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I-Formic acid yenye yezona zinto zithembisayo zokugcina i-hydrogen engamanzi ixesha elide. Apha sibonisa uthotho lwee-complexes ezintsha ze-ruthenium clamp ezinefomula eqhelekileyo [RuHCl(POP)(PPh3)] sisebenzisa ii-ligands ze-xanthos-type tridentate POP clamp ezifumaneka kurhwebo okanye ezenziwe lula. Sisebenzise ezi complexes ukukhupha i-formic acid ukuvelisa i-CO2 kunye ne-H2 phantsi kweemeko ezithambileyo, ezingenayo i-reflux sisebenzisa i-ionic liquid BMIM OAc (1-butyl-3-methylimidazolium acetate) njenge-solvent. Ngokwembono ye-maximum turnover frequency, eyona catalyst isebenzayo yi-[RuHCl(xantphos)(PPh3)]Ru-1 complex eyaziwa kwiincwadi, ene-maximum turnover frequency ye-4525 h-1 kwi-90 °C imizuzu eli-10. Izinga lokuguqulwa emva kokuguqulwa yayiyi-74%, kwaye ukuguqulwa kwagqitywa kwiiyure ezi-3 (>98%). Kwelinye icala, i-catalyst enentsebenzo engcono kakhulu iyonke, inoveli [RuHCl(iPr-dbfphos)(PPh3)]Ru-2 complex, ikhuthaza ukuguqulwa okupheleleyo ngaphakathi kweyure e-1, nto leyo ekhokelela kwizinga lokujika lilonke le-1009 h-1. Ukongeza, umsebenzi we-catalytic nawo wabonwa kumaqondo obushushu afikelela kwi-60 °C. Kwisigaba segesi, yi-CO2 kunye ne-H2 kuphela ezabonwayo; i-CO ayizange ifunyanwe. I-high-resolution mass spectrometry ibonise ubukho be-N-heterocyclic carbene complexes kumxube we-reaction.
Isabelo semarike esikhulayo samandla avuselelekayo kunye nokwahluka kwawo kukhokelele kwimfuno yetekhnoloji yokugcina amandla emizi-mveliso kumacandelo amandla, ubushushu, amashishini kunye nezothutho1,2. I-Hydrogen ithathwa njengenye yezona zithwali zamandla zininzi3, kwaye izithwali ze-hydrogen ze-organic ezingamanzi (ii-LOHC) kutshanje ziye zaba yindawo ephambili kuphando, zinika isithembiso sokugcina i-hydrogen kwimo elungiswa ngokulula ngaphandle kweengxaki ezinxulumene noxinzelelo okanye ubuchwepheshe be-cryogenic4. ,5,6. Ngenxa yeempawu zazo zomzimba, uninzi lweziseko zothutho ezikhoyo zepetroli kunye nezinye izibaso ezingamanzi zinokusetyenziselwa ukuthutha i-LOHC7,8. Iimpawu zomzimba ze-formic acid (FA) zenza ukuba ibe ngumviwa othembisayo wokugcina i-hydrogen enomxholo wobunzima be-hydrogen oyi-4.4%9,10. Nangona kunjalo, iinkqubo ze-catalytic ezipapashiweyo zokukhupha i-formic acid zihlala zifuna ukusetyenziswa kwezinyibilikisi ze-organic eziguquguqukayo, amanzi okanye i-formic acid ecocekileyo,11,12,13,14 okunokubangela ukusetyenziswa kweendlela zokwahlula umphunga we-solvent ezifana nokuxinana, okunokubangela iingxaki kwizicelo zabathengi. izicelo, umthwalo owongezelelweyo. Le ngxaki ingoyiswa ngokusebenzisa izinyibilikisi ezinexinzelelo lomphunga oluncinci, njengee-ionic liquids. Ngaphambili, iqela lethu elisebenzayo libonise ukuba i-ionic liquid butylmethylimidazolium acetate (BMIM OAc) sisinyibilikisi esifanelekileyo kule reaction sisebenzisa i-Ru-PNP Ru-MACHO type 15 efumaneka kurhwebo. Umzekelo, sibonise i-FA dehydrogenation kwinkqubo yokuhamba rhoqo sisebenzisa i-BMIM OAc, sifikelela kwi-TON engaphezulu kwe-18,000,000 kwi-95°C. Nangona ezinye iinkqubo ziye zafumana i-TON ephezulu ngaphambili, ezininzi ziye zathembela kwi-volatile organic solvents (ezifana ne-THF okanye i-DMF) okanye izongezo ezisetyenzisiweyo (ezifana neziseko). Ngokwahlukileyo koko, umsebenzi wethu usebenzisa ii-non-volatile ionic liquids (ILs) kwaye akukho zongezo.
UHazari noBernskoetter baxele ngokuncitshiswa kwe-formic acid (FA) kwi-80 °C besebenzisa i-Fe-PNP catalyst phambi kwe-dioxane kunye ne-LiBF4, bafumana inani elimangalisayo lokujika (TON) elimalunga ne-1,000,00016. ULaurenci usebenzise i-Ru(II)- complex catalyst TPPPTS kwinkqubo yokuncitshiswa kwe-FA eqhubekayo. Le ndlela yabangela ukuncitshiswa kwe-FA phantse ngokupheleleyo kunye neempawu ezincinci ze-CO ezifunyenwe kwi-80 °C17. Ukuze baqhubele phambili eli candelo, uPidko ubonise ukuncitshiswa kwe-FA okuguquguqukayo kusetyenziswa ii-catalysts ze-Ru-PNP clamp kwi-DMF/DBU kunye ne-DMF/NHex₃ mixtures, befikelela kwi-TON values ​​​​eziyi-310,000 ukuya kwi-706,500 kwi-90 °C18. UHull, uHimeda kunye noFujita bafunde i-binuclear Ir complex catalyst apho i-KHCO3 kunye ne-H2SO4 zanikelwa khona, zitshintshana nge-CO2 hydrogenation kunye ne-FA dehydrogenation. Iinkqubo zabo zifikelele kwi-TONs ezingaphezulu kwe-3,500,000 kunye ne-308,000 ngokulandelelanayo kwi-hydrogenation kwi-30°C, i-CO2/H2 (1:1), uxinzelelo lwe-bar enye kunye ne-dehydrogenation phakathi kwe-60 kunye ne-90°C19. USponholz, uJunge kunye noBeller baphuhlise i-Mn-PNP complex ye-reversible CO2 hydrogenation kunye ne-FA dehydrogenation kwi-90°C20.
Apha sisebenzise indlela ye-IL, kodwa endaweni yokusebenzisa i-Ru-PNPs, sihlolisise ukusetyenziswa kwee-catalysts ze-Ru-POP, ezingakhange ziboniswe ngaphambili kule nkalo.
Ngenxa yokudibanisa kwazo kakuhle i-metal-ligand (MLC), ii-amino-PNP clamp complexes ezisekelwe kwiingcamango ze-Noyori-type kunye namaqela e-amino functional asebenzisanayo 21 (njenge-Ru-MACHO-BH) zihlala zithandwa kakhulu kwimisebenzi ethile emincinci ye-molecule. Imizekelo edumileyo ibandakanya i-CO22, i-hydrogenation ye-alkenes kunye ne-carbonyls, i-transfer hydrogenation23 kunye ne-acceptorless dehydrogenation ye-alcohols24. Kuye kwaxelwa ukuba i-N-methylation ye-PNP clamp ligands inokumisa ngokupheleleyo umsebenzi we-catalyst25, nto leyo enokuchazwa yinyani yokuba ii-amines zisebenza njengemithombo ye-proton, nto leyo iyimfuneko ebalulekileyo ngexesha lomjikelo we-catalytic usebenzisa i-MLC. Nangona kunjalo, umkhwa ochaseneyo kwi-formic acid dehydrogenation ubonwe kutshanje nguBeller, apho ii-N-methylated Ru-PNP complexes zibonise i-catalytic dehydrogenation engcono ye-formic acid kunezinye zazo ezingenamethylated26. Ekubeni i-complex yangaphambili ingenakuthatha inxaxheba kwi-MLC ngeyunithi ye-amino, oku kuthetha ngamandla ukuba i-MLC, kwaye ngenxa yoko iyunithi ye-amino, inokudlala indima engabalulekanga kangako kwiinguqu ezithile (ze-hydrogenation) kunokuba bekucingelwa ngaphambili.
Xa kuthelekiswa nee-POP clamps, ii-ruthenium complexes zee-POP clamps azikafundwa ngokwaneleyo kule ndawo. Ii-POP ligands bezisoloko zisetyenziswa kakhulu kwi-hydroformylation, apho zisebenza njenge-chelating ligands endaweni ye-characteristic bidentate bite angle emalunga ne-120° kwi-clamping ligands, eziye zasetyenziswa ukuphucula ukukhetha kwiimveliso ezithe ngqo nezinamasebe27,28,29. Ukusukela ngoko, ii-Ru-POP complexes azizange zisetyenziswe rhoqo kwi-hydrogenation catalysis, kodwa imizekelo yomsebenzi wazo kwi-transfer hydrogenation ibikwe ngaphambili30. Apha sibonisa ukuba i-Ru-POP complex sisisixabisi esisebenzayo sokukhuculwa kwe-formic acid, siqinisekisa ukufunyanwa kukaBeller kokuba iyunithi ye-amino kwi-classical Ru-PNP amine catalyst ayibalulekanga kangako kule mpendulo.
Uphononongo lwethu luqala ngokwenziwa kwee-catalysts ezimbini eziqhelekileyo ngefomula eqhelekileyo [RuHCl(POP)(PPh3)] (Umzobo 1a). Ukutshintsha isakhiwo se-steric kunye ne-elektroniki, i-dibenzo[b,d]furan ikhethwe kwi-4,6-bis(diisopropylphosphino) ethengiswayo (Umzobo 1b) 31. Ii-catalysts ezifundwe kulo msebenzi zenziwe kusetyenziswa indlela eqhelekileyo eyenziwe yiWhittlesey32, kusetyenziswa i-[RuHCl(PPh3)3]•toluene33 adduct njenge-precursor. Xuba i-metal precursor kunye ne-POP clamp ligand kwi-THF phantsi kweemeko ezingqongqo ze-anhydrous kunye ne-anaerobic. I-reaction yayihamba notshintsho olukhulu lombala ukusuka kumfusa omnyama ukuya kumthubi kwaye yanika imveliso ecocekileyo emva kweeyure ezi-4 ze-reflux okanye iiyure ezingama-72 ze-reflux kwi-40°C. Emva kokususa i-THF kwi-vacuo nokuhlanjwa kabini nge-hexane okanye i-diethyl ether, i-triphenylphosphine isusiwe ukuze imveliso ibe ngumgubo otyheli onesivuno esiphezulu.
Ukwenziwa kwee-complexes ze-Ru-1 kunye ne-Ru-2. a) Indlela yokwenziwa kwee-complexes. b) Ulwakhiwo lwe-complex edityanisiweyo.
I-Ru-1 sele isaziwa kwiincwadi32, kwaye ukuchazwa ngakumbi kugxile kwi-Ru-2. I-1H NMR spectrum ye-Ru-2 iqinisekisile ukwakheka kwe-cis ye-athomu ye-phosphine kwi-ligand yesibini se-hydride. I-peak dt plot (Umfanekiso 2a) ibonisa ii-constants ze-2JP-H ze-28.6 kunye ne-22.0 Hz, ezikwinqanaba elilindelekileyo leengxelo zangaphambili32. Kwi-spectrum ye-31P{1H} edityanisiweyo ye-hydrogen (Umfanekiso 2b), i-constant ye-2JP-P ye-coupled constant ye-27.6 Hz yabonwa, iqinisekisa ukuba zombini ii-clamp ligand phosphines kunye ne-PPh3 ziyi-cis-cis. Ukongeza, i-ATR-IR ibonisa ibhendi yokunwebeka ye-ruthenium-hydrogen kwi-2054 cm-1. Ukuze kucaciswe ngakumbi ngesakhiwo, i-Ru-2 complex yenziwe i-crystallized ngokusasazeka komphunga kubushushu begumbi kunye nomgangatho owaneleyo kwizifundo ze-X-ray (Umzobo 3, Itheyibhile eyoNgezelelweyo 1). Iyenza i-crystallized kwinkqubo ye-triclinic yeqela lesithuba i-P-1 kunye neyunithi enye ye-cocrystalline benzene ngeyunithi nganye. Ibonisa i-angle ebanzi ye-P-Ru-P occlusal ye-153.94°, ebanzi kakhulu kune-angle ye-130° occlusal ye-bidentate DBFphos34. Kwi-2.401 kunye ne-2.382 Å, ubude be-bond ye-Ru-PPOP bude kakhulu kunobude be-bond ye-Ru ukuya kwi-PPh3 ye-2.232 Å, enokuba ngumphumo we-angle ebanzi ye-backbone snack ye-DBFphos ebangelwa yi-5-ring yayo ephakathi. I-geometry yeziko lesinyithi ngokusisiseko yi-octahedral ene-angle ye-O-Ru-PPh3 ye-179.5°. Ulungelelwaniso lwe-H-Ru-Cl alukho mgca ngokupheleleyo, lune-engile emalunga ne-175° ukusuka kwi-ligand ye-triphenylphosphine. Imigama ye-atomic kunye nobude bebhondi zidweliswe kwiTheyibhile 1.
I-NMR spectrum ye-Ru-2. a) Ummandla we-Hydride we-1H NMR spectrum ebonisa isignali ye-Ru-H dt. b) I-31 P{ 1 H} I-NMR spectrum ebonisa imiqondiso evela kwi-triphenylphosphine (eluhlaza okwesibhakabhaka) kunye ne-POP ligand (eluhlaza).
Ulwakhiwo lwe-Ru-2. Ii-ellipsoids zobushushu ziboniswa ngamathuba angama-70%. Ukuze kucace, ii-athomu ze-benzene kunye ne-hydrogen ezikwikhabhoni azikho.
Ukuvavanya amandla ee-complexes okukhupha i-hydrogen kwi-formic acid, iimeko zokusabela zikhethiwe phantsi kwazo apho ii-complexes ze-PNP-clamp ezifanelekileyo (umz., i-Ru-MACHO-BH) zazisebenza kakhulu15. Ukukhupha i-hydrogen kwi-0.5 ml (13.25 mmol) i-formic acid kusetyenziswa i-0.1 mol% (1000 ppm, 13 µmol) i-ruthenium complex i-Ru-1 okanye i-Ru-2 kusetyenziswa i-1.0 ml (5.35 mmol) ionic liquid (IL) i-BMIM OAc (umfanekiso wetafile) 2; Umfanekiso 4);
Ukuze kufunyanwe umgangatho, ukusabela kwenziwa kuqala kusetyenziswa i-precursor adduct [RuHCl(PPh3)3]·toluene. Ukusabela kwenziwa kubushushu obuvela kuma-60 ukuya kuma-90 °C. Ngokwembono elula, i-complex ayinakunyibilika ngokupheleleyo kwi-IL nokuba kuxutywa ixesha elide kubushushu obungama-90 °C, kodwa ukunyibilika kwenzeke emva kokungeniswa kwe-formic acid. Kwi-90 °C, ukuguqulwa kwe-56% (TOF = 3424 h-1) kufezekiswe kwimizuzu eli-10 yokuqala, kwaye ukuguqulwa okuphantse kube yi-quantitative (97%) kufezekiswe emva kweeyure ezintathu (ukungena 1). Ukunciphisa ubushushu ukuya kuma-80 °C kunciphisa ukuguqulwa ngaphezulu kwesiqingatha ukuya kuma-24% emva kwemizuzu eli-10 (TOF = 1467 h-1, ukungena 2), kunciphisa ngakumbi ukuya kwi-18% kunye ne-18% kwi-70 °C kunye nama-60 °C, ngokulandelanayo yi-6% (ukungena 3 kunye no-4). Kuzo zonke iimeko, akukho xesha lokungeniswa elifunyenweyo, nto leyo ebonisa ukuba i-catalyst isenokuba ziintlobo ezisabelayo okanye ukuba ukuguqulwa kweentlobo ezisabelayo kukhawulezile kakhulu ukuba kungafunyanwa kusetyenziswa olu seti lwedatha.
Emva kovavanyo lwangaphambi kovavanyo, ii-complexes ze-Ru-POP clamp Ru-1 kunye ne-Ru-2 zasetyenziswa phantsi kweemeko ezifanayo. Kwi-90°C, ukuguqulwa okuphezulu kwabonwa ngoko nangoko. I-Ru-1 ifumene ukuguqulwa kwe-74% kwimizuzu yokuqala eli-10 yovavanyo (TOFmax = 4525 h-1, ukungena 5). I-Ru-2 ibonise umsebenzi omncinci kodwa oqhubekayo, ikhuthaza ukuguqulwa kwe-60% kwimizuzu eli-10 (TOFmax = 3669 h-1) kunye nokuguqulwa okupheleleyo kwimizuzu engama-60 (>99%) (ukungena 9). Kuyaphawuleka ukuba i-Ru-2 ingaphezulu kakhulu kune-precursor metal kunye ne-Ru-1 kwi-conversion epheleleyo. Ke ngoko, ngelixa i-metal precursor kunye ne-Ru-1 zinexabiso elifanayo le-TOFoverall ekugqityweni kwe-reaction (330 h-1 kunye ne-333 h-1, ngokulandelelana), i-Ru-2 ine-TOFoverall ye-1009 h-1.
I-Ru-1 kunye ne-Ru-2 emva koko zatshintshelwa kutshintsho lobushushu apho ubushushu bancitshiswa kancinci kancinci ngokunyusa kwe-10 °C ukuya kuthi ga kwi-60 °C ubuncinci (Umzobo 3). Ukuba kwi-90 °C i-complex ibonise umsebenzi okhawulezileyo, uguquko oluphantse lwaphela lwenzeka kwiyure enye, ngoko kumaqondo obushushu aphantsi umsebenzi wehla kakhulu. Ukuguqulwa kwe-Py-1 kwaba yi-14% kunye ne-23% emva kwemizuzu eli-10 kwi-80 °C kunye ne-70 °C, ngokulandelanayo, kwaye emva kwemizuzu engama-30 kwanda ukuya kwi-79% kunye ne-73% (ungeniso 6 kunye no-7). Zombini iimvavanyo zibonise izinga lokuguqulwa kwe-≥90% kwiiyure ezimbini. Ukuziphatha okufanayo kwabonwa kwi-Ru-2 (ungeniso 10 kunye no-11). Okunomdla kukuba, i-Ru-1 yayinamandla kancinci ekupheleni kwempendulo kwi-70 °C kunye ne-TOF iyonke ye-315 h-1 xa kuthelekiswa ne-292 h-1 kwi-Ru-2 kunye ne-299 h-1 kwi-precursor yesinyithi.
Ukwehla ngakumbi kobushushu ukuya kuma-60 °C kukhokelele kwinto yokuba akukho kuguqulwa kwabonwayo kwimizuzu engama-30 yokuqala yovavanyo. I-Ru-1 yayingasebenzi kakhulu kubushushu obuphantsi ekuqaleni kovavanyo kwaye kamva yandisa umsebenzi, nto leyo ebonisa imfuneko yexesha lokuqalisa apho i-Ru-1 precatalyst iguqulwa ibe yi-catalytically active species. Nangona oku kunokwenzeka kuwo onke amaqondo obushushu, imizuzu eli-10 ekuqaleni kovavanyo yayinganelanga ukufumanisa ixesha lokuqalisa kwiqondo lobushushu eliphezulu. Ukuziphatha okufanayo kufunyenwe kwi-Ru-2. Kwi-70 kunye ne-60 °C, akukho kuguqulwa kwabonwayo kwimizuzu eli-10 yokuqala yovavanyo. Kubalulekile ukuqaphela ukuba kuzo zombini iimvavanyo, ukwakheka kwe-carbon monoxide akuzange kubonwe ngaphakathi komda wokufumanisa wesixhobo sethu (<300 ppm), kunye ne-H2 kunye ne-CO2 kuphela kweemveliso ezibonweyo.
Ukuthelekiswa kweziphumo ze-formic acid dehydrogenation ezifunyenwe ngaphambili kweli qela lisebenzayo, elimele imeko yangoku kwaye lisebenzisa ii-complexes ze-Ru-PNP clamp, kubonise ukuba i-Ru-POP clamp entsha eyenziweyo inomsebenzi ofana nomlingani wayo we-PNP 15. Ngelixa i-clamp I-PNP ifumene ii-RPM ze-500-1260 h-1 kwiimvavanyo zebhetshi, i-POP clamp entsha ifumene ixabiso elifanayo le-TOFovertal le-326 h-1, kwaye amaxabiso e-TOFmax e-Ru-1 kunye ne-1590 h-1 abonwa. ngokulandelelana, yi-1988 h-1 kunye ne-1590 h-1. I-Ru-2 yi-1 kwi-80 °C, i-Ru-1 yi-4525 h-1 kwaye i-Ru-1 yi-3669 h-1 kwi-90 °C, ngokulandelelana.
Ukuhlolwa kobushushu bokubola kwe-formic acid kusetyenziswa ii-catalysts ze-Ru-1 kunye ne-Ru-2. Iimeko: i-catalyst eyi-13 µmol, i-formic acid eyi-0.5 ml (13.25 mmol), i-1.0 ml (5.35 mmol) i-BMIM OAc.
I-NMR isetyenziselwa ukuqonda iindlela zokusabela. Ekubeni kukho umahluko omkhulu kakhulu kwi-2JH-P phakathi kwe-hydride kunye ne-phosphine ligands, ingqwalasela yolu phononongo ikwi-hydride peak. Kwi-Ru-1, ipatheni eqhelekileyo ye-dt yeyunithi ye-hydrogenation ifunyenwe ngexesha lemizuzu engama-60 yokuqala yokuphelelwa yi-hydrogenation. Nangona kukho utshintsho olukhulu ukusuka kwi-−16.29 ukuya kwi-−13.35 ppm, ii-coupling constants zayo kunye ne-phosphine ziyi-27.2 kunye ne-18.4 Hz, ngokulandelanayo (Umfanekiso 5, i-Peak A). Oku kuhambelana nazo zonke ii-phosphines ezintathu apho i-hydrogen ligand ikwi-cis configuration kwaye icebisa ukuba i-ligand configuration izinzile kancinci kwi-IL malunga neyure enye phantsi kweemeko zokusabela ezilungisiweyo. Utshintsho olunamandla lwe-downfield lunokubangelwa kukususwa kwee-ligands ze-chlorinated kunye nokwenziwa kwee-complexes ze-acetyl-formic acid ezihambelanayo, ukwakheka kwe-d3-MeCN complex kwityhubhu ye-NMR, okanye ukwakheka kwee-N-heterocycles ezihambelanayo. kuchaziwe. I-Carbene (NHC) complex. Ngexesha lokusabela kwe-dehydrogenation, amandla alo mqondiso aqhubeka ehla, kwaye emva kwemizuzu eyi-180 uphawu aluzange lubonwe. Endaweni yoko, kwafunyanwa imiqondiso emibini emitsha. Eyokuqala ibonisa iphethini ecacileyo ye-dd eyenzeka kwi--6.4 ppm (incopho B). I-doublet ine-coupling constant enkulu emalunga ne-130.4 Hz, ebonisa ukuba enye yeeyunithi ze-phosphine ishukumile ngokumalunga ne-hydrogen. Oku kunokuthetha ukuba i-POP clamp ihlelwe ngokutsha ibe yi-κ2-P,P configuration. Ukubonakala kwale complex emva kwexesha kwi-catalysis kunokubonisa ukuba olu hlobo lukhokelela kwiindlela zokucima ngokuhamba kwexesha, zenze i-catalyst sink. Kwelinye icala, utshintsho oluphantsi lweekhemikhali lubonisa ukuba isenokuba yintlobo ye-dihydrogenous15. Incochoyi yesibini entsha ikwi--17.5 ppm. Nangona ukugoba kwayo kungaziwa, sikholelwa ukuba yi-triplet ene-coupling constant encinci ye-17.3 Hz, ebonisa ukuba i-hydrogen ligand ibopha kuphela kwi-phosphine ligand ye-POP clamp, ikwabonisa ukukhululwa kwe-triphenylphosphine (incochoyi C). Ingathathelwa indawo yenye i-ligand, njengeqela le-acetyl okanye i-NHC eyenziwe kwi-situ evela kulwelo lwe-ionic. Ukwahlukana kwe-PPh3 kuboniswa ngakumbi yi-singlet enamandla kwi--5.9 ppm. kwi-31P{1H} spectrum ye-Ru-1 emva kwemizuzu eyi-180 kwi-90 °C (jonga ulwazi olongezelelweyo).
Ummandla weHydride we-1H NMR spectrum yeRu-1 ngexesha lokuphelelwa yi-hydrogenation ye-formic acid. Iimeko zokusabela: i-0.5 ml ye-formic acid, i-1.0 ml ye-BMIM OAc, i-13.0 µmol catalyst, i-90 °C. I-NMR ithathwe kwi-MeCN-d 3, i-500 μl ye-deuterated solvent, malunga ne-10 μl yomxube we-reaction.
Ukuqinisekisa ngakumbi ubukho beentlobo ezisebenzayo kwinkqubo ye-catalytic, uhlalutyo lwe-high resolution mass spectrometry (HRMS) lwe-Ru-1 lwenziwe emva kokufakwa kwe-formic acid imizuzu eli-10 kwi-90 °C. Oku kubonisa ubukho beentlobo ezingenayo i-chlorine ligand precatalyst kumxube we-reaction. kunye nee-complexes ezimbini ze-NHC, izakhiwo zazo eziboniswa kuMfanekiso 6. I-spectrum ye-HRMS ehambelanayo inokubonwa kuMfanekiso oNgezelelweyo 7.
Ngokusekelwe kwezi datha, sicebisa indlela yokusabela ngaphakathi kwe-intrasphere efana naleyo icetywayo nguBeller, apho ii-N-methylated PNP clamps zivuselela impendulo efanayo. Uvavanyo olongezelelweyo oluquka ulwelo lwe-ionic aluzange lubonise msebenzi, ngoko ke ukubandakanyeka kwayo ngokuthe ngqo kubonakala kuyimfuneko. Sicinga ukuba ukusebenza kwe-Ru-1 kunye ne-Ru-2 kwenzeka ngokuhlukana kwe-chloride kulandelwa kukongeza okunokwenzeka kwe-NHC kunye nokuhlukana kwe-triphenylphosphine (Scheme 1a). Olu sebenze kuzo zonke iintlobo luye lwabonwa ngaphambili kusetyenziswa i-HRMS. I-IL-acetate sisiseko seBronsted esomeleleyo kune-formic acid kwaye sinokususa ngamandla i-latter35. Sicinga ukuba ngexesha lomjikelo we-catalytic (Scheme 1b), iintlobo ezisebenzayo ze-A ezithwala i-NHC okanye i-PPh3 zilungelelaniswa nge-formate ukuze zenze iintlobo ze-B. Ukulungiswa kwakhona kwale complex kwi-C ekugqibeleni kuphumela ekukhutshweni kwe-CO2 kunye ne-trans-dihydrogen complex D. I-protonation elandelayo ye-asidi kwi-dihydro complex ene-acetic acid eyenziwe ngaphambili ukuze yenze i-dihydro complex E ifana nenyathelo eliphambili elicetywayo nguBeller esebenzisa ii-homologues ze-N-methylated PNP clamp. Ukongeza, i-analogue ye-complex EL = PPh3 yayisenziwa ngaphambili yi-stoichiometric reaction kusetyenziswa i-Ru-1 kwi-hydrogen atmosphere emva kokukhupha i-chloride ngetyuwa ye-sodium. Ukususwa kwe-hydrogen kunye nokulungelelaniswa kwe-formate kunika i-A kwaye kugqibezele umjikelo.
Indlela yokusabela ngaphakathi kwe-formic acid dehydrogenation isebenzisa i-fixing complex Ru-POP Ru-1 iyacetyiswa.
I-complex entsha [iRuHCl(iPr-dbfphos)(PPh3)] yenziwe. Le complex yabonakaliswa yi-NMR, ATRIR, EA kunye nohlalutyo lwe-X-ray diffraction lweekristale ezingatshatanga. Sikwaxela ukusetyenziswa kokuqala okuphumeleleyo kwe-Ru-POP pincer complexes ekukhutshweni kwe-formic acid kwi-CO2 kunye ne-H2. Nangona i-metal precursor ifumene umsebenzi ofanayo (ukuya kuthi ga kwi-3424 h-1), i-complex ifikelele kwi-frequency ephezulu yokujika ukuya kuthi ga kwi-4525 h-1 kwi-90 °C. Ngaphezu koko, kwi-90 °C, i-complex entsha [iRuHCl(iPr-dbfphos)(PPh3)] ifumene ixesha elipheleleyo lokubhabha (1009 h-1) ukuze igqibezele i-formic acid dehydrogenation, ephezulu kakhulu kuneyo ye-metal precursor (330 h-1). kunye ne-complex echazwe ngaphambili [iRuHCl(xantphos)(PPh3)] (333 h-1). Phantsi kweemeko ezifanayo, ukusebenza kakuhle kwe-catalytic kuyafana noko kwe-Ru-PNP clamp complex. Idatha ye-HRMS ibonisa ukuba kukho i-carbene complex kumxube we-reaction, nangona incinci. Okwangoku sifunda ngemiphumo ye-catalytic ye-carbene complexes.
Yonke idatha efunyenweyo okanye ehlalutyiweyo ngeli xesha lophando ifakiwe kweli nqaku lipapashweyo [kunye neefayile zolwazi ezixhasayo].
UAzarpour A., ​​​​Suhaimi S., Zahedi G. kunye noBahadori A. Uphononongo lokusilela kwemithombo yamandla avuselelekayo njengomthombo othembisayo wamandla kwixesha elizayo. Arab. J. Science. injineli. 38, 317–328 (2013).
UMoriarty P. kunye noHonery D. Yintoni amandla ehlabathi avuselelekayo? hlaziya. inkxaso. Energy Rev 16, 244–252 (2012).
URao, iPC kunye noYoon, M. Iinkqubo ezinokubakho zokuthwala i-hydrogen organic (Lohc) ezingamanzi: uphononongo lwenkqubela phambili yakutshanje. Amandla 13, 6040 (2020).
Niermann, M., Beckendorf, A., Kaltschmitt, M. kunye noBohnhoff, K. Abathwali behydrogen yendalo engamanzi (LOHC) – uvavanyo olusekelwe kwiipropati zeekhemikhali nezoqoqosho. ubuzwe. J. Amandla eHydrogen. 44, 6631–6654 (2019).
Teichmann, D., Arlt, W., Wasserscheid, P. kunye noFreimann, R. Imithombo yamandla yexesha elizayo esekelwe kwiinkampani zehydrogen zendalo ezingamanzi (LOHC). okusingqongileyo kwamandla. isayensi. 4, 2767–2773 (2011).
Niermann, M., Timmerberg, S., Drunert, S. kunye noKaltschmitt, M. Abathwali behydrogen yendalo engamanzi kunye nezinye iindlela zokuthutha ihydrogen evuselelekayo kwihlabathi liphela. uhlaziyo. inkxaso. Energy Ed. 135, 110171 (2021).
URong Y. nabanye. Uhlalutyo lobuchwephesha nolwezoqoqosho lwamazwe ngamazwe lokugcina kunye nokuthuthwa kwe-hydrogen ukusuka kwisityalo sokuvelisa i-hydrogen ukuya kwisikhululo sesiphelo se-hydrogenation. J. Amandla e-hydrogen. 1–12 https://doi.org/10.1016/j.ijhydene.2023.01.187 (2023).
UGuo, J. et al. I-Formic acid njengendlela yokugcina i-hydrogen ekwibhodi: uphuhliso lwee-catalysts zesinyithi ezihle ezifanayo zokusabela kokungabi namanzi. I-Seuss Chemistry Chemistry. 14, 2655–2681 (2021).
Muller, K., Brooks, K., kunye no-Autry, T. Ukugcinwa kwe-hydrogen kwi-formic acid: uthelekiso lweendlela zenkqubo. Amandla e-fuel. 31, 12603–12611 (2017).
UWang, Z., uLu, uSM, uLi, uJ., uWang, uJ. kunye noLi, uQ. I-Iridium complex ene-N,N'-diimine ligand inomsebenzi ophezulu kakhulu wokukhupha i-asidi emanzini. Iikhemikhali. – EURO. J. 21, 12592–12595 (2015).
UHong D. et al. Isiphumo sokusebenzisana kwee-heterobinuclear IrIII-MII complexes ekukhutshweni kwe-catalytic ye-H2 ngexesha lokususwa kwe-hydrogenation ye-formic acid emanzini. Izinto ezingaphiliyo. Iikhemikhali. 59, 11976–11985 (2020).
UFink K., uLaurenci GA kunye nesixhobo esibalulekileyo sokunciphisa i-hydrogenation ye-formic acid emanzini yi-rhodium. EURO. J.Inorg. Chemical. 2381–2387 (2019).
Seraj, JJA, et al. Isincedisi esisebenzayo sokukhupha i-hydrogenation ye-asidi ye-formic ecocekileyo. I-Nat. communicate. 7, 11308 (2016).
UPiccirelli L. et al. I-catalysis yemisebenzi emininzi ye-CO2 hydrogenation-dehydrogenation kusetyenziswa inkqubo ye-Ru-PNP/ionic liquid. J. Am. Bitch. 145, 5655–5663 (2023).
UBelinsky EA et al. Ukususwa kwe-hydrogenation ye-formic acid nge-Lewis acid kusetyenziswa i-iron catalyst kwi-Pinzer support. J. Am. Bitch. 136, 10234–10237 (2014).
UHenriks V., uJuranov I., uAutissier N. kunye noLaurenci G. Ukususwa kwe-formic acid kwi-catalysts zeRu-TPPTS ezifanayo: ukwakheka kwe-CO engafunekiyo kunye nokususwa kwayo ngempumelelo nge-PROX. catalyst. 7, 348 (2017).
IFilonenko GA njl. I-hydrogenation esebenzayo neguqukayo ye-carbon dioxide ibe yi-formate kusetyenziswa i-ruthenium catalyst PNP-Pinzer. I-Chemistry Cat chemistry. 6, 1526–1530 (2014).
UHull, J. et al. Ukugcinwa kwehydrogen okujikwayo kusetyenziswa i-carbon dioxide kunye nee-catalysts ze-iridium ezitshintshiweyo kwi-aqueous media kumaqondo obushushu aphakathi kunye noxinzelelo. Nat. Chemical. 4, 383–388 (2012).
UWei, D. et al. I-Mn-Pincer complex isetyenziselwa i-hydrogenation eguqukayo ye-carbon dioxide ibe yi-formic acid xa kukho i-lysine. Nat. vitality. 7, 438–447 (2022).
UPiccirilli L., uPinheiro DL kunye noNielsen M. Pincer Inkqubela yakutshanje kwi-transitive metal catalysts zophuhliso oluzinzileyo. catalyst. 10, 773 (2020).
Wei, D., Junge, H. kunye noBeller, M. Iinkqubo ze-amino acid zokubamba i-carbon dioxide kunye nokusetyenziswa kwe-catalytic ukuvelisa i-formate. Isayensi yekhemikhali. 12, 6020–6024 (2021).
I-Subramanian M. et al. Ukudluliselwa kwe-hydrogenation ye-ruthenium ehambelanayo kunye neyodwa, i-deuteration kunye ne-methylation yeekhompawundi ezisebenzayo ezine-methanol. J. Cutler. 425, 386–405 (2023).
UNi Z., uPadilla R., uPramanik R., uJorgensen MSB kunye noNielsen M. Ukudibanisa i-ethanol kwi-ethyl acetate engenasiseko kwaye engenakwamkela kusetyenziswa ii-PNP complexes. I-Dalton's span. 52, 8193–8197 (2023).
UFu, S., uShao, uZ., uWang, uY., kunye noLiu, uQ. I-Manganese-yabangela ukuphuculwa kwe-ethanol ibe yi-1-butanol. J. Am. Bitch. 139, 11941–11948 (2017).