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I-formic acid ngenye yezinto ezithembisako zokugcina isikhathi eside i-hydrogen ewuketshezi. Lapha siveza uchungechunge lweenhlanganisela ezitjha ze-ruthenium clamp ngefomula ejayelekileko [RuHCl(POP)(PPh3)] sisebenzisa ama-ligands we-ksanthos-type tridentate POP atholakala lula namkha akhiwe lula. Sisebenzise iinhlanganisela lezi ukukhipha i-formic acid ukukhiqiza i-CO2 ne-H2 ngaphasi kweemeko ezilula, ezingana-reflux sisebenzisa i-ionic liquid BMIM OAc (1-butyl-3-methylimidazolium acetate) njenge-solvent. Ngokombono wefrikhwensi ephezulu yokubuya, isikhuthazi esisebenzako khulu yi-[RuHCl(xantphos)(PPh3)]Ru-1 eyaziwako eencwadini, enemvamisa ephezulu yokubuya kwe-4525 h-1 ku-90 °C imizuzu eli-10. Izinga lokutjhuguluka kwangemva bekungu-74%, begodu ukutjhuguluka kwaqedwa kungakapheli ama-awa ama-3 (>98%). Ngakelinye ihlangothi, isikhuthazi esisebenza kuhle khulu, i-noveli [RuHCl(iPr-dbfphos)(PPh3)]Ru-2 complex, ikhuthaza ukutjhuguluka okupheleleko ngaphakathi kwe-1 h, okurholela ekutheni kube nezinga lokubuya elipheleleko le-1009 h-1. Ukungezelela, umsebenzi we-catalytic nawo wabonwa emazingeni womtjhiso afika ku-60 °C. Esigabeni segesi, kwabonwa i-CO2 ne-H2 kwaphela; I-CO ayizange itholakale. I-high-resolution mass spectrometry itjengise ubukhona be-N-heterocyclic carbene complexes emhlanganisweni wokusabela.
Isabelo esikhulako semakethe yamandla avuselelekako nokutjhuguluka kwawo kuholele ekufuneni ubuchwepheshe bokugcina amandla wezinga lamabubulo emkhakheni wamandla, womtjhiso, webubulo nezokuthutha1,2. I-hydrogen ithathwa njengenye yezinto ezithwala amandla ezinengi khulu3, begodu i-hydrogen carriers ye-liquid organic (ama-LOHC) sele iqakatheke khulu ekurhubhululeni, inikela ngesithembiso sokugcina i-hydrogen ngendlela elungiswa lula ngaphandle kwemiraro ehlotjaniswa nokugandeleleka nofana ithekhnoloji ye-cryogenic4. ,5,6. Ngebanga lezakhiwo zazo ezibonakalako, inengi leensetjenziswa zokuthutha ezikhona ze-petroli nezinye iinsetjenziswa ezimanzi zingasetjenziselwa ukuthutha i-LOHC7,8. Iimfanelo ze-formic acid (FA) zenza bona ibe yinto ehle yokugcina i-hydrogen enesisindo se-hydrogen esingu-4.4%9,10. Kodwana, iinhlelo ezigadangisiweko zokukhipha i-formic acid ngokuvamileko zitlhoga ukusetjenziswa kwe-volatile organic solvents, amanzi nofana i-formic acid ehlanzekileko,11,12,13,14 okungatlhoga ukusetjenziswa kwamaqhinga wokuhlukanisa umhwamuko we-solvent afana nokuncibilika, okungadosela emirarweni eensetjenzisweni zabathengi. iinsetjenziswa, umthwalo owengeziweko. Umraro lo ungaqedwa ngokusebenzisa iinsombululo ezinomfutho womhwamuko ongatjho litho, njengama-ionic liquids. Ngaphambilini, isiqhema sethu sokusebenza satjengisa bona i-ionic liquid butylmethylimidazolium acetate (BMIM OAc) siyi-solvent efaneleko kilokhu kuphendula ngokusebenzisa i-fixing complex etholakala emabhizinisini i-Ru-PNP Ru-MACHO type 15. Ukwenza isibonelo, sitjengise i-FA dehydrogenation erherhweni lokugeleza okuragela phambili ngokusebenzisa i-BMIM OAc, ukufikelela phezu kwe-TON 18,000,000 ku-95°C. Nanyana amanye amasistimu sele afinyelele i-TON ephezulu, amanengi athembele eentweni ezitjhugulukako (ezifana ne-THF nofana i-DMF) nofana iinthako ezisetjenzisiweko (ezifana nama-base). Ngokuphikisako, umsebenzi wethu usebenzisa amanzi angaguqukiko we-ionic (ama-IL) begodu ngaphandle kokungezelela.
U-Hazari no-Bernskoetter babike ukukhipha i-hydrogenation ye-formic acid (FA) ku-80 °C ngokusebenzisa i-Fe-PNP catalyst ebukhoneni be-dioxane ne-LiBF4, ukufikelela inani elikarisako lokubuya (TON) elingaba yi-1,000,00016. U-Laurenci wasebenzisa i-Ru(II)- complex catalyst TPPPTS erherhweni lokukhipha i-FA eliragela phambili. Indlela le yenza bona i-FA iphume ngokupheleleko ngemikhondo emincani khulu ye-CO etholakala ku-80 °C17. Ukuthuthukisa umkhakha lo, u-Pidko utjengise ukubuyiselwa emuva kwe-FA ngokusebenzisa i-Ru-PNP clamp catalysts ku-DMF/DBU kanye ne-DMF/NHex3, ukufikelela amanani we-TON we-310,000 ukuya ku-706,500 ku-90 °C18. U-Hull, u-Himeda no-Fujita bafunda nge-binuclear Ir complex catalyst lapho i-KHCO3 ne-H2SO4 zahlatshwa khona, kutjhugulula i-CO2 hydrogenation ne-FA dehydrogenation. Iinhlelo zabo zifinyelele ama-TON angaphezu kwama-3,500,000 kanye nama-308,000 ngokulandelana malungana nokukhipha i-hydrogenation ku-30°C, i-CO2/H2 (1:1), i-1 bar pressure kanye nokukhipha i-hydrogenation hlangana kwama-60 ukuya ku-90°C19. U-Sponholz, u-Junge no-Beller bakha i-Mn-PNP complex yokubuyela emuva kwe-CO2 hydrogenation kanye ne-FA dehydrogenation ku-90 °C20.
Lapha sisebenzise indlela ye-IL, kodwana kunokuthi sisebenzise ama-Ru-PNP, sihlole ukusetjenziswa kwama-catalysts we-Ru-POP, ngokwazi kwethu azange atjengiswe ngaphambilini malungana nalokhu.
Ngebanga lokuhlanganiswa kwawo okuhle khulu kwe-metal-ligand (MLC), ama-amino-PNP clamp complexes asekelwe emibonweni ye-Noyori-type enamaqembu we-amino wesibili asebenzisanako 21 (njenge-Ru-MACHO-BH) avamise ukuthandwa khulu kweminye imisebenzi yamamolekhyuli amancani. Iimbonelo ezidumileko zifaka hlangana i-CO22, ukufakwa kwe-hydrogenation kwama-alkenes nama-carbonyls, ukudluliswa kwe-hydrogenation23 kanye nokukhiqizwa kwama-hydrogenation ngaphandle kokwamukela kwama-alkhoholi24. Kubikwe bona i-N-methylation yama-PNP clamp ligands ingamisa ngokupheleleko umsebenzi we-catalyst25, okungachazwa ngokuthi ama-amines asebenza njengemithombo yamaphrothoni, okuyimfuneko eqakathekileko ngesikhathi somjikelezo we-catalytic ngokusebenzisa i-MLC. Kodwana, umukghwa ophikisanako we-formic acid dehydrogenation usanda kubonwa ngu-Beller, lapho i-N-methylated Ru-PNP complexes kwamambala itjengise ukukhipha i-catalytic dehydrogenation engcono ye-formic acid kunabalingani babo abangaka-methylated26. Njengombana i-complex yangaphambilini ingakghoni ukuzibandakanya ku-MLC ngeyunithi ye-amino, lokhu kusikisela khulu bona i-MLC, begodu ngalokho iyunithi ye-amino, ingadlala indima engakaqakatheki kezinye iinguquko (zokukhipha i-hydrogenation) kunangendlela ebekucatjangwa ngayo ngaphambilini.
Nayiqathaniswa nama-clamp we-POP, ama-ruthenium complex wama-POP clamps awakafundwa ngokwaneleko endaweni le. Ama-ligands we-POP bekasolo asetjenziselwa khulukhulu ukukhiqiza i-hydroformylation, lapho asebenza khona njenge-chelating ligands kunokobana kube yi-angle ye-bidentate bite engaba yi-120° yokubopha ama-ligands, ebegade asetjenziselwa ukwenza ngcono ukukhetha kwemikhiqizo eqondileko neyamagatja27,28,29. Solo kwalokho, iinhlanganisela ze-Ru-POP bezingakavami ukusetjenziswa ekuthuthukiseni i-hydrogenation, kodwana iimbonelo zomsebenzi wazo ekudluliseleni i-hydrogenation sele zibikwe ngaphambilini30. Lapha sitjengisa bona i-Ru-POP complex iyi-catalyst ephumelelako yokukhipha i-hydrogenation ye-formic acid, okuqinisekisa ukutholwa kwaka-Beller kobana iyunithi ye-amino ku-classic Ru-PNP amine catalyst ayikaqakatheki kangako kilokhu kuphendula.
Irhubhululo lethu lithoma ngokuhlanganiswa kwama-catalyst amabili ajayelekileko ngefomula ejwayelekileko [RuHCl(POP)(PPh3)] (Umfanekiso 1a). Ukutjhugulula isakhiwo se-steric ne-elekthronikhi, i-dibenzo[b,d]furan yakhethwa ku-4,6-bis(diisopropylphosphino) (Isithombe 1b) etholakala emabhizinisini. isandulela. Hlanganisa i-precursor yensimbi kanye ne-POP clamp ligand ku-THF ngaphasi kweemeko ezinganamanzi nezinganamoya. Ukusabela kwakhambisana nokutjhuguluka kombala okuqakathekileko ukusuka ebubendeni obumnyama ukuya ephuzi begodu kwanikela umkhiqizo ohlanzekileko ngemva kwama-awa ama-4 wokubuyela emuva nofana ama-awa ama-72 wokubuyela emuva ku-40°C. Ngemva kokususa i-THF ngaphakathi kwe-vacuo nokugeza kabili nge-hexane nofana nge-diethyl ether, i-triphenylphosphine yasuswa ukunikela umkhiqizo njengepuyere ephuzi ngesivuno esiphezulu.
Ukuhlanganiswa kwe-Ru-1 ne-Ru-2. a) Indlela yokuhlanganisa izinto eziyinkimbinkimbi. b) Isakhiwo sento ehlanganisiweko.
I-Ru-1 sele yaziwa emitlolweni32, begodu ukuhlathulula okungeziweko kugxile ku-Ru-2. I-1H NMR spectrum ye-Ru-2 iqinisekise ukuhlelwa kwe-cis ye-athomu ye-phosphine ku-ligand ye-hydride pair. Iplothi ye-dt ephezulu (Umfanekiso 2a) itjengisa ama-2JP-H wokuhlanganisa ama-28.6 kanye nama-22.0 Hz, angaphakathi kwebanga elilindelweko lemibiko edlulileko32. Ku-hydrogen decoupled 31P{1H} spectrum (Fig. 2b), i-2JP-P coupling constant engaba ngu-27.6 Hz yabonwa, okuqinisekisa bona zombili i-clamp ligand phosphines kanye ne-PPh3 zi-cis-cis. Ukungezelela, i-ATR-IR itjengisa ibhande lokulula le-ruthenium-hydrogen ku-2054 cm-1. Ukuragela phambili nokucaciswa kwesakhiwo, i-Ru-2 complex yakhiqizwa ngokusabalala komhwamuko emazingeni womtjhiso wegumbi ngekhwalithi eyaneleko yezifundo ze-X-ray (Umfanekiso 3, Ithebula elingezelelweko 1). Ikharistali ehlelweni le-triclinic le-space group P-1 ngeyunithi eyodwa ye-benzene ye-cocrystalline ngeyunithi ngayinye yeseli. Itjengisa i-P-Ru-P occlusal angle ebanzi eyi-153.94°, ebanzi khulu kune-130° occlusal angle ye-bidentate DBFphos34. Ku-2.401 no-2.382 Å, ubude besibopho se-Ru-PPOP bude khulu kunobude besibopho se-Ru ukuya ku-PPh3 esingu-2.232 Å, okungenzeka kube mphumela we-angle ebanzi ye-DBFphos ebangelwa yi-5-ring yayo ephakathi. Ijometri yesikhungo sensimbi yi-octahedral nge-O-Ru-PPh3 engela ye-179.5°. Ukuhlanganiswa kwe-H-Ru-Cl akukafaneli ngokupheleleko, nge-engele engaba ngu-175° ukusuka ku-triphenylphosphine ligand. Amabanga we-athomu nobude bebhondi kufakwe kuThebuli 1.
I-NMR spectrum ye-Ru-2. a) Indawo ye-hydride ye-1H NMR spectrum etjengisa isignali ye-Ru-H dt. b) 31 P{ 1 H} NMR spectrum etjengisa amatshwayo avela ku-triphenylphosphine (oluhlaza okwesibhakabhaka) kanye ne-POP ligand (okuluhlaza).
Isakhiwo se-Ru-2. Ama-ellipsoid womtjhiso atjengiswa ngethuba elingama-70%. Ukucacisa, ama-athomu we-cocrystalline benzene ne-hydrogen kukhabhoni ashiywe.
Ukuhlola ikghono lama-complex wokukhipha i-formic acid, ubujamo bokuphendula kwakhethwa lapho ama-PNP-clamp complex (isib., i-Ru-MACHO-BH) bekasebenza khulu15. Ukukhipha i-hydrogenation ye-0.5 ml (13.25 mmol) ye-formic acid kusetjenziswa i-0.1 mol% (1000 ppm, 13 μmol) ye-ruthenium complex Ru-1 nofana i-Ru-2 kusetjenziswa i-1.0 ml (5.35 mmol) ionic liquid (IL) BMIM OAc (ithebula 2); Umfanekiso 4);
Ukuthola izinga, ukusabela kwathoma kwenziwa ngokusebenzisa i-precursor adduct [RuHCl(PPh3)3]·toluene. Ukusabela kwenziwa emazingeni womtjhiso ukusuka ku-60 ukuya ku-90 °C. Ngokuya ngokutjheja okulula, i-complex beyingakghoni ukuncibilika ngokupheleleko ku-IL ngitjho nanyana ivuselelwa isikhathi eside emazingeni womtjhiso angama-90°C, kodwana ukuncibilika kwenzeka ngemva kokungeniswa kwe-formic acid. Ku-90°C, ukutjhuguluka kwe-56% (TOF = 3424 h-1) kwafezwa ngaphakathi kwemizuzu eli-10 yokuthoma, begodu ukutjhuguluka okulinganiselweko (97%) kwafezwa ngemva kwama-awa amathathu (ukungena 1). Ukwehlisa amazinga womtjhiso ukuya ku-80 °C kwehlisa ukutjhuguluka ngaphezu kwesigamu ukuya ku-24% ngemva kwemizuzu eli-10 (i-TOF = 1467 h-1, ukungena 2), okuragela phambili nokwehlisa kube yi-18% no-18% ku-70 °C no-60 °C, ngokulandelana 6% (ukungena 3 no-4). Kizo zoke iimeko, akukho sikhathi sokuthoma esitholakeleko, okusikisela bona umtjhugululi kungaba mhlobo ophendulako nofana ukutjhuguluka kwemihlobo ephendulako msinyana khulu ukobana ingatholwa ngokusebenzisa isethi yedatha le.
Ngemva kokuhlolwa kwe-precursor, i-Ru-POP clamp complexes i-Ru-1 ne-Ru-2 yasetjenziswa ngaphasi kweemeko ezifanako. Ku-90°C, ukutjhuguluka okuphezulu kwabonakala khonokho. I-Ru-1 ifinyelele ukutjhuguluka okungu-74% ngaphakathi kwemizuzu eli-10 yokuthoma yokuhlola (i-TOFmax = 4525 h-1, ukungena 5). I-Ru-2 itjengise umsebenzi omncani kodwana ongatjhugulukiko, ikhuthaza ukutjhuguluka okungu-60% ngaphakathi kwemizuzu eli-10 (TOFmax = 3669 h-1) nokutjhuguluka okupheleleko ngaphakathi kwemizuzu ema-60 (>99%) (ukungena 9). Kuyaphawuleka bona i-Ru-2 iphakeme khulu kunensimbi eyandulelako kanye ne-Ru-1 ekuguqulweni okupheleleko. Ngalokho-ke, ngesikhathi isandulela sensimbi ne-Ru-1 banamanani afanako we-TOFoverall ekupheleni kokuphendula (330 h-1 kanye ne-333 h-1, ngokulandelana), i-Ru-2 ine-TOFoverall ye-1009 h-1.
I-Ru-1 ne-Ru-2 zabe sezitjhugululwa izinga lokutjhisa lapho izinga lokutjhisa lehliswa khona kancanikancani nge-10 °C ukuya ku-60 °C (Umfanekiso 3). Nangabe ku-90°C i-complex itjengisa ukusebenza kwamsinyana, ukutjhuguluka okupheleleko kwenzeka kungakapheli i-awa, khona-ke emazingeni womtjhiso aphasi umsebenzi wehla khulu. Ukutjhuguluka kwe-Py-1 bekungu-14% no-23% ngemva kwemizuzu eli-10 ku-80°C no-70°C, ngokulandelana, begodu ngemva kwemizuzu ema-30 kwakhuphuka kwaba ngu-79% no-73% (okungena 6 no-7). Kokubili ukuhlolwa kutjengise izinga lokutjhuguluka elingu-≥90% kungakapheli ama-awa amabili. Ukuziphatha okufanako kwabonwa ku-Ru-2 (okungena 10 no-11). Ngokuthakazelisako, i-Ru-1 beyibusa kancani ekupheleni kokusabela ku-70 °C nge-TOF epheleleko ye-315 h-1 nayiqathaniswa ne-292 h-1 ye-Ru-2 kanye ne-299 h-1 ye-precursor yensimbi.
Ukwehla okunye kwamazinga womtjhiso ukuya ku-60 °C kwabangela bona kungabi nokutjhuguluka okubonwako ngesikhathi semizuzu ema-30 yokuthoma yokuhlola. I-Ru-1 beyingasebenzi khulu emazingeni womtjhiso aphasi khulu ekuthomeni kokuhlola begodu ngemva kwalokho yakhuphula ukusebenza, okutjengisa isidingo sesikhathi sokusebenza lapho i-Ru-1 precatalyst itjhugululwa ibe ziinhlobo ezisebenzako. Nanyana lokhu kungenzeka kiwo woke amazinga womtjhiso, imizuzu eli-10 ekuthomeni kokuhlola bekungakaneli ukuthola isikhathi sokusebenza emazingeni womtjhiso aphezulu. Ukuziphatha okufanako kwatholakala ku-Ru-2. Ku-70 no-60 °C, akukho ukutjhuguluka okwabonwa ngesikhathi semizuzu eli-10 yokuthoma yokuhlola. Kuqakathekile ukutjheja bona kizo zombili iimhloliso, ukwakheka kwekhabhoni monokisayidi akuzange kubonakale ngaphakathi komkhawulo wokutholwa kwethulusi lethu (<300 ppm), lapho i-H2 ne-CO2 bekuyimikhiqizo kwaphela ebonwe.
Ukumadanisa imiphumela ye-formic acid dehydrogenation etholwe ngaphambilini esiqhemeni sokusebenza, esimele ubujamo bezobuciko nokusebenzisa ama-Ru-PNP clamp complexes, kutjengise bona i-Ru-POP clamp esanda kwenziwa inomsebenzi ofana ne-PNP counterpart yayo 15. Lokha i-clamp i-PNP ifinyelele ama-RPM we-RPM we-50-160-160-100-160 h emhlolweni omutjha, esiqhemeni esitjha I-POP clamp ifinyelele inani elifanako le-TOFovertal le-326 h-1, begodu amanani we-TOFmax we-Ru-1 ne-1590 h-1 abonwa. ngokulandelana, ngu-1988 h-1 no-1590 h-1. I-Ru-2 ngu-1 ku-80 °C, i-Ru-1 ngu-4525 h-1 begodu i-Ru-1 ngu-3669 h-1 ku-90 °C, ngokulandelana.
Ukuhlolwa kwamazinga womtjhiso we-formic acid dehydrogenation kusetjenziswa i-Ru-1 ne-Ru-2. Iimeko: 13 µmol catalyst, 0.5 ml (13.25 mmol) formic acid, 1.0 ml (5.35 mmol) BMIM OAc.
I-NMR isetjenziselwa ukuzwisisa iindlela zokuphendula. Njengombana kunomehluko oqakathekileko khulu ku-2JH-P hlangana nama-hydride nama-phosphine ligands, umnqopho wesifundo lesi kuse-hydride peak. Ku-Ru-1, iphetheni ye-dt ejayelekileko yeyunithi yokukhipha i-hydrogenation yatholakala ngesikhathi semizuzu ema-60 yokuthoma yokukhipha i-hydrogenation. Nanyana kunokutjhuguluka okukhulu ukusuka ku-−16.29 ukuya ku-−13.35 ppm, ukuhlangana kwayo ne-phosphine kungu-27.2 no-18.4 Hz, ngokulandelana (Umfanekiso 5, I-Peak A). Lokhu kuhambisana nawo woke ama-phosphine amathathu lapho i-hydrogen ligand isebujamweni be-cis begodu kusikisela bona ukubunjwa kwe-ligand kuzinzile ku-IL isikhathi esingange-awa ngaphasi kweemeko zokuphendula ezihlelekileko. Ukutjhuguluka okunamandla kwehla kungabangelwa kuqedwa kwama-ligands ane-chlorine kanye nokwakheka kwama-acetyl-formic acid complexes ahambelana nawo, ukwakheka kwe-in situ kwe-d3-MeCN complex ku-NMR tube, nofana ukwakheka kwama-N-heterocycles ahambelana nawo. wahlathulula. I-Carbene (NHC) complex. Ngesikhathi sokusabela kokukhipha amanzi, ukuqina kwesiginali kwaragela phambili nokwehla, begodu ngemva kwemizuzu eli-180 isiginali azange isabonwa. Kunalokho, kwatholakala amatshwayo amabili amatjha. Eyokuthoma itjengisa iphetheni ecacileko ye-dd eyenzeka ku--6.4 ppm (isiqongo B). I-doublet ine-coupling ekulu engaba yi-130.4 Hz, okutjengisa bona enye yamayunithi we-phosphine ithuthe ngokuya nge-hydrogen. Lokhu kungatjho bona i-POP clamp ihlelwe kabutjha ibe yi-κ2-P,P. Ukuvela kwalokhu okuyinkimbinkimbi ngemva kwesikhathi sokuvuselela kungatjengisa bona umhlobo lo urholela ekutheni kube neendlela zokungasebenzi ngokukhamba kwesikhathi, okwenza bona kube ne-catalyst sink. Ngakelinye ihlangothi, ukutjhuguluka okuphasi kwamakhemikhali kutjengisa bona kungaba mhlobo we-dihydrogen15. Isiqongo sesibili esitjha sitholakala ku--17.5 ppm. Nanyana ukugoqa kwayo kungaziwa, sikholelwa bona yi-triplet ene-coupling encani ye-17.3 Hz, okutjengisa bona i-hydrogen ligand ibophelela kwaphela ku-phosphine ligand ye-POP clamp, okutjengisa nokukhutjhwa kwe-triphenylphosphine (i-peak C). Ingathathelwa indawo ngenye i-ligand, njengeqembu le-acetyl nofana i-NHC eyakhiwe endaweni yayo ukusuka emanzini we-ionic. Ukuhlukaniswa kwe-PPh3 kubuye kutjengiswe yi-singlet eqinileko ku--5.9 ppm. ku-31P{1H} spectrum ye-Ru-1 ngemva kwemizuzu eli-180 ku-90 °C (qala ilwazi elengeziweko).
Isifunda se-hydride se-1H NMR spectrum ye-Ru-1 ngesikhathi sokukhipha i-hydrogenation ye-formic acid. Ubujamo bokuphendula: 0.5 ml ye-formic acid, 1.0 ml ye-BMIM OAc, i-13.0 µmol catalyst, 90 °C. I-NMR yathathwa ku-MeCN-d 3, 500 μl ye-deuterated solvent, pheze i-10 μl yomxube wokusabela.
Ukuqinisekisa ubukhona bemihlobo esebenzako erherhweni lokukhuthaza, ukuhlaziywa kwe-Ru-1 nge-high resolution mass spectrometry (HRMS) kwenziwa ngemva kokujovwa kwe-formic acid imizuzu eli-10 ku-90 °C. Lokhu kuveza ubukhona bemihlobo engenayo i-chlorine ligand precatalyst emxubeni wokusabela. kanye nama-NHC amabili, izakhiwo zawo ezitjengiswa emfanekisweni 6. I-HRMS spectrum ehambelana nayo ingabonwa emfanekisweni wokungezelela 7.
Ngokuya ngaledatha, siphakamisa indlela yokusabela ngaphakathi kwe-intrasphere efana naleyo ehlongozwe ngu-Beller, lapho ama-N-methylated PNP clamps akhuthaza ukusabela okufanako. Iimhloliso ezingezelelweko ngaphandle kwamanzi we-ionic azange zitjengise nanyana ngimuphi umsebenzi, njeke ukuzibandakanya kwazo ngokunqophileko kubonakala kutlhogeka. Sicabanga bona ukusebenza kwe-Ru-1 ne-Ru-2 kwenzeka ngokuhlukaniswa kwe-chloride kulandele ukungezelelwa kwe-NHC okungenzeka nokuhlukaniswa kwe-triphenylphosphine (Isikimu 1a). Lokhu kusebenza kiyo yoke imihlobo sele kubonwe ngaphambilini kusetjenziswa i-HRMS. I-IL-acetate yisisekelo esinamandla se-Bronsted kune-formic acid begodu ingakhipha amaprothoni ngamandla i-latter35. Sicabanga bona ngesikhathi somjikelezo we-catalytic (Isikimu 1b), imihlobo esebenzako A ene-NHC nofana i-PPh3 ihlanganiswa nge-formate ukwakha imihlobo B. Ukuhlelwa kabutjha kwe-complex ibe yi-C ekugcineni kuphumela ekukhutjhweni kwe-CO2 kanye ne-trans-dihydrogen complex D. ukwakha i-dihydro complex E kuyafana nesinyathelo esiqakathekileko esiphakanyiswe ngu-Beller ngokusebenzisa i-N-methylated PNP clamp homologues. Ukungezelela, i-analogue ye-EL = PPh3 eyinkimbinkimbi yenziwa ngaphambilini ngokusabela kwe-stoichiometric kusetjenziswa i-Ru-1 emmoyeni we-hydrogen ngemva kokukhipha i-chloride nge-sodium salt. Ukususwa kwe-hydrogen nokuhlanganiswa kwe-formate kunikela nge-A begodu kuqeda umjikelezo.
Indlela yokuphendula ngaphakathi kwe-formic acid dehydrogenation ngokusebenzisa i-fixing complex i-Ru-POP Ru-1 iyaphakanyiswa.
I-complex etja [RuHCl(iPr-dbfphos)(PPh3)] yenziwe. I-complex beyibonakala nge-NMR, i-ATRIR, i-EA kanye nokuhlaziywa kwe-X-ray kwe-single crystals. Siphinde sibike ukusetjenziswa kokuthoma okuphumeleleko kwe-Ru-POP pincer complexes ekukhipheni i-hydrogenation ye-formic acid ibe yi-CO2 ne-H2. Nanyana i-precursor yensimbi ifinyelele umsebenzi ofanako (bekufikela ku-3424 h-1), i-complex ifinyelele imvamisa ephezulu yokujika efika ku-4525 h-1 ku-90 °C. Ngaphezu kwalokho, ku-90 °C, i-complex etja [RuHCl(iPr-dbfphos)(PPh3)] ifinyelele isikhathi esipheleleko sokundiza (1009 h-1) ukuqeda i-formic acid dehydrogenation, okuphezulu khulu kunaleyo ye-metal precursor (330 h-1). kanye ne-complex ebikwe ngaphambilini [RuHCl(xantphos)(PPh3)] (333 h-1). Ngaphasi kwemibandela efanako, ukusebenza kuhle kwe-catalytic kuyafana ne-Ru-PNP clamp complex. Idatha ye-HRMS itjengisa ubukhona be-carbene complex emhlanganisweni wokusabela, nanyana kunjalo ngamanani amancani. Njenganje sifunda ngemiphumela yokukhuthaza yama-carbene complexes.
Yonke idatha etholwe namkha ehlaziywe ngesikhathi sesifundo lesi ifakwe esihlokweni esigadangisiweko [kanye namafayela wolwazi asekelako].
U-Azarpour A., ​​  Suhaimi S., Zahedi G. no-Bahadori A. Ukubuyekezwa kokutlhayela kwemithombo yamandla avuselelekako njengomthombo othembisako wamandla wesikhathi esizako. I-Arabhu. J. Isayensi. usonjiniyera. 38, 317–328 (2013).
U-Moriarty P. no-Honery D. Ngiyiphi ikghono lephasi loke lamandla avuselelekako? ukukhwezelela. ukusekela. Energy Rev 16, 244–252 (2012).
U-Rao, u-PC no-Yoon, M. Iinhlelo ezingaba khona ezithwala i-hydrogen (i-Lohc): ukubuyekezwa kwentuthuko yakamuva. Amandla 13, 6040 (2020).
U-Niermann, M., u-Beckendorf, A., u-Kaltschmitt, M. no-Bohnhoff, K. Iinthwali ze-hydrogen eziphilako (i-LOHC) – ukuhlolwa okusekelwe emakhemikhali nezomnotho. ubujamo beentjhabatjhaba. J. Amandla we-hydrogen. 44, 6631–6654 (2019).
U-Teichmann, D., u-Arlt, W., u-Wasserscheid, P. no-Freimann, R. Imithombo yamandla yesikhathi esizako esekelwe kuma-hydrogen carriers we-liquid organic (LOHC). ibhoduluko lamandla. isayensi. 4, 2767–2773 (2011).
U-Niermann, M., u-Timmerberg, S., u-Drunert, S. no-Kaltschmitt, M. Iinthuthi ze-hydrogen eziphilako ezimanzi nezinye iindlela zokuthutha i-hydrogen evuselelekako yamazwe ngamazwe. ukukhwezelela. ukusekela. Energy Ed. 135, 110171 (2021).
U-Rong Y. nabanye. Ukuhlaziywa kwezobuchwepheshe nezomnotho kwamazwe ngamazwe kokugcinwa nokuthuthwa kwe-hydrogen ukusuka esikhungweni sokukhiqiza i-hydrogen ukuya esiteshini sokukhiqiza i-hydrogen. J. Amandla we-hydrogen. 1–12 https://doi.org/10.1016/j.ijhydene.2023.01.187 (2023).
Guo, J. et al. I-formic acid njengendlela yokugcina i-hydrogen ebhodini: ukuthuthukiswa kwama-catalysts wensimbi ehle khulu yokusabela kokukhipha i-hydrogen. Seuss Chemistry Chemistry. 14, 2655–2681 (2021).
U-Muller, K., Brooks, K., no-Autry, T. Ukugcinwa kwe-hydrogen ku-formic acid: ukumadanisa iindlela zokusebenza. Isibaseli samandla. 31, 12603–12611 (2017).
U-Wang, Z., u-Lu, u-SM, u-Li, u-J., u-Wang, u-J. no-Li, Q. I-Iridium complex ene-N,N'-diimine ligand inomsebenzi ongakaze ubonwe we-formic acid dehydrogenation emanzini. Ikhemikhali. – I-EURO. J. 21, 12592–12595 (2015).
U-Hong D. nabanye. Umphumela wokusebenzisana we-heterobinuclear IrIII-MII complexes ekukhutjhweni kwe-H2 ngesikhathi sokukhipha i-hydrogenation ye-formic acid emanzini. Into engaphiliko. Ikhemikhali. 59, 11976–11985 (2020).
U-Fink K., u-Laurenci GA kanye nesikhuthazi esihle khulu sokukhipha i-rhodium-catalyzed dehydrogenation ye-formic acid emanzini. I-EURO. J.Inorg. Ikhemikhali. 2381–2387 (2019).
Seraj, JJA, et al. I-catalyst esebenzako yokukhipha i-hydrogenation ye-formic acid ehlanzekileko. Nat. thintana. 7, 11308 (2016).
U-Piccirelli L. et al. Ukusetjenziswa kwe-CO2 nge-hydrogenation-dehydrogenation ngokusebenzisa i-Ru-PNP/ionic liquid system. J. Am. Isifebe. 145, 5655–5663 (2023).
U-Belinsky EA et al. Ukukhipha i-hydrogenation ye-formic acid nge-Lewis acid kusetjenziswa i-iron catalyst phezu kwe-Pinzer. J. Am. Isifebe. 136, 10234–10237 (2014).
U-Henriks V., u-Juranov I., u-Autissier N. no-Laurenci G. Ukukhipha i-hydrogenation ye-formic acid kuma-catalysts we-Ru-TPPTS afanako: ukwakheka kwe-CO okungafunekiko nokususwa kwayo ngepumelelo nge-PROX. isikhuthazi. 7, 348 (2017).
U-Filonenko GA njll. Ukwenza i-hydrogenation esebenzako nebuyela emuva kwe-carbon dioxide ibe yi-formate kusetjenziswa i-ruthenium catalyst PNP-Pinzer. Ikhemistri Ikhemistri yekati. 6, 1526–1530 (2014).
Hull, J. et al. Ukugcinwa kwe-hydrogen okubuyiselwa emuva ngokusebenzisa i-carbon dioxide kanye nama-proton-switched iridium catalysts eendaweni ezinamanzi emazingeni womtjhiso aphakathi nendawo. Nat. Ikhemikhali. 4, 383–388 (2012).
U-Wei, D. nabanye. I-Mn-Pincer complex isetjenziselwa ukubuyela emuva kwe-hydrogenation ye-carbon dioxide ibe yi-formic acid lokha nakune-lysine. Nat. amandla. 7, 438–447 (2022).
U-Piccirilli L., u-Pinheiro DL no-Nielsen M. Pincer Ithuthuko yakamuva eensetjenzisweni zensimbi yokutjhuguluka kwentuthuko esimemeko. isikhuthazi. 10, 773 (2020).
U-Wei, D., Junge, H. no-Beller, M. Iinhlelo ze-amino acid zokubamba i-carbon dioxide nokusetjenziswa kwe-catalytic ukukhiqiza i-formate. Ikhemikhali. isayensi. 12, 6020–6024 (2021).
U-Subramanian M. et al. I-ruthenium ejwayelekileko nekhethiweko yokudlulisa i-hydrogenation, i-deuteration kanye ne-methylation yamakhompawundi asebenzako nge-methanol. J. Cutler. 425, 386–405 (2023).
U-Ni Z., u-Padilla R., u-Pramanik R., u-Jorgensen MSB no-Nielsen M. Ukuhlanganiswa kwe-ethanol ukuya ku-ethyl acetate ngaphandle kwe-base ne-acceptor kusetjenziswa ama-PNP complexes. I-span ka-Dalton. 52, 8193–8197 (2023).
U-Fu, S., u-Shao, Z., u-Wang, Y., no-Liu, Q. Ukuthuthukiswa kwe-ethanol okukhuthazwa yi-Manganese ukuya ku-1-butanol. J. Am. Isifebe. 139, 11941–11948 (2017).