Synthesis,Structures And Properties Of Guanidine Derivatives And Their Metal Complexes

In this thesis,we used guanidines as main research objective reactants,selecting a series of aminoguanidine,diaminoguanidine and triaminoguanidine compounds as raw starting materials,and synthesize a lot of Schiff base ligands according to react aminoguanidine with various aldehydes in the condensation reaction.Guanidine metal complexes were further synthesized and their crystal structural characzations and physicochemical properties were studied.Secondly,the metal complexes containing F^-、Cl^-、OH^-and oxygen-containing acids,PO₄^3-、SO₄^2-、CO₃^2-、NO₃^-、H₂NCH₂COO^-,and other anionic water clusters were synthesized.The supramolecular interactions of anionic water clusters and their effects on structural stability were also studied.Using monoaminoguanidine,diaminoguanidine and triaminoguanidine as raw materials,71 guanidine Schiff base ligands were synthesized by selective reaction with aliphatic,aromatic and heterocyclic aldehydes.All the guanidine Schiff base ligands were characterized by elemental analysis and infrared spectroscopy.The crystal structures of 18 guanidine Schiff base ligands were analyzed by Mercury 3.8and Olex2 softwares.The Hirshfeld surfaces and associated two-dimensional（2D）finger patterns for the intramolecular and intermolecular contacts of 18 guanidine Schiff base ligands were studied by Crystal Explorer Program.In terms of physicochemical properties,the antioxidant properties of guanidine Schiff base compounds were studied by DPPH and ABTS methods,and the effects of CCK8method on the activity of esophageal cancer cells were studied.It has been found that guanidine derivatives have good antioxidant properties,and some guanidine Schiff base compounds have very obvious value-added or inhibitory activities on esophageal cancer cells.At the same time,the solid-state fluorescence test of the synthesized aminoguanidine Schiff base compounds showed that most of the aminoguanidine Schiff base compounds had fluorescence properties,and the fluorescence intensity was relatively high,up to 1.0×10⁵a.u.,which is expected to be a potential new fluorescent material.Guanidine Schiff base derivatives with strong coordination ability were selected to react with metal compounds to obtain four new metal complexes containing guanidine groups,which have not been reported before.Their single crystal structures were obtained,and also analyzed using Mercury,Olex2 and Crystal Explorer program software.The catalytic performances for photocatalytic reduction of CO₂ and electrocatalytic hydrogen evolutions of these guanidine metal complexes were studied.It was found that the metal complexes containing guanidine groups had better photocatalytic CO₂reduction activity and electrocatalytic hydrogen evolution activity in acidic water.Among them,the Tafel slope of the metal complex[Co L₂]Cl·DMF（L=[（3,5-diiodoo-hydroxybenzaldehyde）amino]guanidine nitrate）was as low as 87.3mv/dec,and the compound had excellent electrocatalytic hydrogen evolution activity.Water is one of the most abundant and inexpensive natural solvent.In the study of water,water clusters are considered as a bridge between the gas phase and the concentrated phase.In this paper,the water cluster structures of six series of metal complexes with different anions were studied,and the structural morphology of anionic water clusters in metal complexes was analyzed.It is of great scientific significance to understand the solvent phenomenon,two kinds of electrical phenomena in the troposphere and ionosphere,and the mobility of ions in chemical and biological systems.It provides information and scientific basis for mastering the behavior of water molecules and solid particles in gaseous chemistry and space chemistry.