Syntheses,Photocatalytic Activities And Photocurrent Responses Of Coordination Complexes Based On Hybrid Phosphine Ligands

Over the years,a large number of coordination complexes formed by various phosphine ligands with metal atoms like Au(?),Ag(I),Cu(?)have gained diversiform applications in catalysis,fluorescence,electrochemistry,adsorption and degradation of water pollutants.Hybrid phosphine ligands such as P-S,P-N hybrid ligands have attracted more and more attention because of their richer coordination sites and stronger coordination abilities.However,owing to the difficulties of both the ligand syntheses and the the S atoms regulation,there are few related reports.In this thesis,we designed and synthesized a new enolizable P-S hybrid ligand N',N'-2,2-tetrakis(diphenylphosphanylmethyl)thiocarbohydrazide(tpptch).We utlized it to react with AgX(X=Br,I,CN),respectively.Four complexes(1-4),whose S atoms with different coordination modes were prepared.The effects of the coordination modes of S atoms with Ag(?)atoms on the photodegradation of organic dyes in water and their photocurrent responses were investigated.In addition,we introduced the nitrile group(-C?N)into phosphine ligand and obtained two new P-CN hybrid ligands 3-bis(diphenylphosphanylmethyl)aminobenzonitrile(3-bdppmab)and 4-bis(diphenylphosphanylmethyl)aminobenzonitrile(4-bdppmab).A total of five complexes(5-9)of Ag(?)or Cu(?)of these two ligands were synthesized,and their fluorescence,cyclic voltammetry and photocurrent response properties were also investigated.The main contents of this paper are described as follows:1)A brief review has been made on the syntheses and properties of P-S,P-N hybrid ligands and their coordination complexes.2)A new P-S hybrid ligand tpptch has been designed and synthesized.Reactions of AgX with tpptch gave rise to three tetranuclear Ag(I)complexes[Ag4Br2(tpptch)2]Br2(1),[Ag4I2(tpptch)2]I2(2),[Ag4(dptpptch)2(CN)2](4,dptpptch is the anion of deprotonated tpptch)and a ID coordination polymer[Ag2I2(tpptch)]n(3).Their structures were characterized by IR,organic elemental analysis,MS,NMR,X-ray single crystal diffraction and PXRD.The coordination modes of S atoms with Ag(I)atoms of these complexes are different.They were used as photocatalysts for the photodegradation of organic dyes(eriochrome black T(EBT),malachite green(MG),sunset yellow(SY),golden orange ?(OI),golden orange ?(OII),amido black(AB),amaranth red(AR),methyl blue(MB)and methyl orange(MO))under UV light in water.The order of photodegradation was consistent with the order of the corresponding photocurrents.The effects of the coordination modes of S atoms on the photocatalytic performance and the photocurrent responses of these complexes were studied by density functional theory(DFT)calculation.3)Two new P-CN hybrid ligands 3-bdppmab and 4-bdppmab were designed and synthesized successfully.Five new complexes[Cu(3-bdppmab)I]2(5),[Cu(3-bdppmab)2BF4](6),[Ag(4-bdppmab)I]2(7),[Ag(4-bdppmab)2BF4](8),[Cu(4-bdppmab)I]2(9)were prepared by reacting these two ligands with AgI,AgBF4 and CuI,respectively.Their structures were also characterized in detail by the above methods.The fluorescence properties of the two ligands and the cyclic voltammetry and photocurrent responses of complexes 5,7 and 9 were performed.