Na omenala, ihe na-akpali akpali na-arụ ọrụ site na mmekọrịta ya na ndị reactants.N'ime sistemụ catalytic ọhụrụ na-adịghị emekọrịta ihe (NCCS), ihe etiti nke otu mmeghachi omume catalytic mepụtara na-eje ozi dị ka onye na-emekọrịta ihe iji mee ka mmeghachi omume nọọrọ onwe ya gaa n'ihu.Otu ihe atụ bụ oxidation nhọrọ nke ethylbenzene, nke enweghị ike ime n'ihu ma ọ bụ solubilized Au nanoclusters ma ọ bụ cyclooctene, mana ọ gara n'ihu ngwa ngwa mgbe ha abụọ nọ n'otu oge.Epoxidation nhọrọ nke Au malitere cyclooctenyl peroxy na oxy radicals bụ ndị na-eje ozi dị ka ndị na-emekọrịta ihe iji malite ethylbenzene oxidation.Usoro a jikọtara ọnụ gbatịrị mmetụta catalytic nke Au.A kwadoro usoro mmeghachi omume site na mmeghachi omume kinetics na nyocha ọnyà.NCCS na-enyere mmeghachi omume yiri ya aka ịga n'ihu na-enweghị mgbochi nke mmekọrịta stoichiometric, na-enye ogo nnwere onwe ọhụrụ na usoro mmepụta hydrocarbon co-oxidation.

Na omenala, ihe na-eme ka onye na-eme ihe na-emekọ ihe ozugbo na ndị na-emeghachi omume (mmeghachi omume A) iji mee ka nhazi nke njikọ nke mmeghachi omume ahụ kwadoro.Dịka ọmụmaatụ, na cobalt-catalyzed oxidation nke alkylaromatics (1) ma ọ bụ Au-catalyzed epioxidation nke cyclooctene (2), ihe na-eme ka ọ dị mfe abstraction nke atom hydrogen sitere na hydrocarbon iji malite mmeghachi omume.Na mmeghachi omume radical free, onye na-akpali akpali na-ekere òkè na nkwụsị nke njikọ na-adịghị ike n'ime ndị na-ebido agbakwunyere ụma ma ọ bụ dị ugbu a dị ka adịghị ọcha na-adịghị mma na ngwakọta mmeghachi omume (1, 3, 4).Ụfọdụ nzọụkwụ na mmeghachi omume catalytic tandem nwere ike ọ gaghị achọ kọntaktị mkpụrụ okwu ozugbo mgbe agbanwere mkpụrụ osisi sitere na ngwaahịa emepụtara n'ụzọ na-akpali akpali na usoro ndị bu ụzọ (5-8).Agbanyeghị, mmeghachi omume ndị a na-amachibido site na mmekọrịta stoichiometric n'etiti nzọụkwụ.Dịka ọmụmaatụ, na Mukaiyama (ep) oxidation nke alkene, onye na-eme ka onye na-eme ihe na-agbanwe ihe reductant ịchụàjà na mmeghachi omume A, dị ka isobutyraldehyde, na nhazi stoichiometric concomitant nke epoxide (reaction B) (9, 10).Ọ bụ ezie na ọ ga-ekwe omume n'ụkpụrụ, anyị amaghị ihe atụ nke ọrụ nke onye na-emepụta ihe bụ ịmepụta ihe etiti S na mmeghachi omume A, ebe S na-eje ozi dị ka onye na-eme ihe na-ebute ma ọ bụ kpalie mmeghachi omume B ọzọ kama isonye dị ka stoichiometric reagent. , ebe onye na-eme ihe na-adịghị mma maka mmeghachi omume B (Fig 1).N'ime atụmatụ dị otú ahụ, mmetụta nke ihe na-eme ka ihe na-eme ka a gbasaa karịa mmeghachi omume A na-emetụtakwa mmeghachi omume B ma na-enweghị kọntaktị kpọmkwem na ndị na-emeghachi ya.Anyị na-akpọ atụmatụ a dị ka sistemụ catalytic na-abụghị kọntaktị (NCCS).Na NCCS, oke mmeghachi omume nke mmeghachi omume A na B ejighị mmekọrịta stoichiometric ọ bụla n'etiti ha.Nke a dị iche na mmeghachi omume tandem.Na ụlọ ọrụ, mmekọrịta stoichiometric dị otú ahụ na-etinyekarị ihe mgbochi akụ na ụba na usoro mmepụta kemịkal.Ihe atụ a ma ama bụ mmepụta stoichiometric nke phenol na acetone site na oxidation nke benzene site na cumene hydroperoxide n'etiti usoro cumene (11).

Ihe na-akpali akpali (Cat) na-eme ka mmeghachi omume A (AR ➔ S ➔AP) nke etiti S dị irè n'ịmalite ma ọ bụ na-eme ka mmeghachi omume B (BR ➔ BP), ọ bụ ezie na mmeghachi omume B adịghị eme ka onye na-eme ihe.

Anyị chọtara NCCS dị otú ahụ mgbe anyị na-enyocha njirimara catalytic nke solubilized Aun clusters (ebe n bụ nke kariri isii ruo asatọ) maka oxidation nke ethylbenzene (EB).Anyị egosila na ndị a solubilized Aun catalyzed nmalite nke nhọrọ epoxidation nke cyclooctene (cC8═) na O2 na ~ 80% selectivity (2).Emebere ụyọkọ ndị a na ọnọdụ n'oge Au/SiO2-catalyzed cC8═epoxidation, ma ha jigidere ike ha ịmepụta radical initiator cycloocctene hydroperoxy radical (cC8═OO·) n'oge mmeghachi omume ahụ.Enwere ike ịnakọta ụyọkọ Aun solubilized na ngwakọta mmeghachi omume mgbe ewepụsịrị Au/SiO2, na nkezi nha ha kpebiri site na iji microscopy eletrọn gbaziri agbaziri na fluorescence spectroscopy (2).Na mgbakwunye na ụyọkọ Aun, ngwakọta ndị a nwekwara cyclooctene hydroperoxide (cC8═OOH) na ngwaahịa oxidation cyclooctene epoxide, cyclooctenol, na cyclooctenone.cC8═OOH bụ ụdị hydrogenated kwụsiri ike nke cC8═OO· ma dị ugbu a na mkpokọta 0.2 ruo 0.5 M ka ngbanwe 40 ruo 100% cC8═.A na-akpọ ngwakọta a dị ka Au + cC8═OOH-x, ebe x bụ ntugharị pasent cC8═.Ọ bụ ezie na n'ọ̀tụ̀tụ̀ dị nnọọ nwayọọ yana ogologo oge (> 5 awa) ntinye oge, cC8═ epoxidation nwekwara ike ime site na auto-oxidation na-enweghị ụyọkọ Aun.Ngwakọta ndị sitere na auto-oxidation na-enweghị Au ka a na-akpọ cC8═OOH-x.Na NCCS, Aun solubilized ga-abụ ihe na-akpali akpali, epioxidation nke cC8═ ga-abụ mmeghachi omume A, na cC8═OO ga-abụ S.

The auto-oxidation nke EB adịghị eme ngwa ngwa.Na 145 Celsius C, naanị mmeghachi omume 9% mere maka EB dị mma n'okpuru 2.76 MPa O2 (12).N'okpuru ọnọdụ anyị dị nro nke 100 Celsius C yana na-agbapụta O2 na 0.1 MPa, ọ nweghị mmeghachi omume EB dị mma nke a na-achọpụta ma ọ dịkarịa ala awa 20.Achọrọ mgbakwunye nke onye mmalite radical efu ka mmeghachi omume a wee gaa n'ihu.Mmalite na 2,2′-azobisisobutyronitrile (AIBN), a ukwuu reactive thermal radical initiator, rụpụtara na auto-oxidation nke EB na nkezi yinye ogologo ~ 3 (fig. S2A).A hụrụ yinye dị mkpụmkpụ (~1) site na iji tert-butyl hydroperoxide nke na-adịghị arụ ọrụ (fig. S2B), na enwere obere mmeghachi omume a na-achọpụta site na iji cumene hydroperoxide kacha nta.Ya mere, auto-oxidation nke EB nwere mmetụta dị nta na nsonaazụ mmeghachi omume kọrọ n'okpuru.

A na-enweta EB hydroperoxide na EB hydroperoxide, acetophenone na phenylethanol site n'ịgbakwụnye Au + cC8═OOH-50 nwere ngwakọta nke Aun, cC8═OOH, na cC8═ enweghị mmeghachi omume (Fig 2, curve 1).Dị ka e gosipụtara site na nnwale ndị a, ihe atọ ndị a rụrụ ọrụ bụ isi na EB oxidation, na ha kwekọrọ na catalyst, S, na AR na usoro NCCS nke e gosipụtara na Fig. 1.

(i) 7 ml nke EB + 3 ml nke Au + cC8═OOH-50;(ii) 7 ml nke EB + 3 ml nke Au + cC8═OOH-50 + 1.2 mmol PPh3;(iii) 7 ml nke EB + 3 ml nke Au + cC8═OOH-99 + 0.6 mmol PPh3;(iv) 7 ml nke EB + 3 ml nke cC8═OOH-50;(v) 7 ml nke EB + 3 ml nke cC8═OOH-50 + 1.5 mmol PPh3.Ọnụ ọgụgụ nke PPh3 agbakwunyere ka atọrọ ka nha nke titrated hydroperoxide (okpomọkụ mmeghachi omume, 100°C).

N'okpuru ọnọdụ anyị, ọ nweghị ikuku EB oxidation a na-ahụ anya mere na ngwakọta nke cC8═ na EB (ya bụ, na-enweghị Cat ma ọ bụ S).Triphenylphosphine (PPh3) na-arụ ọrụ nke ọma n'iwepụ hydroperoxides.A Au + cC8═OOH-99 ngwọta, nke cC8═OOH mechiri site na mgbakwunye PPH3, nwere Aun na obere cC8═ emeghị eme, emeghị ka ọ malite mmeghachi omume EB ọbụlagodi mgbe awa 2 gachara (Fig 2, curve 3), na-egosi na Aun naanị ya adịghị arụ ọrụ.Nsonaazụ a gosikwara na ngwaahịa ndị ọzọ nke cC8═ oxidation, dị ka cyclooctene epoxide, cyclooctene alcohol, ma ọ bụ ketone, enweghị ike ibido EB oxidation.N'adịghị ka nnwale a dị n'elu, mwepụ nke cC8═OOH nwere PPh3 sitere na Au + cC8═OOH-50, hapụ Aun na cC8═ enweghị mmeghachi omume, egbochighị ntụgharị EB (tụlee akụkụ 1 na 2, Fig. 2).

Usoro atọ a nke data tụrụ aro imekọrịta n'etiti Aun na cC8 emeghị emezigharị na mmalite nke EB oxidation.Anyị chere na Aun kpalitere oxidation nke cC8═ iji mepụta cC8═OOH, bụ onye malitere mmeghachi omume EB.Enwere ike ịnwale nke a site n'ịtụle arụmọrụ nke ibido EB oxidation na ngwakọta nke cC8═OOH na cC8═ mana enweghị Aun tupu na mgbe mwepụ nke cC8═OOH na PPh3.Iji ṅomie ọnọdụ nke nnwale ndị mbụ, anyị jiri ngwọta cC8═OOH-50 maka ngwakọta nke cC8═OOH na cC8═ ka ewee mepụtaghachi mmetụta ọ bụla nke cC8═ epoxidation ngwaahịa.Nsonaazụ gosiri na n'ihu cC8═OOH-50, EB meghachiri omume nke ọma (Fig. 2, curve 4).Agbanyeghị, ọ bụrụ na PPh3 wepụrụ cC8═OOH, ọ nweghị mmeghachi omume maka elekere mbụ yana ọrụ emechiri emechi (curve 5).Data ndị a kwadoro ihe nlereanya na ọrụ catalytic nke Aun bụ ka ọ na-emepụta cC8═OOH site na cC8═ oxidation, na cC8═OOH malitere mmeghachi omume EB.Ekwupụtakwara ọrụ catalytic nke Aun site n'ịhụ na ọnụego mbụ nke EB oxidation na enweghị cC8═OOH mụbara site na mmụba Aun (fig. S3).

E gosipụtara ọrụ pụrụ iche nke Aun na NCCS a site n'inyocha Co dị ka ihe ọzọ na-akpali akpali, nke a họọrọ n'ihi na cobalt acetate na cobalt cycloalkanecarboxylate (13) bụ mmepụta ihe mmepụta ihe maka ntụgharị nke EB na acetophenone na molecular O2, na-arụ ọrụ n'okpuru ọnọdụ siri ike ma na-achọ ọnụnọ nke acid na bromide ion.A na-ejikwa ogige co maka nhọrọ ikuku EB oxidation n'ihu organocatalyst N-hydroxyphthalimide (NHPI) ma ọ bụ reductant ịchụ àjà (14, 15).Otú ọ dị, n'okpuru ọnọdụ mmeghachi omume anyị, ọnụnọ nke Co/ZSM-5 emeghị ka ọ bụla oxidation nke EB, cC8═, ma ọ bụ ngwakọta ha ma ọ dịkarịa ala 6 awa.Ya bụ, Co naanị enweghị ike ịmalite mmeghachi omume oxidation.Agbanyeghị, n'ihu ma Aun na cC8═, ọ kwadokwara mmeghachi omume oxidation.Dabere na ọnọdụ ahụ, cC8═ ma ọ bụ EB meghachiri ugboro atọ ruo ise ngwa ngwa mgbe Co/ZSM-5 nọ, na nkwalite ahụ mụbara na ọnụọgụ Co/ZSM-5 (tebụ S2, nnwale 6 ruo 8).Nkesa ngwaahịa EB oxidation gbanwekwara ntakịrị na ọnụnọ Co/ZSM-5.Ịba ụba nke Co/ZSM-5 mụbara acetophenone na-amịpụta na, ruo n'ókè dị nta, phenylethanol na-amịpụta na-efu EB hydroperoxide (tebụ S3, nnwale 6 ruo 8), kwekọrọ n'eziokwu ahụ bụ na Co catalyzed decomposition of EB hydroperoxide ka. acetophenone na phenylethanol na oxidation nke ikpeazụ na acetophenone.Maka mkpa, anyị tinyere Co/ZSM-5 na ngwakọta mmeghachi omume anyị iji belata oge mmeghachi omume.

Ihe dị iche n'etiti NCCS na usoro mmeghachi omume tandem bụ na na mbụ, ọ dịghị mmekọrịta stoichiometric n'etiti mmeghachi omume A na B (Fig 1).Iji kwado na mmeghachi omume anyị mere site na NCCS, anyị nwalere mmetụta nke ịgbanwe nha cC8═ na EB site na nyochaa ọnụego mmeghachi omume nke onye ọ bụla.Ọgụgụ 3 na-egosi nsonaazụ nke ịgbanwe ntinye uche cC8═ mbụ mgbe ị na-edobe itinye uche EB mbụ na ọnọdụ mmeghachi omume ndị ọzọ mgbe niile.Ihe omuma a gosiputara na enweghi mmekorita nke stoichiometric n'etiti onu ogugu nke ndi mmadu abuo meghachiri omume, na-akwado na usoro mmeghachi omume di iche na usoro mmeghachi omume tandem omenala.Nnwale ihe atụ nke mbụ EB dị iche iche ka a na-edozi mkpokọta ndị ọzọ rutere n'otu nkwubi okwu ahụ.Site na data ndị a, agbakọrọ ọnụego mmeghachi omume mbụ (Table 1 na table S2, nnwale 4 na 5) wee gosi ịdị iche iche maka cC8═ na EB.Enweghị mgbanwe mgbanwe na ọnụego mmeghachi omume n'etiti mmeghachi omume abụọ ahụ nke na mgbe otu mmeghachi omume na-aga ngwa ngwa, nke ọzọ ga-eji nwayọọ nwayọọ.Ọnụego mmeghachi omume abụọ ahụ nwere ike ịbawanye n'otu oge, dịka nnwale 4 na 5 gosipụtara na tebụl S2.A ga-atụ anya nkwụsị ahịa ma ọ bụrụ na EB na cC8═ mpi maka otu saịtị mmeghachi omume catalytic ma ọ bụ etiti.Nkwubi okwu a kwekọrọ n'eziokwu na mmeghachi omume n'otu oge nke EB na cC8 enweghị mmetụta ọ bụla ma ọ bụ dị ntakịrị na nkesa ngwaahịa ha n'otu n'otu, dị ka egosiri na Tebụl 1 na tebụl S3.

Nleta izizi cC8═ bụ 0.34 M (A), 1.05 M (B), na 1.75 M (C).Ejiri Decane mejupụta ọdịiche dị na olu cC8═ ejiri.Ọnọdụ ndị ọzọ: 32 mg nke Co/ZSM5, 100°C.

Ihe data ndị a kwekọrọ na atụmatụ nhazi nke egosiri na Fig. 4, bụ nke a na-emesi usoro dị mkpa maka NCCS pụta ìhè na ndị isi egwuregwu na-eme ka ọ pụta ìhè (atụmatụ zuru oke na fig. S8).N'ime usoro a, ụyọkọ Aun na-ebute cC8═ epioxidation okirikiri site na ịmepụta cyclooctenyl radicals (I) na cyclooctenyl peroxy radicals (II).Ndị radicals abụọ a wee sonye na cC8═ epioxidation okirikiri, dị ka e guzobere na mbụ (2, 16).Mgbe EB dị, II na-aghọ molekul intermediary na shuttles n'etiti cC8═ epioxidation okirikiri na EB oxidation okirikiri.Na EB okirikiri, II reacts na EB na-etolite a phenylethyl radical, nke ozugbo na-etolite a phenylethyl peroxy radical (III) site mmeghachi omume na O2, dị ka carbon-centered radical reactions na O2 mara na-nnọọ facile (1).Ihe abstraction hydrogen na-esote nke III na-etolite phenylethyl hydroperoxide na n'ikpeazụ acetophenone na phenylethanol.III nwekwara ike meghachi omume ngwa ngwa na cC8═, nke na-aghọ ụzọ iji mejupụta II nke usoro EB oxidation na-eri.Ya mere, mmeghachi omume EB oxidation anaghị eso ya na nkwụsị stoichiometric nke cC8═ epioxidation mmeghachi omume, ọ dịghịkwa "ịzụ ahịa" na ọnụego mmeghachi omume nke EB na cC8═ dị ka a ga-atụ anya ma ọ bụrụ na ha gbara ọsọ maka otu reagent. ma ọ bụ saịtị na-arụ ọrụ catalytic.N'ihi na II na-ekere òkè na ntinye mmalite na ma EB na cC8═ cycles oxidation mana ọ bụghị ozugbo na usoro nhazi ngwaahịa, njikota mmeghachi omume abụọ ahụ anaghị emetụta nkesa ngwaahịa.

Cyclooctene peroxy radical (II) bụ onye isi etiti na-ebute EB oxidation.Enwere ike ịmaliteghachi II site na mmeghachi omume nke EB peroxy radical (III) na cC8═.N'elu aka ekpe, ụyọkọ Aun na-amalite okirikiri cC8═ epioxidation (okirikiri n'aka ekpe).The okirikiri na nri na-egosi nzọụkwụ maka EB ọxịdashọn.Naanị nzọụkwụ ndị dị mkpa maka NCCS ka egosiri.

Iji nyochaa nguzobe nke etiti radical transient dị ka atụpụtara na Fig 4, anyị gbakwunyere ọnyà 5,5-dimethyl-1-pyrroline N-oxide (DMPO) na ngwakọta mmeghachi omume iji mepụta nitroxide radical spin adducts na radicals efu dị maka nchọpụta na X-band electron paramagnetic resonance (EPR) spectroscopy.Dị ka njikwa, ọ dịghị radicals tọrọ atọ site DMPO na ngwọta nke acetone na decane na-enweghị C8═ ma ọ bụ EB (fig. S4-3).Mgbe agbakwunyere DMPO na ngwakọta mmeghachi omume nwere cC8═OOH na cC8═ (fig. S4-1), egosipụtara EPR ụdịdị dị ka nchikota nke ụdị paramagnetic dị iche iche (A na ọnụ ọgụgụ ahụ, ~ 86% nke ngụkọta. ike ịme anwansị) na obere ụdị abụọ (B na C, ~ 5 na ~ 9% nke ike ịme anwansị zuru oke, n'otu n'otu), na-enye ihe akaebe doro anya nke nhazi radical n'oge mmeghachi omume.N'ịtụle ụkpụrụ njikọ njikọ hyperfine na nke DMPO adducts mara (tebụ S1), e kenyere ụdị C na DMPO/ROO• adduct, nke doro anya na cyclooctene 3-peroxy radical (II) gosipụtara dị ka onye na-emekọrịta ihe n'etiti ha abụọ. mmeghachi omume (Fig 4).A na-ekenye ụdị A na B na ntinye DMPO/RO• abụọ dịtụ iche, ebe R na-ezo aka na ikuku hydrocarbon.Ha nwere ike ịbụ otu n'ime ụdị RO• akọwara na Fig. 4 ma ọ bụ alkoxy radicals emepụtara site na DMPO/ROO• adduct decay [DMPO/ROO• adducts bụ nke a maara na ọ bụ ihe na-adịghị eguzosi ike n'ihe na decompose na alkoxy radical adduct (17, 18)] ma ọ bụ ngwakọta nke abụọ.Mgbe EB tinyekwara na ngwakọta mmeghachi omume, e gosipụtara ụdịdị EPR nke ọma na ọtụtụ ụdị A′, nke yiri ụdị A (DMPO/RO•), yana ụdị obere abụọ B na C nwere obere onyinye ndị yiri ya. (fig. S4-2 na tebụl S1).N'ihi na ntinye nke EB na-atụ anya na ọ ga-eme ka e guzobe phenylethyl peroxy radicals (III), ụdị A′ nwere ike ịbụ ngwakọta nke RO • emepụtara na mmeghachi omume yana ihe ọ bụla phenylethyl peroxy adduct, nke mechara ree phenylethyl oxy DMPO.

Iji EB-d10 dị ka onye na-emeghachi omume na nleba anya deuterium labeling na cC8═ ngwaahịa nwere ike ịchọpụta ma enwere mmeghachi omume EB nwere cC8═ carbon radicals dabere.Nsonaazụ nke nnwale dị otú ahụ gosiri na ọ dịghị deuterium incorporation na cyclooctene epoxide (fig. S5 na S6).Phenylethanol jigidere deuterium niile na EB reactant, na ụfọdụ ndị deuterons nọ na methyl otu acetophenone agbanweela, nke nwere ike ime na spectrometer uka.Ya mere, enweghi ihe akaebe nke mmeghachi omume n'etiti EB-d10 na cyclooctenyl radical, nke ga-ewebata deuteron n'ime ngwaahịa cC8═.

Agbakwunyere ike nke atụmatụ NCCS iji nyochaa Au + cC8═OOH-100–enyere aka ikuku oxidation nke 4-methylanisole.N'ihi njikọ C ─H siri ike dị na molekul a, a na-eme mmeghachi omume oxy-functionalization na okpomọkụ dị elu.Atụnyere ọnụego mbụ nke ntụgharị 4-methylanisole na 4-anisaldehyde maka mmeghachi omume malitere na Aun yana ma ọ bụ na-enweghị mgbakwunye cC8═ (cC8═OOH wepụrụ ya na PPh3).Yiri EB oxidation, mgbe ngwakọta mmeghachi omume enweghị cC8═ na enweghị cC8═OOH, ọnụ ọgụgụ mbụ oxidation adịchaghị ngwa ngwa (fig. S7).Mgbe agbakwunyere cC8═ na ngwakọta mmeghachi omume, ọ̀tụ̀tụ̀ oxidation mbụ ka agbalitere nke ọma.Ya mere, ụyọkọ Aun nwere ike ịmepụta cC8═OOH site na cC8═ agbakwunyere iji malite oxidation nke 4-methylanisole dị ka a tụrụ anya na NCCS.

N'ikpeazụ, anyị egosipụtala echiche nke NCCS.N'iji oxidation nke cyclooctene na EB n'otu oge yana cyclooctene na 4-methylanisole, NCCS gosipụtara iji mee ka co-oxidation nke hydrocarbons na-enweghị njedebe mmekọrịta stoichiometric nke usoro co-oxidation omenala.Nke a na-enye ogo nnwere onwe na-adịghị adị na mbụ na omume ụlọ ọrụ dị otú ahụ nke na usoro akụ na ụba usoro agaghịzi ejikọta site na mkpa maka ahịa dị mma maka ngwaahịa ndị na-emepụta na ego stoichiometric.

Isi mmalite na ịdị ọcha nke kemịkal eji eme ihe bụ ndị a: HAuCl4 • 3H2O (≥99.9% trace metals base, Sigma-Aldrich), fumed silica (CAB-O-SIL90, Cabot Corporation), ethylenediamine (≥99% ReagentPlus, Sigma-Aldrich) , ethanol (200 ọkwa, Decon Labs), cobalt (II) nitrate 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) . (reagent grade, 90%, Sigma-Aldrich), sodium sulfate (Food Chemicals Codex/United States Pharmacopeia-grade, Fisher Chemical), tetrahydrofuran (> 99%, Sigma-Aldrich), tert-butyl hydroperoxide (~ 5.5 M na decane). , Sigma-Aldrich), PPh3 (> 98.5%, Sigma-Aldrich), d-chloroform (99.8 atomic% D, Sigma-Aldrich), HCl (38% w / w, Fisher Chemical), HNO3 (68 ka 70% w) / w, Fisher Chemical), EM Quant peroxide mpempe ule, na nzacha sirinji (polyvinylidene difluoride membrane, 0.25 mm/0.2 μm, Acrodisc).

Au/SiO2.A na-eji Au(en) 2Cl3 precursor kwadoro ihe nanoparticle ọla edo na-akwado silica dịka usoro Zhu et al mepụtara.(19) ma gbanwee site na Qian et al.(2).Iji mee ka ọ dịkwuo nkọwa, a kwadebere ngwọta Au (III) chloride trihydrate site na igbari 0.5 g nke HAuCl4 • 3H2O na ngwakọta nwere 10 ml ethanol na 2 ml mmiri.Mgbe emechara ihe ngwọta otu, 0.23 ml nke ethylenediamine (en = ethylenediamine) agbakwunyere na ngwọta dropwise iji mepụta Au (III) ethylenediamine chloride [Au (en) 2Cl3] site na mgbanwe ligand.A nakọtara Au(en) 2Cl3 nke emebere site na nzacha wee were 300 ml nke ethanol sachaa ya.Iji tinye Au n'elu nkwado silica, 4.2 mM Au(en)2Cl3 edozira mmiri mmiri site na igbari 46.3 mg nke Au(en) 2Cl3 n'ime 26 ml nke mmiri distilled deionized (DDI).A na-edobe ihe ngwọta dị ka 40 Celsius C na mmanụ bat.Mgbe ahụ, a na-agbakwunye 1 g nke silica fumed na ngwọta a na-ekpo ọkụ mgbe ọ na-akpali.Ozugbo ihe nkwado silica niile na-emikpu n'ime ngwọta ahụ, a na-ewepụ ihe ngwakọta ahụ na mmanụ bat ma mee ka ọ dị jụụ na okpomọkụ.Site n'ịgbanwe pH nke ngwakọta na 9 na ntinye ntinye nke 0.75 M na ngwọta mmiri, a na-enweta mgbasa ozi ka mma nke ụlọ ọla edo cationic na elu ebubo na-adịghị mma.Mgbe ị na-emegharị maka awa 2 na ụlọ okpomọkụ, a na-edozi ngwakọta ahụ ma saa ya na 500 ml nke mmiri DDI.Iji wepụ ihe ndị a na-achọghị (Cl, en, adịghị ọcha ndị ọzọ), a na-atụgharị achicha nzacha na 200 ml nke mmiri DDI na 40 ° C.N'ikpeazụ, a na-anakọta Au/SiO2 dị ka emebere site na nzacha wee jiri 500 ml nke mmiri DDI ọzọ saa ya ma kpoo na ikuku n'abali.Calcination nke ihe nanoparticles ọla edo na-akwado silica bụ nke emere n'ime tube nke dị n'okpuru mmiri O2/O3 (~ 300 ml/min) nwere ọnụ ọgụgụ ramping nke 0.12°C/min ruo 150°C.A na-echekwa ihe ọkụkụ n'ọchịchịrị na 5 Celsius.Ibu ọla edo, dị ka agbakọrọ site na inductively jikọtara plasma optical emission spectrometry, bụ 1.2 arọ % (wt %), na nkezi urughuru ọla edo tụrụ site na nyocha eletrọnịkị eletrọnịkị (STEM) gbara gburugburu 2 nm.

Njikọ/ZSM-5.Nano H-ZSM-5 bụ calcined na a U-tube n'okpuru O2 / O3 eruba (~ 300 ml / min) na a ramping ọnụego nke 2°C/min ruo 200°C ma jide na 200°C maka 1 hour iji wepu. ndebiri fọdụrụnụ.A kwadoro Co/ZSM-5 site na mmiri mmalite.Dịka ọmụmaatụ, a kwadebere 5 wt % loading Co/ZSM-5 site n'ịgbakwunye 0.72 M cobalt (II) nitrate solution [250 mg nke cobalt (II) nitrate hexahydrate na 1.2 ml nke mmiri DDI] na 1 g nke nano H- ZSM-5 ka ọ na-atụgharị nke ọma na beaker.A na-akpọnwụ slurry n'okpuru oriọna, ma kpụrụ ntụ ntụ pink edo edo.A na-ebunye ntụ ntụ a kpụrụ akpụ n'ime tube calcination kwụ ọtọ wee sachaa n'okpuru mmiri argon (100 ml / min) maka elekere 1 iji belata iru mmiri.A na-emezi ihe na-eme ka a kwadebere dị ka nke a kwadebere n'okpuru ikuku oxygen (60 ml / min) na ọnụ ọgụgụ ramping nke 10 ° C/min ruo 450 ° (ejidere na 250 ° C, 350 ° C, na 450 ° C maka elekere 1 nke ọ bụla) .Co/ZSM-5 enwetara nwere ntinye cobalt nke 5 wt%.A kwadokwara ngwunye abụọ ọzọ, 3 na 7 wt.E ji ihe mkpali atọ ahụ pụta bụ Mbelata okpomọkụ H2, mgbawa x-ray, x-ray photoelectron spectroscopy, na ultraviolet-visible spectroscopy.

Au-nwere filtrate.Ihe nzacha nke Au-nwere (Au + cC8═OOH-x) dị n'ọnọdụ ewepụtara site na Au/SiO2-catalyzed cC8═ epioxidation mmeghachi omume dịka usoro nke Qian et al mepụtara.(2) Tupu mmeghachi omume, cC8═ dị ọcha iji wepụ ihe nkwụsi ike agbakwunyere.N'ozuzu, 50 ml nke 3M potassium hydroxide (KOH) ngwọta agbakwunyere na 50 ml nke cC8═ n'ime flask.Mgbe ngwakọta zuru oke na mkpali siri ike, a na-anakọta oyi akwa organic site na nkewa.Emeghachiri usoro a na 50 ml ọzọ nke 3 M KOH na abụọ ọzọ 50 ml nke DDI mmiri.Ejiri sodium sulfate kpochaa cC8═ n'abali.Iji wepụ ihe nkwụnye ahụ kpamkpam, cC8═ a mịrị amị na-agbanye n'ime bat mmanụ na gburugburu 180 Celsius, ma chịkọta akụkụ nke pụtara na 145 ° C.Agwakọtara cC8═ (10 ml) na decane (1 ml) dị ọcha n'ime reactor nwere 80 mg nke ihe ntụzịaka Au/SiO2 akpọtụrụla.Emere mmeghachi omume cC8═ epioxidation n'okpuru ikuku oxygen (30 ml / min) na 100 Celsius, GC na-enyocha ntụgharị ahụ.Ozugbo ntụgharị a chọrọ, a na-anakọta ngwakọta mmeghachi omume na-ekpochapụ ihe siri ike site na nzacha ọkụ site na iji nzacha sirinji.Ihe nleba anya Au nke solubilized nke ekpebisiri ike site na inductively jikọtara plasma mass spectrometry bụ ihe dịka 80 ng/ml, na nha ụyọkọ Au ka ekpebisiri ike site na fluorescence spectroscopy na aberration-doziri nnyefe eletrọn microscopy sitere na atom ruo ~0.7 nm.A kwadebere cC8═OOH-x n'otu aka ahụ na-ejighi Au/SiO2 ihe mkpata.Ma Au + cC8═OOH-x na cC8═OOH-x nwere ngwaahịa cC8═ oxidation, nke gụnyere cyclooctene oxide, cycloocten 3-hydroperoxide, 2-cycloocten-1-ol, 2-cycloocten-1-otu, na ọnụọgụ ọnụọgụ. nke 1,2-cyclooctanediol.

Usoro izugbe.A na-eme mmeghachi omume EB oxidation n'ọchịchịrị n'ime igwe ọkụ cylindrical nwere olu atọ nwere ezigbo frit glass disperser tube (Chemglass Life Sciences) na condenser nke edobere na -10°C.Na mmeghachi omume a na-ahụkarị, 7 ml nke EB, 1 ml nke decane, na 3 ml nke filtrate (Au + cC8═OOH-x ma ọ bụ cC8═OOH-x) ka etinyere n'ime reactor yana ihe ndọta nke Teflon nwere mkpuchi.Ọ bụrụ na ejiri ya, 32 mg nke 5% Co/ZSM-5, ọ gwụla ma akọwapụtara ya ọzọ, agbakwunyere.Mgbe emechara nhazi mmeghachi omume ahụ, a na-eme ka ngwakọta mmeghachi omume guzosie ike n'okpuru N2 na-agba ọsọ maka 20 min na mmanụ a na-ekpo ọkụ.Ozugbo okpomọkụ nke condenser na mmanụ bat kwadoro, a na-enyefe O2 mgbe niile na 30 ml / min.A na-ewere ngwakọta mmeghachi omume (0.1 ml) n'oge dị iche iche maka nyocha (a na-eji nzacha sirinji mee ihe mgbe ihe ndị siri ike na-etinye aka), gbazere na 0.7 ml nke d-chloroform, ma nyochaa site na 1H nuclear magnet resonance (NMR).

njirimara ngwaahịa na nha.Eji tetrahydrofuran gbazere Aliquots nke ngwakọta mmeghachi omume wee nyochaa site na chromatography-mass spectrometry gas (GC-MS; Agilent GC-7890A, MS-5975).Maka mmeghachi omume EB, acetophenone na 1-phenylethanol bụ ngwaahịa kachasị.1H-NMR na 13C-NMR (400 MHz Agilent DD2-MR400 sistemu) ka ejiri wee kwadokwuo njirimara ngwaahịa.1-Phenylethyl hydroperoxide, nke GC-MS na-achọpụtaghị n'ihi enweghị ike ọkụ ya, NMR chọpụtara na ọ bụ ngwaahịa ọzọ na-achịkwa.Ejiri 1H-NMR tụọ ngwaahịa atọ niile site na iji decane dị ka ọkọlọtọ ime (fig. S1).A na-ekpebi ọnwụ evaporative iche iche ma jiri ya dozie mkpokọta ngwaahịa.Mgbe emezichara maka mfu nke evaporative, ọnweghị ahaghị nhata carbon a hụrụ maka mmeghachi omume EB.Maka mmeghachi omume cycloocten, cyclooctane oxide, cyclooctane-1,2-diol, 2-cycloocten-1-ol, na 2-cycloocten-1-otu bụ GC.Cyclooctene 3-hydroperoxide esighi ike ma mebie ya na kọlụm GC ya mere achọpụtaghị ya.Enwere ihe dị ka 10% mfu carbon na ngbanwe zuru oke ọbụlagodi mgbe akwụsịrị ụgwọ maka mfu evaporative, nke enwere ike ịkọwa site n'ịmepụta obere ngwaahịa na-enweghị atụ nke ukwuu.

Ngbanwe na ngụkọ nhọrọ.Oke mpaghara GC ma ọ bụ NMR nke molecule nke mmasị na decane ọkọlọtọ dị n'ime ka ejiri gbakọọ ntụgharị na nhọrọ.Ọ bụ ezie na ejiri condenser jụrụ oyi, ọ ka dị mkpa iji kwụọ ụgwọ maka mfu evaporative n'ihi nnukwu mmeghachi omume okpomọkụ na ogologo oge mmeghachi omume.Enwetara akụkụ mgbazi nke evaporative maka ma EB na cC8═ n'okpuru nitrogen na-eru eru ma mee ka ọ dị nha nke EB/decane ma ọ bụ cC8═/decane.N'ihi na EB na cC8 ═ nwere isi ihe na-esi esi esi, ihe mmezi emezigharị enwetara bụ 0.0044 (nhazi nke ebelatara kwa elekere).

Nkọwa nke hydroperoxide.Ejiri ụzọ abụọ titration gbakọọ mkpokọta hydroperoxide:

1) Triphenylphosphine (PPh3) titration.PPh3 (0.1 M na EB) ka ejiri mee titrate ihe nlele hydroperoxide na-amaghị, na njedebe njedebe ka ejiri eriri ule EM Quant peroxide mara.Ejiri 31P-NMR gosi na mkpochapụ nke ụdị hydroperoxide zuru oke.

2) Iodometric titration.A na-ejikọta ihe nlele (0.2 ml) na 1 ml nke CHCl3 / acetic acid (v / v = 1: 2) na 6 ml nke ngwọta 1 M KI.A kpalitere ngwakọta ahụ n'ọchịchịrị maka awa 2 wee tinye ya na 0.005 M Na2S2O3 n'ihu ntụ ntụ ntụ ọka starch ole na ole.E ruru njedebe njedebe mgbe ngwakọta ghọrọ enweghị agba.

Ụzọ abụọ a na-agbanwe agbanwe n'ime;Otú ọ dị, nsonaazụ ha dị iche site na 5 ruo 10%.N'ihi na Au + cC8═OOH-x na cC8═OOH-x ejiri rụọ ọrụ a bụ nke sitere na cC8═OOH malitere oxidation, ntinye hydroperoxide dị iche site na ogbe ruo ogbe mana ọ na-anọkarị n'etiti 0.2 ruo 0.5 M maka nkwadebe ọhụrụ. cC8═OOH-40 ruo cC8═OOH-100 sample.Ọnụnọ nke hydroperoxide ji nwayọọ nwayọọ na-agbada site n'oge nchekwa.

Nnwale ọnyà nke EPR.A na-agbakwunye DMPO (23 μl) na 1 ml nke ihe nlele ahụ iji ruo nchịkọta DMPO nke 0.2 M, na 20 mg nke Co / ZSM-5 agbakwunyere na ngwakọta ihe atụ na tube ule.A na-agwakọta ngwakọta ahụ maka 1 min iji kwụsịtụ ihe na-akpata, nke a na-esote okpomọkụ na 60 ° C maka ~ 10 min.A na-ebufe ngwakọta nke ngwakọta ahụ n'ime tube capillary tubing borosilicate (1.50 n'ime dayameta × 1.80 n'èzí dayameta, Wale Apparatus), nke a na-emechi ya n'otu njedebe - a na-etinye tube a na Wilmad quartz X-band EPR tube ( Sigma-Aldrich).Emebere ihe nlele ahụ site na imikpu nke tube EPR n'ime mmiri mmiri N2.Ozugbo tupu ị tụọ ihe nkiri EPR, agbazere ihe nlele ahụ.Na-aga n'ihu-wave (CW) X-band EPR nha ka a rụrụ na ọnụ ụlọ okpomọkụ na Varian E-4 spectrometer gbanwere site na iji mkpịsị aka Dewar.

Nnwale akara akara Isotopic.Ejiri Deuterated EB (d10-EB) mee nnwale nke ngwakọta nke 6 ml nke cC8═OOH-45, 5 ml nke d10-EB, 1 ml nke decane, na 60 mg nke Co-ZSM-5 (7%). , na 120°C, na 6 ml nke cC8═OOH-45, 5 ml nke EB-d10, na 1 ml nke dodecane.Iji kwụọ ụgwọ maka mbelata nke mmeghachi omume mmeghachi omume n'ihi mmetụta kinetic isotope, a na-eme co-oxidation na okpomọkụ dị elu nke 120 ° C.A na-ewere ihe nlele tupu na mgbe awa 24 nke mmeghachi omume gasịrị wee nyochaa site na 2H-NMR na GC-MS.

Ihe ngosi 2H-NMR (fig S5, spectrum 2) gosipụtara ọtụtụ ọnụ ọgụgụ ọhụrụ mgbe mmeghachi omume gasịrị, ọ bụghị tupu mmeghachi omume, na δ1.50, δ1.58, δ4.94, δ7.42 na δ7.72, na δ8.04 .N'ihi mbelata J-njikọ mgbe niile na uche nke 2H-NMR, edozibeghị usoro nkewa ahụ.E kenyere ọnụ ọgụgụ kasị elu na δ8.04 na δ7.42 ruo δ7.72 na deuterons nke mgbanaka aromatic nke acetophenone;E kenyere ọnụ ọgụgụ kasị elu na δ1.50 na δ4.94 na methyl na benzylic deuteron nke 1-phenylethanol, n'otu n'otu;na ọnụ ọgụgụ kasị elu na δ1.58 ka e kenyere deuteron na D2O nke e mepụtara site na nbibi hydroperoxide.Achọghị deuteron na ngwaahịa nke cyclooctene epoxidation, na nguzobe nke mmiri deuterated gosipụtara na ndị na-ebugharị radical chain na mmeghachi omume co-oxidation bụ peroxy na alkoxy dabeere.

E gosipụtara ụdịdị GC-MS nke ngwaahịa a na fig.S6.Acetofenone-d8 (m / e 128, deuterated zuru oke, fig. S6A, m/e 127 na 126).Site na usoro mgbawa, mgbanwe HD niile mere na ọnọdụ methyl.Na mgbakwunye, 1-phenylethanol-d9 (m/e 131) (fig. S6B) bụ naanị ngwaahịa deuterated achọpụtara.Achọghị deuterium na cyclooctene oxide (fig. S6C), ngwaahịa kachasị ukwuu sitere na cyclooctene epioxidation.Enwere ike ịmepụta 1-Phenylethanol-d9 site na mmeghachi omume nke phenylethoxy radical na cyclooctene.

Ihe mgbakwunye maka akụkọ a dị na http://advances.sciencemag.org/cgi/content/full/6/5/eaax6637/DC1

Foto S5.2H-NMR tupu (ụdịdị 1, uhie) na mgbe (ụdịdị dị iche iche 2, akwụkwọ ndụ akwụkwọ ndụ) mmeghachi omume co-oxidation nke awa 24.

Foto S7.Ntụle mgbanwe mbụ nke 4-methyl anisole bidoro site na iji Au + cC8═OOH-100, wepụrụ cC8═OOH.

Nke a bụ edemede oghere mepere emepe ekesara n'okpuru usoro ikike nke Creative Commons Attribution-NonCommercial, nke na-enye ohere iji, nkesa, na mmeputakwa n'ụdị ọ bụla, ma ọ bụrụhaala na nsonaazụ ya abụghị maka uru azụmahịa ma ọ bụrụhaala na ọrụ mbụ ahụ dabara nke ọma. kwuru.

IHE: Anyị na-arịọ naanị adreesị ozi-e gị ka onye ị na-atụ aro ibe ya mara na ị chọrọ ka ha hụ ya, na ọ bụghị ozi junk.Anyị anaghị ejide adreesị ozi-e ọ bụla.

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

N'ime sistemu catalytic na-adịghị emekọrịta ihe, ndị na-emekọrịta ihe na-enweta site na Au-catalyzed cyclooctene epioxidation mmetụta ethylbenzene oxidation.

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

N'ime sistemu catalytic na-adịghị emekọrịta ihe, ndị na-emekọrịta ihe na-enweta site na Au-catalyzed cyclooctene epioxidation mmetụta ethylbenzene oxidation.

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