I nga wa o mua, ka mahi te whakakōkī mā te pāhekoheko tika ki ngā tauhohenga.I roto i te pünaha catalytic nocontact hou (NCCS), he takawaenga i hangaia e te kotahi tauhohenga catalytic hei takawaenga kia taea ai e te tauhohenga motuhake te haere tonu.Ko tetahi tauira ko te whakapouritanga o te ethylbenzene, kare e puta i te aroaro o te Au nanoclusters me te cyclooctene kua whakarewahia, engari ka tere haere i te wa e noho tahi ana nga mea e rua.Ko te epoxidation whiriwhiri a Au o te cyclooctene i hangaia te cyclooctenyl peroxy me te oxy radicals i mahi hei takawaenga ki te timata i te oxidation ethylbenzene.Ko tenei punaha whakakotahi i kaha ki te whakawhānui ake i te hua whakakata o Au.I tautokohia te tikanga tauhohenga e nga mahi kinetics tauhohenga me nga whakamatautau mahanga miro.Ka taea e te NCCS nga tauhohenga whakarara ki te haere me te kore herenga o nga hononga stoichiometric, e tuku ana i nga nekehanga hou o te herekoretanga i roto i nga tikanga whakangao-wairua waro-ahumahi.

I nga wa o mua, ka pahekoheko te whakakorikori ki nga tauhohenga (tauhohenga A) ki te whakatika i nga whakarereketanga herenga kua tohua e te tauhohenga.Hei tauira, i roto i te oxidation cobalt-catalyzed o alkylaromatics (1) ranei te Au-catalyzed epoxidation o cyclooctene (2), ka whakakorikori te whakakoi i te tangohanga o te ngota hauwai mai i te waiwaro hei timata i te tauhohenga.I roto i te tauhohenga mekameka tuwhena kore utu, ka uru te whakakorikori ki te wehewehenga homolytic catalytic o te here ngoikore i roto i nga kaikohiko ka honoa marietia, ka whakaatuhia ranei hei poke i roto i te ranunga tauhohenga (1, 3, 4).Ko etahi o nga hikoi i roto i te tauhohenga whakakorikori karekau pea e hiahia kia whakapiri tika ki te tïpako-whakakii ina ka taea te hurihanga o te tïpako e te hua i hangaia i nga hikoinga o mua (5-8).Heoi ano, ko enei tauhohenga ka herea e nga hononga stoichiometric i waenga i nga hikoinga.Hei tauira, i roto i te waikura Mukaiyama (ep) o te alkene, ka huri te whakakorikori i te whakahekenga patunga i roto i te tauhohenga A, penei i te isobutyraldehyde, me te hanganga stoichiometric o te epoxide (tauhohenga B) (9, 10).Ahakoa ka taea i runga i te maapono, kaore matou i te mohio ki tetahi tauira ko te mahi a te whakakorikori he whakaputa i te takawaenga S i te tauhohenga A, i reira ka mahi a S hei takawaenga ki te timata, ki te whakakorikori ranei i tetahi atu tauhohenga B hei utu mo te whakauru hei reagent stoichiometric. , i te mea kaore e whai hua te whakakorikori mo te tauhohenga B (Fig. 1).I roto i taua kaupapa, ka toro atu te awe o te whakakorikori ki tua atu i te whakakorikori tauhohenga A ki te mahi hoki i te tauhohenga B engari karekau he pa atu ki ona tauhohenga.Ka kiia tenei kaupapa he punaha catalytic nocontact (NCCS).I roto i te NCCS, ko nga whanui o te tauhohenga o nga tauhohenga A me B kaore e herea e tetahi hononga stoichiometric i waenganui i a raatau.He rereke tenei ki nga tauhohenga tandem.I roto i te ahumahi, he maha nga wa ka whakatauhia e te hononga stoichiometric he herenga ohaoha ki runga i te tukanga whakaputa matū.Ko tetahi tauira rongonui ko te hanga stoichiometric o te phenol me te acetone na roto i te waikura o te benzene ma te kumene hydroperoxide takawaenga i roto i te tukanga cumene (11).

Ko te whakakorikori (Cat) ka whakakorikori i te tauhohenga A (AR ➔ S ➔AP) e whai hua ana te takawaenga S ki te timata, ki te whakakorikori ranei i te tauhohenga B (BR ➔ BP), ahakoa ko te tauhohenga B karekau i te whakakorikori.

I kitea e matou he NCCS pera i te wa e tirotiro ana i nga ahuatanga catalytic o nga tautau Aun kua whakarewahia (kei te nuinga o te n e ono ki te waru ngota) mo te whakapouritanga o te ethylbenzene (EB).Kua whakaaturia e matou ko enei Aun kua whakarewahia i whakakorikori i te tiimatanga o te whakapooratanga o te cyclooctene (cC8═) me te O2 me te ~80% te whiriwhiringa (2).I hangaia enei tautau i roto i te waahi i te wa o te Au/SiO2-catalyzed cC8═ epoxidation, a ka mau tonu to ratou kaha ki te whakaputa i te radical initiator cyclooctene hydroperoxy radical (cC8═OO·) puta noa i te tauhohenga.Ka taea te kohia nga tautau Aun kua whakarewahia ki roto i te ranunga tauhohenga i muri i te tangohanga o te Au/SiO2, ka whakatauhia te rahi toharite ma te whakamahi i te karu irahiko whakatika-aberration me te spectroscopy fluorescence (2).I tua atu i nga tautau Aun, kei roto ano i enei ranunga te cyclooctene hydroperoxide (cC8═OOH) me nga hua waiora cyclooctene epoxide, cyclooctenol, me cyclooctenone.Ko te cC8═OOH te ahua hauwai o cC8═OO· me te noho ki te kuhanga o te 0.2 ki te 0.5 M i muri i te 40 ki te 100% te huringa cC8═.Ko tenei ranunga ka kiia ko Au + cC8═OOH-x, ko x te ōrau o te huringa cC8═.Ahakoa he tino puhoi me te roa (>5 haora) te wa whakaurunga, ka taea ano te whakahaoratanga cC8═ ma te whakahaora-aunoa kaore he tautau Aun.Ko nga ranunga ka puta mai i te waikura-aunoa kaore he Au ka kiia ko cC8═OOH-x.I roto i te NCCS, ko te Aun kua whakarewahia te whakakorikori, ko te whakapooratanga o cC8═ ko te tauhohenga A, ko te cC8═OO· ko S.

Ko te whakapouri-aunoa o te EB kare e puta tere.I te 145°C, 9% anake te tauhohenga i puta mo te EB pai i raro i te 2.76 MPa O2 (12).I raro i o maatau ahuatanga ngawari ake o te 100°C me te O2 e pupuhi ana i te 0.1 MPa, karekau he tauhohenga o te EB pai mo te 20 haora neke atu.Ko te taapiri i te kaikawe tuwhena kore utu i hiahiatia kia haere tonu tenei tauhohenga.Ko te timatanga me te 2,2′-azobisisobutyronitrile (AIBN), he tino whakakorikori waiariki, i puta mai te whakamaarama-aunoa o te EB me te roa o te mekameka toharite o ~3 (piki S2A).I kitea he mekameka poto ake (~1) ma te whakamahi i te tert-butyl hydroperoxide (whakaahua S2B), he iti rawa te tauhohenga e kitea ana ma te whakamahi i te kumene hydroperoxide iti rawa.No reira, he iti te awe o te whakahaora-aunoa o te EB ki nga hua tauhohenga e whakaatuhia ana i raro nei.

I tutuki te waiora aerobic o EB ki te EB hydroperoxide, acetophenone, me te phenylethanol ma te taapiri i te Au + cC8═OOH-50 kei roto he ranunga o Aun, cC8═OOH, me cC8═ korekore (Fig. 2, curve 1).I whakaatuhia e nga whakamatautau e whai ake nei, ko enei waahanga e toru i whai waahi nui ki te whakapouritanga EB, a ka hono ki te whakakorikori, S, me te AR i roto i te punaha NCCS e whakaatuhia ana i te Whakaahua 1.

(i) 7 ml o EB + 3 ml o Au + cC8═OOH-50;(ii) 7 ml o EB + 3 ml o Au + cC8═OOH-50 + 1.2 mmol PPh3;(iii) 7 ml o EB + 3 ml o Au + cC8═OOH-99 + 0.6 mmol PPh3;(iv) 7 ml o EB + 3 ml o cC8═OOH-50;(v) 7 ml o EB + 3 ml o cC8═OOH-50 + 1.5 mmol PPh3.Ko te rahinga o te PPh3 i tapirihia i whakaritea kia rite ki te rahinga o te hydroperoxide (te pāmahana tauhohenga, 100°C).

I raro i o maatau tikanga, karekau he hauora EB aerobic i kitea i roto i te ranunga o cC8═ me EB (arā, kaore he Cat, S ranei).Ko te Triphenylphosphine (PPh3) he tino whai hua ki te tango i te hydroperoxides.He otinga Au + cC8═OOH-99, kua pau te cC8═OOH na te taapiri PPh3, kei roto ko Aun me te iti rawa o cC8═ kaore i tauhohe, i rahua te tauhohenga EB ahakoa i muri i te 2 haora (Fig. 2, curve 3), e tohu ana ko Aun ko ia anake kaore i whai hua.I tohu ano tenei hua ko etahi atu hua o te oxidation cC8═, penei i te cyclooctene epoxide, te waipiro cyclooctene, te ketone ranei, kaore i kaha ki te timata i te waiora EB.He rereke ki te whakamatautau i runga ake nei, ko te tango i te cC8═OOH me te PPh3 mai i Au + cC8═OOH-50, ka mahue a Aun me te cC8═ korekore, kaore i aukati i te huringa EB (whakaritea nga pihi 1 me te 2, Fig. 2).

Ko enei huinga raraunga e toru e whakaatu ana i te whakakotahitanga i waenga i a Aun me cC8═ kaore i tauhohe i te timatanga o te waikura EB.I whakapae matou na Aun i whakakorikori te waikura o cC8═ ki te hanga cC8═OOH, koinei te kaitaunaki o te tauhohenga EB.Ka taea tenei te whakamatautau ma te whakatairite i te pai o te tiimata o te waikura EB me te ranunga o cC8═OOH me cC8═ engari kaore he Aun i mua i muri i te tangohanga o cC8═OOH me te PPh3.Kia pai ai te whakatauira i nga ahuatanga o nga huinga whakamatautau o mua, i whakamahia e matou te otinga cC8═OOH-50 mo te ranunga o cC8═OOH me cC8═ kia puta ai nga hua ka puta mai i nga hua whakahaora cC8═.Ko nga hua i whakaatu i te aroaro o cC8═OOH-50, he pai te whakautu a EB (Fig. 2, curve 4).Heoi, ki te tangohia cC8═OOH e PPh3, karekau he tauhohenga mo te haora tuatahi ka pehia te mahi i muri mai (piko 5).I tautoko ano enei raraunga i te tauira ko te mahi a Aun he whakaputa tonu i te cC8═OOH ma te cC8═ oxidation, a cC8═OOH i timata te tauhohenga EB.Ko te mahi catalytic a Aun i whakapumautia ake ma te kite ko nga reiti tuatahi o te waiora EB i te kore cC8═OOH i piki ake me te piki haere o te kukume Aun (piki S3).

Ko te mahi ahurei a Aun i roto i tenei NCCS i whakaatuhia ma te tirotiro i a Co hei whakakorikori rereke, i whiriwhiria na te mea ko te acetate cobalt me ​​te cobalt cycloalkanecarboxylate (13) he whakakorikori ahumahi mo te hurihanga o te EB ki te acetophenone me te molecular O2, e mahi ana i raro i nga tikanga kino me te hiahia te aroaro o te waikawa me te katote bromide.Ka whakamahia hoki nga matatini Co mo te waiora EB aerobic whiriwhiri i te aroaro o te organocatalyst N-hydroxyphthalimide (NHPI) ranei he reductant patunga tapu (14, 15).Heoi, i raro i o maatau tikanga tauhohenga, ko te noho mai o Co/ZSM-5 karekau i puta he waioratanga o te EB, cC8═, te ranunga ranei mo te iti rawa i te 6 haora.Arā, karekau i taea e Co anake te kōkiri i te tauhohenga hāora.Heoi, i te aroaro o Aun me cC8═, i whakaaheitia nga tauhohenga waiora.I runga ano i te ahua, cC8═ ranei EB i toru ki te rima nga wa tere ake i te wa e noho ana a Co/ZSM-5, me te whakanui ake i te nui o Co/ZSM-5 (tepu S2, nga whakamatautau 6 ki te 8).I rereke ano te tohatoha hua o te EB i te aroaro o Co/ZSM-5.Ko te whakanui ake i te nui o Co/ZSM-5 ka piki ake nga hua acetophenone, a, ki te iti ake, ka puta te phenylethanol i te utu o te EB hydroperoxide (tepu S3, nga whakamatautau 6 ki te 8), e rite ana ki te meka na Co i whakakorikori i te pirau o te EB hydroperoxide ki te acetophenone me te phenylethanol me te waikuratanga o te mea whakamutunga ki te acetophenone.Mo te pai, i whakauruhia e matou a Co/ZSM-5 ki roto i ta matou ranunga tauhohenga hei whakapoto i te wa tauhohenga.

Ko tetahi take wehewehe i waenga i te NCCS me nga punaha tauhohenga tandem ko te mea i mua, kaore he hononga stoichiometric i waenga i nga tauhohenga A me B (Fig. 1).Hei whakamana i puta a maatau tauhohenga ma te NCCS, i whakamatauria e matou te paanga o te whakarereke i te owehenga o cC8═ ki EB ma te aro turuki i o raatau reeti tauhohenga takitahi.E whakaatu ana te Whakaahua 3 i nga hua o te whakarereke i te kukū cC8═ tuatahi i te wa e mau tonu ana te kuhanga EB tuatahi me etahi atu tikanga tauhohenga.Ko nga raraunga e whakaatu ana karekau he hononga stoichiometric pumau i waenga i nga rahinga o nga tauhohenga e rua i tauhohe, e whakau ana he rereke te tauira tauhohenga mai i te kaupapa tauhohenga tandem tuku iho.He huinga whakamätautau e rite ana i rerekë ai ngä kuhanga tuatahi o te EB i te wa e whakatika ana i ëtahi atu kuhanga ka tae ki te whakatau kotahi.Mai i enei raraunga, i tatauhia nga reiti tauhohenga tuatahi (Ripanga 1 me te ripanga S2, nga whakamatautau 4 me 5) ka whakaatuhia he rereke rereke mo cC8═ me EB.Karekau he tauhokohoko i roto i nga reiti tauhohenga i waenga i nga tauhohenga e rua na te mea ka tere ake te haere o tetahi hohenga, me puhoi te ahua o tetahi.Ka piki ake nga reiti tauhohenga e rua i te wa kotahi, e ai ki nga whakamatautau 4 me te 5 i te ripanga S2.Ka taea te hoko atu mena ka whakataetae a EB me cC8═ mo te waahi tauhohenga catalytic rite, takawaenga ranei.He rite ano tenei whakatau ki te mea ko nga tauhohenga tukutahi o te EB me te cC8═ karekau he paanga iti rawa ranei ki o raatau tohatoha hua, penei i te Ripanga 1 me te ripanga S3.

Ko nga kohinga cC8═ tuatahi ko 0.34 M (A), 1.05 M (B), me te 1.75 M (C).I whakamahia te Decane hei hanga i nga rereketanga o te rōrahi o te cC8═ i whakamahia.Ētahi atu tikanga: 32 mg o Co/ZSM5, 100°C.

Ko enei raraunga e rite ana ki te kaupapa miihini e whakaatuhia ana i te Whakaahua 4, e whakanuihia ana nga waahanga nui mo te NCCS me te whakaatu i nga kaitakaro matua (he kaupapa tino pai kei te whakaatu i te pikitia S8).I roto i tenei tikanga, ka timata nga tautau Aun i te huringa epoxidation cC8═ ma te whakaputa i nga rauropi cyclooctenyl (I) me cyclooctene peroxy radicals (II).Ka uru atu enei tuwhenawhe e rua ki roto i te huringa epoxidation cC8═, pera i whakaritea i mua (2, 16).I te wa e noho ana a EB, ka noho a II hei ngota ngota takawaenga me te whakawhiti i waenga i te huringa whakahaora cC8═ me te huringa hāora EB.I roto i te huringa EB, ka tauhohe a II me te EB ki te hanga i te tuwhenawhe phenylethyl, ka hanga tonu he phenylethyl peroxy radical (III) ma te tauhohenga ki te O2, i te mea e mohiotia ana he tino ngawari nga tauhohenga tuwhena-wao me te O2 (1).Ko te tangohanga hauwai i muri mai na III ka hanga te phenylethyl hydroperoxide ka mutu ko te acetophenone me te phenylethanol.Ka taea hoki e III te urupare tere ki te cC8═, ka noho hei huarahi ki te whakaki i te II ka pau i te huringa hāora EB.No reira, karekau te tauhohenga waiora EB e haere tahi me te whakakorenga stoichiometric o te tauhohenga epoxidation cC8═, karekau he "whakawhitiwhiti" i roto i nga reiti tauhohenga o EB me cC8═ pera me te mea kua whakataetae ratou mo te reagent kotahi. pae kaha catalytic ranei.Na te mea ka uru a II ki te hikoi timatatanga i roto i nga huringa hāora EB me cC8═ engari kaore i te tika i roto i nga hikoi hanga hua, ko te hono o nga tauhohenga e rua kaore e pa ki nga tohatoha hua.

Ko te Cyclooctene peroxy radical (II) te kaitakawaenga matua e timata ana i te waiora EB.Ka taea te whakaora II ma te tauhohenga o te EB peroxy radical (III) me cC8═.Kei te taha maui ki runga, ka timata nga tautau Aun i te huringa whakahaora cC8═ (huringa kei te taha maui).Ko te hurihanga kei te taha matau e whakaatu ana i nga hikoinga mo te waiora EB.Ko nga hikoinga matua anake mo te NCCS ka whakaatuhia.

Hei manatoko i te hanganga o nga takawaenga tuwhena noa e whakaarohia ana i te Whakaahua 4, ka taapirihia e matou te mahanga miro 5,5-dimethyl-1-pyrroline N-oxide (DMPO) ki te ranunga tauhohenga hei hanga i te roanga o te nitroxide radical spin adducts me te Ko nga rauropi kore utu kei te kitea me te X-band electron paramagnetic resonance (EPR) spectroscopy.Hei mana whakahaere, kaore he rauropi i mauhia e DMPO i roto i te otinga o te acetone me te decane kaore he C8═, EB ranei (piki S4-3).I te whakaurunga o te DMPO ki te ranunga tauhohenga kei roto cC8═OOH me cC8═ (whakaahua S4-1), he pai te whakatairite i te awhiowhio EPR ka puta hei huinga o tetahi momo paramagnetic motuhake (A i te ahua, ~86% o te katoa te kaha whaihanga) me nga momo iti e rua (B me C, ~ 5 me ~ 9% o te katoa o te kaha whaihanga, ia), e whakaatu tika ana mo te hanganga tuwhena i te wa o te tauhohenga.I runga i te whakatauritenga o nga uara hono honohono ki era o nga taapiri DMPO e mohiotia ana (tepu S1), ka tohua nga momo C ki te taapiri DMPO/ROO•, ko te cyclooctene 3-peroxy radical (II) e whakaahuatia ana hei takawaenga i waenganui i nga mea e rua. tauhohenga (Fig. 4).Ko te momo A me te B i tohua ki etahi taapiri DMPO/RO• e rua paku rereke, i reira ka korero a R ki tetahi waahanga waiwaro.Ko ratou pea ko tetahi o nga momo RO• kua whakaahuatia i te Whakaahua 4, i nga rauropi alkoxy ranei i puta mai i te DMPO/ROO• te pirau taapiri [DMPO/ROO• e mohiotia ana he kore iu nga taapiri ka pirau ki te taapiri alkoxy radical e rite ana (17, 18)] he ranunga ranei o nga mea e rua.I te wa i whakaurua ano te EB ki roto i te ranunga tauhohenga, he pai te whakataurite i te awhiowhio EPR i puta mai me te nuinga o nga momo A′, he tino rite ki nga momo A (DMPO/RO•), me nga momo iti e rua B me C he rite nga takoha iti. (whakaahua S4-2 me te ripanga S1).I te mea ko te whakaurunga o te EB i tika kia peia te hanganga o te phenylethyl peroxy radicals (III), ko te momo A′ pea he ranunga o te RO• i hangaia i roto i te tauhohenga tae atu ki tetahi taapiri phenylethyl peroxy, i muri ka pirau ki te taapiri o te phenylethyl oxy DMPO.

Ma te whakamahi i te EB-d10 hei tauhohenga me te aro turuki i te tapanga deuterium i roto i nga hua cC8═ ka kitea mena he tauhohenga a EB me nga tuwhena waro cC8═.Ko nga hua o taua whakamatautau i whakaatu kaore he kaporeihana deuterium i roto i te cyclooctene epoxide (piki. S5 me S6).Ko te Phenylethanol i pupuri i te katoa o te deuterium i roto i te EB reactant, a ko etahi o nga deuterons i roto i te roopu methyl o te acetophenone kua whakawhiti, ka puta pea i te spectrometer papatipu.No reira, karekau he taunakitanga o te tauhohenga i waenga i te EB-d10 me te cyclooctenyl radical, ka whakaurua te deuteron ki roto i nga hua cC8═.

Ko te whakamahinga o te rautaki NCCS i whakawhānuihia ki te tirotiro i te Au + cC8═OOH-100-awhina waiora aerobic o 4-methylanisole.Na te kaha ake o nga hononga C─H tuatahi i roto i tenei ngota ngota, i whakahaeretia te tauhohenga oxy-functionalization i te pāmahana teitei ake.Ko nga reiti tuatahi o te hurihanga o te 4-methylanisole ki te 4-anisaldehyde i whakatairitehia mo nga tauhohenga i timatahia me Aun me te taapiri cC8═ ranei (cC8═OOH i tangohia me te PPh3).He rite ki te hāora EB, i te mea karekau he cC8═ i roto i te ranunga tauhohenga me te kore cC8═OOH, he puhoi te tere o te waikura tuatahi (piki S7).I te taapiringa cC8═ ki te ranunga tauhohenga, ka tino piki ake te tere o te waikura tuatahi.No reira, i taea e nga tautau Aun te whakaputa cC8═OOH mai i te cC8═ kua tapirihia hei timata i te waikura o te 4-methylanisole pera i te tumanako i roto i te NCCS.

Hei whakamutunga, kua whakaatuhia e matou te kaupapa o te NCCS.Ma te whakamahi i te oxidation tukutahi o te cyclooctene me te EB tae atu ki te cyclooctene me te 4-methylanisole, i whakaatuhia te NCCS ki te whakaahei i te whakakotahitanga o te waiwaro me te kore nga herenga hononga stoichiometric o nga tikanga tukutahi o te waikura.Ka whakawhiwhia e tenei he tohu herekore i mua i nga mahi ahumahi kia kore ai e herea te ohanga ohaoha e te hiahia mo nga maakete pai mo nga hua takirua i hangaia i roto i nga moni stoichiometric.

Ko nga puna me te maatanga o nga matū i whakamahia ko enei e whai ake nei: HAuCl4•3H2O (≥99.9% te turanga konganuku tohu, Sigma-Aldrich), silica fumed (CAB-O-SIL90, Cabot Corporation), ethylenediamine (≥99% ReagentPlus, Sigma-Aldrich) , waihā (200 kōeke, Decon Labs), cobalt(II) pākawa hexahydrate (≥98%, Sigma-Aldrich), Nano H-ZSM-5 (P-26, ACS Material), decane (≥99% ReagentPlus, Sigma- Aldrich), dodecane (≥99% ReagentPlus, Sigma-Aldrich), cis-cyclooctene (95%, Alfa Aesar), EB (99.8% anhydrous, Sigma-Aldrich), EB-d10 (99 atomic % D, Sigma-Aldrich) , 4-methylanisole (99%, Sigma-Aldrich), acetophenone (99% ReagentPlus, Sigma-Aldrich), 1-phenylethanol (98%, Sigma-Aldrich), hydrogen peroxide (30% wairewa wai, Fisher Chemical), pāhare pāporo. (koeke reagent, 90%, Sigma-Aldrich), konutai pūkawa (Food Chemicals Codex/United States Pharmacopeia–grade, Fisher Chemical), tetrahydrofuran (>99%, Sigma-Aldrich), tert-butyl hydroperoxide (~5.5 M in decane , Sigma-Aldrich), PPh3 (>98.5%, Sigma-Aldrich), d-chloroform (99.8 atomic % D, Sigma-Aldrich), HCl (38% w/w, Fisher Chemical), HNO3 (68 ki te 70% w /w, Fisher Chemical), EM Quant peroxide whakamātautau, me te syringe tātari (polyvinylidene difluoride membrane, 0.25 mm/0.2 μm, Acrodisc).

Au/SiO2.Ko te whakakōkī nanoparticle koura e tautokohia ana e te silica me te Au(en)2Cl3 precursor kia rite ki te tikanga i whakawhanakehia e Zhu et al.(19) ka whakarereketia e Qian et al.(2).Ki te whakamaarama ake, i whakaritea he wairewa Au(III) chloride trihydrate ma te whakakore i te 0.5 g o HAuCl4•3H2O i roto i te ranunga kei roto 10 ml o te waihano me te 2 ml wai.Whai muri i te hanga i te wairewa riterite, 0.23 ml o te ethylenediamine (en = ethylenediamine) i tapirihia ki te wairewa topata iho hei hanga Au(III) ethylenediamine chloride [Au(en)2Cl3] ma te whakawhiti ligand.I kohia te Au(en)2Cl3 i hangaia ma te filtration ka horoi ki te 300 ml o te waihano.Hei whakatakoto i te Au ki runga i te tautoko silica, i whakaritea he wairewa wai 4.2 mM Au(en)2Cl3 ma te whakakore i te 46.3 mg o Au(en)2Cl3 ki roto i te 26 ml o te wai whakaheke iona (DDI).Ko te otinga i hangaia i te 40°C i roto i te pati hinu.Katahi ka tapirihia te 1 g o te silica fumed ki te wairewa whakamahana i te wa e whakakorikori ana.I te rukuhia nga tautoko silica katoa ki te wairewa, ka tangohia te ranunga mai i te pati hinu, ka whakamatao ki te pāmahana rūma.Na roto i te whakatikatika i te pH o te ranunga ki te 9 me te taapiri maturuturu o te 0.75 M en wairewa wai, he pai ake te whakaurunga o nga kohinga koura cationic ki te mata kino kua tutuki.I muri i te whakaoho mo te 2 haora i te pāmahana rūma, ka tātarihia te ranunga ka horoia ki te 500 ml o te wai DDI.Hei tango i nga toenga kore (Cl, en, etahi atu poke), ka marara ano te keke tātari ki te 200 ml o te wai DDI i te 40°C.Ko te whakamutunga, ko te Au/SiO2 i hangaia ma te filtration ka horoi ki tetahi atu 500 ml o te wai DDI ka whakamaroke ki te hau mo te po.Ko te whakamaaramatanga o te whakakorikori nanoparticles koura e tautokohia ana e te silica i mahia i roto i te ngongo U i raro i te rere O2/O3 (~ 300 ml/min) me te tere ramping o 0.12°C/min tae noa ki te 150°C.I penapenahia te whakakorikori ki te pouri i te 5°C.Ko te utaina koura, he mea ine te inenga ma te whakaurunga inductively plasma optical emission spectrometry, he 1.2 te taumaha % (wt %), a ko te rahi o te matūriki koura toharite i inehia ma te matawai karapa hiko hiko (STEM) tata ki te 2 nm.

Co/ZSM-5.Ko te Nano H-ZSM-5 i calcined i roto i te U-tube i raro i te rere O2/O3 (~ 300 ml/min) me te tere ramping o 2°C/min tae noa ki te 200°C ka mau ki te 200°C mo te 1 haora ki te tango. tauira toenga.Ko te Co/ZSM-5 i whakaritea e te makuku tuatahi.Hei tauira, he 5 wt % te uta Co/ZSM-5 i whakaritea ma te taapiri i te wairewa 0.72 M cobalt (II) nitrate [250 mg o te cobalt(II) nitrate hexahydrate i roto i te 1.2 ml o te wai DDI] ki te 1 g nano H- ZSM-5 i te ata hurihuri i te ipurau.I whakamarokehia te slurry i raro i te rama, ka hanga he paura mawhero rite.Ka utaina te paura i hangaia ki roto i te ngongo whakamaarama tika ka purea i raro i te rere argon (100 ml/min) mo te 1 haora hei whakaiti i te makuku.Ko te whakakorikori kua oti te whakarite ka whakateohia i raro i te rere o te hāora (60 ml/min) me te tere ramping o 10°C/min ki te 450° (ka mau ki te 250°C, 350°C, me te 450°C mo te 1 haora ia) .Ko te Co/ZSM-5 kua whiwhi he 5 wt % te uta o te cobalt.E rua atu nga uta, 3 me te 7 wt %, i whakaritea ano.Ko nga whakakorikori e toru e tohuhia ana e te H2 te whakaiti i te pāmahana-programmed, te rereketanga x-ray, x-ray photoelectron spectroscopy, me te ultraviolet-visible spectroscopy.

Au-kei roto filtrate.Ko te filtrate Au-kei roto (Au + cC8═OOH-x) i roto i te waahi i hangaia mai i te Au/SiO2-catalyzed cC8═ tauhohenga epoxidation rite ki te tukanga i whakawhanakehia e Qian et al.(2) I mua i te tauhohenga, i purea te cC8═ ki te tango i te whakapumau kua taapirihia e te kaihanga.I te nuinga o te waa, 50 ml o te wairewa pāhare pāporo 3 M (KOH) i tāpirihia ki te 50 ml o cC8═ i roto i te ipu.Whai muri i te pai o te ranu me te whakakorikori kaha, ka kohia te paparanga waro ma te wehewehe.I tukuna ano tenei mahi me tetahi atu 50 ml o te 3 M KOH me etahi atu e rua 50 ml o te wai DDI.Ka whakamarokehia te cC8═ ki te konutai pūkawa ngāwha i te pō.Hei tango katoa i te whakapumau, ka whakamarokehia te cC8═ kua maroke ki roto i te pati hinu i te takiwa o te 180°C, ka kohia te hautanga i puta i te 145°C.Ko te cC8═ (10 ml) me te decane (1 ml) kua purea i konatunatua ki roto i te reactor kei roto 80 mg o te whakakorikori Au/SiO2 kua kiia ake nei.Ko te tauhohenga cC8═ epoxidation i whakahaerehia i raro i te rere o te oxygen (30 ml / min) i te 100 ° C, a, i aroturukihia te huringa e te GC.Kia tae ki te huringa e hiahiatia ana, ka kohia te ranunga tauhohenga me te whakakorikori totoka i tangohia e te tātari wera ma te whakamahi i te tātari syringe.Ko te kukū Au tino whakarewahia i whakatauhia e te inductively connected plasma mass spectrometry he tata ki te 80 ng/ml, a ko te rahi o te kahui Au i whakatauhia e te hihinga orooro me te karato irahiko tuku aberration-whakatika mai i nga ngota Au ki ~0.7 nm.Ko cC8═OOH-x he rite tonu te whakarite me te kore whakamahi i te whakakorikori Au/SiO2.Ko nga otinga Au + cC8═OOH-x me cC8═OOH-x kei roto nga hua waikura cC8═, kei roto ko te cyclooctene oxide, cyclooctene 3-hydroperoxide, 2-cycloocten-1-ol, 2-cycloocten-1-one, me nga moni o 1,2-cyclooctanediol.

Te tukanga whānui.I whakahaeretia nga tauhohenga waiora EB i roto i te pouri i roto i te reactor porotakaro kaki-toru kua mau ki te ngongo whakamarara karaehe pai (Chemglass Life Sciences) me te kaitao e mau tonu ana ki te -10°C.I roto i te tauhohenga angamaheni, 7 ml o te EB, 1 ml o te decane, me te 3 ml o te filtrate (Au + cC8═OOH-x or cC8═OOH-x) i utaina ki roto i te reactor me te whakakorikori autō kua pania ki Teflon.Mena ka whakamahia, 32 mg o 5% Co/ZSM-5, mena kaore i tohua, ka taapirihia.I muri i te huinga o te huinga tauhohenga, i whakapumautia te ranunga tauhohenga i raro i te rere N2 mo te 20 meneti i roto i te pati hinu kua whakamahana.I te wa i whakapumautia ai te mahana o te condenser me te pati hinu, ka tukuna he rere O2 tonu i te 30 ml/min.Ko te ranunga tauhohenga (0.1 ml) i tangohia i etahi wa rereke mo te tātari (i whakamahia te tātari syringe i te wa i uru mai ai nga whakakorikori totoka), ka rewa ki te 0.7 ml o te d-chloroform, ka tātarihia e te 1H karihi autō autō (NMR).

Te tautuhi hua me te ine.Ko nga wahanga o te ranunga tauhohenga i waimeha ki te tetrahydrofuran, ka tātarihia e te hau chromatography–mass spectrometry (GC-MS; Agilent GC-7890A, MS-5975).Mo te tauhohenga EB, i kitea ko te acetophenone me te 1-phenylethanol nga hua tino nui.Ko te 1H-NMR me te 13C-NMR (400 MHz Agilent DD2-MR400 pūnaha) i whakamahia hei whakaū ake i ngā tuakiri hua.Ko te 1-Phenylethyl hydroperoxide, kaore i kitea e GC-MS na te kore o te waiariki, i tohuhia e te NMR ko tetahi atu hua nui.Ko nga hua e toru i inehia e te 1H-NMR ma te whakamahi i te decane hei paerewa o roto (whakaahua S1).I whakatauhia te mate whakaetonga ka whakamahia ki te whakatika i nga kohinga hua.Whai muri i te whakatikatika i nga ngaronga whakaetonga, karekau he taurite waro i kitea mo te tauhohenga EB.Mo te tauhohenga cyclooctene, cyclooctene oxide, cyclooctane-1,2-diol, 2-cycloocten-1-ol, me te 2-cycloocten-1-one i inehia e te GC.Ko te Cyclooctene 3-hydroperoxide kaore i pumau, ka pirau i roto i te pou GC na reira kaore i kitea.Tata ki te 10% te ngaronga waro i te huringa katoa ahakoa i muri i te utunga mo te mate whakaetonga, ka taea te whakamarama ma te hanga o te iti o nga hua tino waikura kaore i mohiotia.

Te hurihanga me te whiriwhiringa tatauranga.Ko te GC, ko te NMR rohe ōwehenga o te rāpoi ngota o te paanga ki te decane paerewa o roto i whakamahia hei tatau i te hurihanga me te whiriwhiringa.Ahakoa i whakamahia he kaitao whakamahana, he mea tika ki te utu mo te mate whakaetonga na te nui o te pāmahana tauhohenga me te roa o te tauhohenga.I whiwhi nga pihi whakatika whakaetonga mo te EB me te cC8═ i raro i te hauota rere, ka whakatauritea ki te ōwehenga o te EB/decane, cC8═/decane ranei.Na te mea he rite nga ira koropuputanga o EB me cC8═, ko nga tauwehe whakatika i puta ko te 0.0044 (kua heke te ōwehenga i ia haora).

Te inenga o te hydroperoxide.I inehia te kukū o te hydroperoxide e rua nga tikanga titration:

1) Te titration Triphenylphosphine (PPh3).I whakamahia te PPh3 (0.1 M i te EB) ki te tarai i nga tauira hydroperoxide e kore e mohiotia, ka tohua te pito mutunga ki te EM Quant peroxide test strip.I whakamahia te 31P-NMR hei whakaū i te tango katoa o nga momo hydroperoxide.

2) Te titration Iodometric.Ko te tauira (0.2 ml) i konatunatua ki te 1 ml o te CHCl3/acetic acid (v/v = 1:2) me te 6 ml o te otinga 1 M KI.I whakakorikoria te ranunga i roto i te pouri mo te 2 haora, katahi ka titrated ki te 0.005 M Na2S2O3 i te aroaro o etahi pata wairewa māngaro.I tae ki te mutunga ka kore te tae o te ranunga.

Ko nga tikanga e rua i rite ki roto;heoi, he rereke o raatau hua ma te 5 ki te 10%.Na te mea ko te Au + cC8═OOH-x me te cC8═OOH-x i whakamahia i roto i tenei kaupapa i hangaia na roto i te waikura cC8═OOH-i timatahia, he rereke te kuhanga o te hydroperoxide mai i te puranga ki te puranga engari kei roto tonu i te awhe 0.2 ki te 0.5 M mo nga mea hou kua rite. cC8═OOH-40 ki cC8═OOH-100 tauira.Ka heke haere te kukū o te hydroperoxide i te wa o te rokiroki.

Ko nga whakamatautau mahanga a EPR.I whakauruhia te DMPO (23 μl) ki te 1 ml o te tauira kia tae ki te kohinga DMPO o 0.2 M, me te 20 mg o Co / ZSM-5 i whakauruhia ki te ranunga tauira i roto i te ipuipu whakamatautau.I sonicated te ranunga mo te 1 min ki te whakatārewa i te whakakōkī, a ka whai i tenei i te whakamahana i te 60°C mō ~10 min.I whakawhitia tetahi wahi o te ranunga ki roto i te ngongo capillary ngongo ngongo borosilicate porowhita (1.50 roto diameter × 1.80 te whanui o waho, Wale Apparatus), kua hiritia ki tetahi pito—katahi ka tuu tenei ngongo ki roto i te ngongo EPR Wilmad quartz X-band ( Sigma-Aldrich).I whakatio te tauira ma te rumaki i te ngongo EPR ki te wai N2.I mua tonu i te ine i te hihinga EPR, ka rewa te tauira.I mahia nga inenga ngaru-ngaru (CW) X-band EPR i te pāmahana rūma i runga i te momo rerekee E-4 spectrometer ma te whakamahi i te maihao Dewar.

Te whakamatautau tapanga Isotopic.I whakamahia te Deuterated EB (d10-EB) i roto i te whakamatautau o te ranunga o te 6 ml o cC8═OOH-45, 5 ml o d10-EB, 1 ml o te decane, me te 60 mg o Co-ZSM-5 (7%) , i te 120°C, me te 6 ml o cC8═OOH-45, 5 ml o EB-d10, me te 1 ml o te dodecane.Hei whakaea mo te hekenga o te tere o te tauhohenga na te awenga o te wetewete iraiti, i mahia te whakahaoratanga i te teitei ake o te 120°C.I tangohia nga waahi o te tauira i mua i muri mai i te 24 haora o te tauhohenga me te tātari e 2H-NMR me GC-MS.

Ko te 2H-NMR spectrum (fig. S5, spectrum 2) i whakaatu i etahi tihi hou i muri i te tauhohenga, kaore i mua i te tauhohenga, i te δ1.50, δ1.58, δ4.94, δ7.42 ki te δ7.72, me te δ8.04 .Na te iti o te J-hononga me te ngawari o te 2H-NMR, kaore i whakatauhia nga tauira wehewehe.Ko nga tihi i te δ8.04 me te δ7.42 ki te δ7.72 i tohua ki nga deuterons o te mowhiti kakara o te acetophenone;ko nga tihi i te δ1.50 me te δ4.94 i tohua ki te methyl me te benzylic deuteron o 1-phenylethanol, ia;a ko te tihi i te δ1.58 i tohua ki te deuteron i D2O i hangaia mai i te pirau hydroperoxide.Karekau he deuteron i kitea e hono ana ki nga hua o te cyclooctene epoxidation, a ko te hanga o te wai whakaheke i tohu ko nga kaikawe mekameka tuwhena tino nui i roto i te tauhohenga whakahiato-tahi he peroxy me te alkoxy.

GC-MS spectra o nga hua e whakaatuhia ana i te piki.S6.Ko te Acetophenone-d8 (m/e 128, kua whakakorea katoatia, fig. S6A, m/e 127 me 126) i kitea.Mai i te tauira pakaru, ko nga whakawhitinga HD katoa i puta i te waahi methyl.I tua atu, ko te 1-phenylethanol-d9 (m/e 131) (fig. S6B) anake nga hua kua whakakorehia i kitea.Karekau he deuterium i kitea i roto i te cyclooctene oxide (fig. S6C), te hua tino nui mai i te cyclooctene epoxidation.Ka taea te hanga 1-Phenylethanol-d9 mai i te tauhohenga o te tuwhenawhe phenylethoxy me te cyclooctene.

Kei te waatea nga rauemi taapiri mo tenei tuhinga i http://advances.sciencemag.org/cgi/content/full/6/5/eaax6637/DC1

Whakaahua S5.2H-NMR i mua i te (tuhinga 1, whero) me muri i (tuhinga 2, matomato) 24-haora tauhohenga whakahaoratanga.

Whakaahua S7.Ko te whakatairite o nga huringa tuatahi o te 4-methyl anisole i timata ma te whakamahi i te Au + cC8═OOH-100, me te cC8═OOH i tangohia.

He tuhinga uru tuwhera tenei ka tohatohahia i raro i nga tikanga o te raihana Creative Commons Attribution-NonCommercial, e whakaae ana ki te whakamahi, ki te tohatoha, ki te whakaputa uri i roto i tetahi kaupapa, mena karekau te hua ka puta mo te painga arumoni me te tika te mahi taketake. whakahua.

FAKATOKANGA: Ka tono noa matou i to wahitau imeera kia mohio ai te tangata e taunaki ana koe mo te wharangi kei te pirangi koe kia kite ratou, ehara hoki i te mēra paraurehe.Kaore matou e hopu i tetahi wahitau imeera.

Na Anyang Peng, Mayfair C. Kung, Robert RO Brydon, Matthew O. Ross, Linping Qian, Linda J. Broadbelt, Harold H. Kung

I roto i te pünaha catalytic noncontact, nga takawaenga i ahu mai i te Au-catalyzed cyclooctene epoxidation ka pa ki te oxidation ethylbenzene.

Na Anyang Peng, Mayfair C. Kung, Robert RO Brydon, Matthew O. Ross, Linping Qian, Linda J. Broadbelt, Harold H. Kung

I roto i te pünaha catalytic noncontact, nga takawaenga i ahu mai i te Au-catalyzed cyclooctene epoxidation ka pa ki te oxidation ethylbenzene.

© 2020 American Association for the Advancement of Science.Katoa nga mana.Ko AAAS te hoa o HINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef me COUNTER.Science Advances ISSN 2375-2548.