Synthesis,Crystal Structure And Properties Of Metal Complexes Of Novel Pyrazole Ligands

We have designed and synthesized two new ligands,these two ligands are mixed with alkali metal,alkaline earth metal and transition metal to obtain thirteen complexes in this paper.X-ray diffraction,IR spectra,¹H NMR,13C NMR,UV spectra,SEM and Powder X-ray diffraction were used for property analysis and characterization.The first synthesized ligand and abbreviation in this paper are as follows:3,5-dinitro-¹H-pyrazolyl-4-carboxylic acid?H₂dnpzc?The chemical formula of the obtained complexes are as follows:Ca?dnpzc?·5H₂O?1?B a?dnpzc?·4H₂O?2?Na2?dnpzc?·4H₂O?3?K₂?dnpzc?·H₂O?4?Ag₂?dnpzc??5?Ag₂?dnpzc?·3 H₂O?6??NH4?2?dnpzc??7?The next synthesized ligand and abbreviation are as follows:Buty1 3,5-dinitro-¹H-pyrazole-4-carboxylate?BuOOCdnpzH?The compounds and abbreviations used in this paper are as follows:4,6-Dimethyl dibenzothiophene?DMDBT?Dibenzothiophene?DBT?Benzothiophene?BT?Naphthalene?C10H8?The chemical formula of the obtained complexes are as follows:Ag₃?BuOOCdnpz?3?Ag₃pz₃??8?Ag₃pz₃·?DMDB T?2?9?Ag₃pz₃·DBT?10?Ag₃pz₃·BT·1/4THF?11?Ag₃pz₃·C10H8?12?Ag₃pz₃·CH3CN?13?Characterization of the complexs formed by the ligand?H₂dnpzc?:The synthesis and crystal structures of 3,5-dinitro-¹H-pyrazolyl-4-carboxylic acid?H₂dnpzc?and its complexes with Ca2+,Ba2+,Na+,K+,Ag+and NH4+are reported in this part.Ca?dnpzc?·5H₂O exhibits a 1-D polymeric structure while Ba?dnpzc?·4H₂O possesses a 2-D structure;the structure of Na2?dnpzc?·4H₂O consists of 2-D layers of[Na?dnpzc?]-n and 1-D chain of[Na?H₂O?3]+n;K₂?dnpzc?·H₂O has a true 3-D structure;Ag+belongs to the tri-coordination for Ag₂?dnpzc?,and forms a 2-D structure through the bridged coordination mode with the carboxyl group;Ag₂?dnpzc?further reacts with water to obtain a one-dimensional Ag₂?dnpzc?·3H₂O;?NH4?2?dnpzc?exhibits a 3-D structure.It has been observed that the doubly deprotonated ligand?dnpzc2-?can act as a versatile bridge to form polymeric structures by varying combinations of its 8 potential donor atoms?two carboxy O atoms,two pyrazolyl N atoms and four nitro O atoms?.Particularly in the structure of K₂?dnpzc?·H₂O,all the 8 donor atoms of dnpzc2-take part in the coordination and as many as 10 K atoms are connected by one ligand.The research on the ligand BuOOCdnpzH mainly includes the following aspects:1.In order to increase the 7r-acidity of the metal pyrazolato complex,we designed and synthesized Butyl 3,5-dinitro-¹H-pyrazole-4-carboxylate,and the ligand was mixed with Ag?I?to generate Ag₃?BuOOCdnpz?3.By introducing a strong electron-withdrawing group?-NO2,-COOR?on the pyrazole ring,the ?-acidity of triangular was increased.2.A series of adducts of Ag₃?BuOOCdnpz?3 and basic molecules were synthesized,and their structures were characterized.These basic substances were thiophene derivatives,aromatic compounds naphthalene and guest small molecule acetonitrile.According to the shifts of NMR,IR,the ratio of M3pz3:thiophene and structure analyses,the order of combining intensity is:Ag₃pz₃·DMDBT>Ag₃pz₃·DBT>Ag₃pz₃·BT.3.Using organic microporous polymer PIM-1 as the matrix and Ag₃?BuOOCdnpz?3 as the filler,a mixed matrix membrane was prepared.The membrane can be used for the separation of propylene/propane with a separation coefficient of up to 200.Based on the results,we can draw the following conclusions:1.Nitropyrazolecarboxylic acid ligands?H₂dnpzc?can mix with Group ?/?metal and transition metal to form coordination polymers with various structures.The ligands show a various coordination pattern.2.The introduction of strong electron-withdrawing groups?such as nitro and ester groups?into the pyrazole ring can greatly increase the ?-acidity of the trinuclear silver pyrazolato complexs.The presence of ester groups with long alkyl chains?such as n-butyl ester?can effectively improve the fat solubility of silver pyrazolato complexes,which is conducive to the subsequent research of such complexes.3.Trinuclear silver pyrazolato complexs with ?-acidity and ?-basicity substances such as thiophene derivatives can form stable adducts.This study provides experimental evidence for the application of silver pyrazolato complexes in new fuel desulfurization materials.