Synthesis, Characterization And Properties Of The Keggin Type Organophosphines Acid-heteropoly Acid

Major:Applied ChemistrySpeciality:Fine Organic Synthesis and Organic Cataly~sSupervisor:Professor Fu XiangkaiAuthor:Chen JingrongHeteropoly acid (HPA) chemistry has a long history of more than one century, and it has developed rapidly since 1980s. The developing features of the modern HPA chemistry are as follows: (I) The synthesis of new type of HPA compounds still serves as impetus for its development; ? The synthesis of functional HPA compounds and its exploring become a new impetus during this decade; particularly, the rapid development of supermolecule compounds is noted in the fields such as material science and medical chemistry; @) The intersection and permeation among subjects provide space for the development of HPA chemistry; (4) In the research field of HPA chemistry, the adopting of spectroscopic methods such as NMR, ESR; experiment methods such as fine electrochemistry, tetracyclic diffraction, XAFS and the quantum chemistry calculation promotes further understanding of the structure and function of HIPA.The I-IPA with organophosphnic acids as the coordinate center have been confirmed during 1980s, in which the molar ratio P: W are 4:4, 2:6, 8:12, 2:11, 1:6, 1:7. No LIPA with organophosphonic acids as the coordinate center possessing the P: W molar ratio larger than 1:8 was reported. The coordinate center of the tungstophosphoric acid of the Keggin type structure is still inorganic phosphoric acid yet.In this paper, by reaction of fourteen organophosphonic acids (2a-2n) with Na2WO4 . 2H20, acidification with HC1 and extraction with ether,, fourteen corresponding heteropolytungsto-organophosphonic acid (3a-3n) have been prepared for the first time. They are: AEPA-HPW, DMAEPA-HPW, TMAEPA-IHIPW, n-B AEPA-L=LPW, i-PAEPA-HPW, ThAEPA-HPW, EAAEPA-HPW, ESAEPA-HPW, EDAEPA-LIPW, EOAEPA-HPW, PAEPA-HPW, MLAEPA-HPW, MZAEPA-HPW and SEPA-HPW. The fourteen new FLPA were characterized by means of CLIN elementary analysis, P W weight analysis, scanning electron microscope and energy-dispersive X-ray analysis, IR, UV, 2W, XPS, TG and DSC thermal analysis and so on. The results indicate thattheir primny StrUCtUre of the fourteen new arA is Keggin boe, and the ratio ofP:W is 1: 12. In which, the organic side chain and the PhosPhonate grouP PO3H2as the coordinate cellter paticipate aItOgether in the formation of the primarystructUre of the heteropoly anion. In other words, the entirety of the eachorganOPhosPhonic acid are as the core or coordinate cente of the HPA. Theorganic side chain of the organOPhosPhonic acid is sitUated in the SPace ofskeIeton ofheterooly anions.The most remarkale chemical ProPerty of HPA is having both acidity andoxidiZability. The acid number in ethanol of tUngstoPhosPhoric acid (PWl2) andnew HPA (3a3n) was measured by the poteniometric titration methOd. Theresults indcate that all the acid nUIner of them in ethanol is about 3. Theacidfy boction fu of fOUrteen new HPA (3a3n) was measured by means ofUV spectra and HaInmett indicato method in acedtrile. Their oxidhablitywas stUdied by the linear scanning polarograPic method. According to theresults, acidity and oxidizability of fOurteen new HPA (3a3n) are aPPrsimateto the inorgedc PWl2. The effects of the substituted grouP and the ortwc sidechain on the acid nUmer acid Shagth and okidisability of the fotheen newW (3a-3n) are also discussed.The synthesis of the first time of the Keggin tyPe heteroPolytUngsto~organo-phosPhonic acid marks tha the research field of the Keggin' tyPe HPA iseXtended frOm inoguic PhosPhoric acids to organoPhosPhonic acids, thus itwidens the SPace of theoreticaI research as weIl as aPPlicaton fOr HPAchemistry. The theoretical significans and academic values are quite aPParen.