Synthesis, Structure And Catalytic Properties Of Polyoxometalate-nitrogenous Organic Ligands Charge-transfer Complexes

Ten ne w charge-tr a ns fer c o mplexes cr ystals have bee n s y nthesiz ed byhydr other mal and e vapor ation method. Six of t h e m have b een resolv ed, andf o u r a r e s t i l l i n. Their struct ures were determined by si ngle-crystal X-raydi ffracti o n and c h aracterize d by I R, TG-DTA, etc. Si x kinds of knownstructure comple xe s ha ve be en used for catal yt ic eli mination of methanolresearch.This di ss ertation consist s of four parts. Fir stly, one Keggin-t ypephos phomolybdate-benzi mi da zole c har ge-trans fe r comple x was s y nthsise dby hydr other mal methods at mo dera te t e mperature. Secondly, t wocharge-tr a ns fer c o mpl exes were for me d by phos photungstic ac id and2-a minopyridine,3-picoline. Thir dly, combined wit h hydrother mal methodand solut ion e vaporation met hod, t wo c h a rg e-t r a n s fer c o mpl e x e s a b o u tsiliconmo lybdat e-di met hyla mine a nd phosphot ungstic-di methyla mine weresynthsise d. La stly, c o mbi n ed wit h hydr other mal method and solutio nevaporati on met hod, a cha rge-trans fer comple x with nove l struct ur e bas edon As2Mo6was synt hsised.1. Ph osphomolybdate-benzimidazole charge-transfer comp lexThe charge-transfer comple xe wa s synthesis ed with Keggin-t ypephos phomolybdate anion and nitrogenous organic ligands benzi mi d azole:（C₅H₇N₂）₃·（C₅H₆N₂）(PMo₁₂O₄₀)·2H₂O（1）. Comple x1cr ysta llizes in triclinic,space group P-1, with the cel l paramet ers of a=9.8980（4）, b=11.2893（4）,c=25.8933（9）, α=93.307（2）°, β=90.630（2）°, γ=108.330（2）°, V=2740.683.Z=2, R₁（F）=0.0740, ωR2（F2）=0.1511, Goof（S）=1.037. Complex1for medtwo-di me nsional fr a me work via lots of hydrogen-bonds and thr ough π-πstacking interactions forme d thre e-di me nsiona l supra molecular array. Inaddition, without any activation treat m e n t, t h e c o m p l e x1s h o w e d g o o dcatalytic activity on methanol.2. Phosphotungstic acid-pyri dines char ge-trans fe r compl exesTwo charge-trans fe r complexes consist s of phos phot ungst ic acid a nd2-a minopyridine,3-picoli ne, res pecti vely. The re molec ular for mulas are（C₅H₇N₂）₃（C₅H₆N₂）₃（P W12O40）·2H₂O （C₅H₆N₂=2-a mi nopyr idine）（c omplex2）,（C₆H₈N）₃（C₆H₇N）（P W12O40）·9H₂O （C₆H₇N=3-pic oli ne）（compl ex3）.Complex2crystallizes in t r i c l i n i c, s p a c e g r o u p P2（1）/n, with t he cell para meter s of a=13.3371（7）, b=22.5278（12）, c=21.8442（11）, α=90°,β=115.880（3）°, γ=90°, V=5905.0（5）3, Z=4. R₁（F）=0.0648,ωR₂（F²）=0.1682. Goof（S）=1.053. Complex3cr ystallizes in triclinic, spaceg r o u p P2₁/c, wit h t he cell pa ra met ers of a=12.0380（9）, b=20.1622（15）,c=26.2208（18）, α=90°, β=110.421（3）°, γ=90°, V=5964.2（8）3, Z=4.R₁（F）=0.0706, ωR₂（F²）=0.1481. Goof（S）=1.080. The π-π stackinginteractions a nd profuse hydroge n bonds endow the s triking fe ature ofc o mpl e x e s2a n d3wi t h a n interesting three-dimensional net structure. Bothof the m have good catalytic eli mination ca pacity on metha nol.3. Pol yaci d-di methyla mi ne c h arge-trans fer compl exesTwo charge-transfer complexes ba s ed on DM F decompos ition pr oductdi methyla mine and siliconmo lybdat e, p hosphot ungstic, re spectivel y. Theremol ecular for mulas are （C₂H₈N）₄SiMo₁₂O₄₀（4）,（C₂H₈N）₃P W₁₂O₄₀· H₂O （5）.Complex4crystallizes in Orthorhombic, s pace group Pn ma, with the cellpara meter s of a=22.5183（6）, b=19.4689（5）, c=11.1149（3）, α=90°,β=90°, γ=90°, V=4872.8（2）3, Z=4. R₁（F）=0.0417, ωR₂（F²）=0.1131.Goof（S）=1.031. Compl ex4c rystallize s in Rho mbohedral, space group R3m,with t he c ell para meters of a=16.2682（12）,b=16.2682（12）, c=24.819（4）,α=90°,β=90°, γ=120°, V=5688.4（11）3, Z=6. R₁（F）=0.0715,ωR₂（F²）=0.1444, Goof（S）=1.088. Complex4and5for me d t wo-di mensionalfra me wor k via l ots of hydrogen-bonds. Bo t h o f t he m ha ve wea k ca p acity o fcatalytic eli mination on met h anol.4. Charge-trans fer comple x based on the struct ur e of As2M o6Combine d with hydr other mal met hod a n d s oluti on evapor ati on method,a charge-transfer complex with novel structure base d on As2Mo6wa ssynthsise d,（C2H8N）6（As2M o6O26）·4H₂O （6）. Complex6crystallizes intriclinic, space group P-1, with t he cell par a mete rs of a=8.6361（7）,b=11.2346（9）, c=12.2904（9）, α=70.441（2）°, β=70.943（3）°, γ=79.253（3）°,V=1058.07（14）3, Z=1. R₁（F）=0.0577, ωR2（F2）=0.1350. Goof（S）=1.006.This complex has excellent per for ma n ce wit h re versible photoc hromic a ndther mochr o mi c. At t he sa me ti me, co mpl ex6sh ows good per for ma nce in t heexperi ment of ther mal catal ytic eli mi nation of met hanol.