room temperature were investigated.2.Two new mixed-ligand complexes have been synthesized based on a neutral primary ligand L¹ together with KSCN as auxiliary ligands reacted with different Ni?II?and Cd?II?salts,[Ni?L¹?2?SCN?2]n?10?and [CdL¹?SCN?2]n?11?.The ligands 3-chloro-6-?triazol/benzoimidazol-1-yl?pyridazine?L2/L3?reacted with different metal salts and successfully prepared four complexes,[Cu?L2?2?NO3?2?H₂O?]?12?,[Cu?L2?2Cl2]n?13?,[Zn?L3?2?Cl?2]?14?and [Co?L3?2?Cl?2]?15?.Complexes structurally were characterized by IR spectra as well as single-crystal X-ray diffraction analysis.In the homocoupling reaction of 4-substituted aryl iodides,the catalytic activity of complex 10 has been studied and discussed.The recyclability of 10 has been tested for the homocoupling reaction of 4-methyl-iodobenzen and the yield of target product was slightly decreased after five cycles,which indicates that 10 has the excellent stability.The emission spectra of L¹,L3 and complexes 11 and 14,15 in the solid state at room temperature were investigated.