Yɛda mo ase sɛ moakɔ Nature.com. Browser no nkyerɛase a wode redi dwuma no wɔ CSS mmoa kakraa bi. Sɛ wopɛ sɛ wunya nea eye sen biara a, yɛhyɛ nyansa sɛ fa wo browser no foforo di dwuma (anaasɛ gyae Compatibility Mode wɔ Internet Explorer mu). Saa bere yi de, sɛnea ɛbɛyɛ a yɛbɛhwɛ ma wɔakɔ so aboa no, yɛrekyerɛ sait no a yɛmfa styling anaa JavaScript nka ho.
Formic acid yɛ nneɛma a ɛhyɛ bɔ sen biara a wɔde besie hydrogen a ɛyɛ nsu bere tenten no mu biako. Ɛha na yɛde ruthenium clamp complexes foforo a ɛtoatoa so a ɛwɔ general formula [RuHCl(POP)(PPh3)] a wɔde xanthos-type tridentate POP clamp ligands a wotumi tɔ anaasɛ ɛnyɛ den sɛ wɔbɛyɛ no di dwuma no kyerɛ. Yɛde saa nneɛma a ɛyɛ den yi yɛɛ dehydrogenate formic acid de yɛɛ CO2 ne H2 wɔ tebea horow a emu nyɛ den a ɛnyɛ nea ɛsan kɔ mu a yɛde ionic nsu BMIM OAc (1-butyl-3-methylimidazolium acetate) dii dwuma sɛ aduru. Sɛ yɛhwɛ mpɛn dodow a ɛdannan kɛse a, ade a ɛma nneɛma yɛ adwuma yiye sen biara ne [RuHCl(xantphos)(PPh3)]Ru-1 complex a wonim no wɔ nhoma ahorow mu, a ɛwɔ mpɛn dodow a ɛdannan kɛse a ɛyɛ 4525 h-1 wɔ 90 °C mu simma 10. Nsakraeɛ akyi dodoɔ yɛ 74%, na wɔwiee nsakraeɛ no wɔ nnɔnhwereɛ 3 mu (>98%). Ɔkwan foforo so no, catalyst a ɛwɔ adwumayɛ a eye sen biara wɔ ne nyinaa mu, ayɛsɛm [RuHCl(iPr-dbfphos)(PPh3)]Ru-2 complex, hyɛ nsakrae a edi mũ ho nkuran wɔ 1 h mu, na ɛde ne nyinaa mu turnover rate a ɛyɛ 1009 h-1 ba. Bio nso, wohuu catalytic dwumadi nso wɔ ɔhyew a ɛkɔ 60 °C mu. Wɔ gas fã no mu no, CO2 ne H2 nkutoo na wohuu; Wɔanhu CO. High-resolution mass spectrometry kyerɛɛ sɛ N-heterocyclic carbene complexes wɔ reaction mixture no mu.
Ahoɔden a wɔyɛ no foforo gua so kyɛfa a ɛrenya nkɔanim ne nea ɛsakra no ama wɔahwehwɛ mfiridwuma mu ahoɔden a wɔkora so mfiridwuma wɔ tumi, ɔhyew, mfiridwuma ne akwantuo mu1,2. Wobu hydrogen sɛ ahoɔden a ɛdɔɔso sen biara no mu biako3, na nsuo a ɛyɛ nkwaboaa hydrogen a wɔde fa nneɛma (LOHCs) abɛyɛ nhwehwɛmu a wɔde wɔn adwene asi so nnansa yi ara, na ɛde bɔhyɛ ma sɛ wɔbɛkora hydrogen so wɔ ɔkwan a ɛnyɛ den sɛ wɔbɛyɛ ho adwuma a ɔhaw a ɛbata nhyɛsoɔ anaa cryogenic mfiridwuma ho nni mu ,5,6 na ɛwɔ hɔ. Esiane wɔn honam fam nneɛma nti, wobetumi de akwantu nhyehyɛe a ɛwɔ hɔ dedaw a wɔde yɛ pɛtro ne pɛtro afoforo a ɛyɛ nsu no mu dodow no ara adi dwuma de akɔ LOHC7,8. Formic acid (FA) honam fam su ma ɛyɛ ɔkannifoɔ a ɔhyɛ bɔ sɛ wɔbɛkora hydrogen a hydrogen mu duru yɛ 4.4%9,10. Nanso, catalytic nhyehyɛe a wɔatintim a wɔde yɛ formic acid dehydrogenation no taa hwehwɛ sɛ wɔde nnuru a ɛyɛ hyew, nsu anaa formic acid a ɛho tew di dwuma,11,12,13,14 a ebia ɛho behia sɛ wɔde solvent vapor separation techniques te sɛ condensation di dwuma, a ebetumi de ɔhaw aba wɔ adetɔfo dwumadie mu. applications, adesoa foforo. Wobetumi adi ɔhaw yi so denam nnuru a wɔde siw nsu a ɛyɛ hyew a ɛnyɛ hwee te sɛ nsu a ɛyɛ ionic a wɔde bedi dwuma so. Kane no, yɛn adwuma kuw no kyerɛe sɛ ionic nsu butylmethylimidazolium acetate (BMIM OAc) yɛ aduru a ɛfata wɔ saa adeyɛ yi mu denam fixing complex Ru-PNP Ru-MACHO type 15 a wɔtɔn no so 95°C na ɛyɛ hyew. Ɛwom sɛ nhyehyɛe ahorow bi adi kan anya TON a ɛkɔ soro de, nanso pii de wɔn ho ato nneɛma a wɔde yɛ nneɛma a ɛyɛ hyew (te sɛ THF anaa DMF) anaa nneɛma a wɔde ka ho a wɔde di dwuma (te sɛ nnyinaso) so. Nea ɛne eyi bɔ abira no, yɛn adwuma no de nsu a ɛnyɛ nea ɛyɛ hyew (ILs) na edi dwuma ankasa na wɔmfa nneɛma a wɔde ka ho nni dwuma.
Hazari ne Bernskoetter bɔɔ amanneɛ sɛ wɔde Fe-PNP catalyst a ɛwɔ dioxane ne LiBF4 anim no de hydrogenation a ɛwɔ formic acid (FA) mu wɔ 80 °C mu, na ɛmaa turnover dodow (TON) a ɛyɛ nwonwa a ɛyɛ bɛyɛ 1,000,00016. Laurenci de Ru(II)- complex catalyst TPPPTS dii dwuma wɔ FA dehydrogenation nhyehyɛe a ɛkɔ so mu. Saa kwan yi maa ɛkame ayɛ sɛ FA dehydrogenation a edi mũ a wohuu CO kakraa bi pɛ wɔ 80 °C17. Sɛnea ɛbɛyɛ a ɛbɛma saa afuw yi anya nkɔso kɛse no, Pidko kyerɛɛ FA a wotumi dannan no dehydrogenation a wɔde Ru-PNP clamp catalysts a ɛwɔ DMF/DBU ne DMF/NHex3 afrafra mu dii dwuma, na onyaa TON bo a ɛyɛ 310,000 kosi 706,500 wɔ 90 °C18 mu. Hull, Himeda ne Fujita suaa binuclear Ir complex catalyst a wɔde KHCO3 ne H2SO4 bɔɔ afɔre wom, na wɔsesa CO2 hydrogenation ne FA dehydrogenation. Wɔn nhyehyɛe no nyaa TON a ɛboro 3,500,000 ne 308,000 maa hydrogenation wɔ 30°C, CO2/H2 (1:1), 1 bar nhyɛso ne dehydrogenation a ɛwɔ 60 ne 90°C19 ntam. Sponholz, Junge ne Beller yɛɛ Mn-PNP complex a wɔde bɛdan CO2 hydrogenation ne FA dehydrogenation wɔ 90 °C20.
Ɛha yi yɛde IL kwan dii dwuma, nanso sɛ́ anka yɛde Ru-PNPs bedi dwuma no, yɛhwehwɛɛ Ru-POP catalysts a wɔde di dwuma mu, a sɛnea yenim no, wonnya nkyerɛɛ bi da wɔ eyi mu.
Esiane wɔn dade-ligand coupling (MLC) a eye kyɛn so nti, amino-PNP clamp complexes a egyina Noyori-su nsusuwii so a ɛne amino dwumadi akuw a ɛto so abien 21 (te sɛ Ru-MACHO-BH) a ɛne wɔn ho wɔn ho di nkitaho no reyɛ nea agye din kɛse wɔ molecule nketewa dwumadi ahorow bi mu. Nhwɛsoɔ a agye din ne CO22, hydrogenation a ɛwɔ alkenes ne carbonyls mu, transfer hydrogenation23 ne acceptorless dehydrogenation a ɛwɔ alcohols mu24. Wɔabɔ amanneɛ sɛ N-methylation a ɛwɔ PNP clamp ligands mu no betumi agyae catalyst dwumadi no koraa25, a wobetumi akyerɛkyerɛ mu denam nokwasɛm a ɛyɛ sɛ amines yɛ proton fibea, a ɛyɛ ahwehwɛde a ɛho hia wɔ catalytic cycle a wɔde MLC di dwuma no mu. Nanso, nnansa yi ara Beller huu su a ɛne no bɔ abira wɔ formic acid dehydrogenation mu, faako a N-methylated Ru-PNP complexes daa catalytic dehydrogenation a ɛyɛ papa adi ankasa wɔ formic acid mu sen wɔn mfɛfo a wɔmfa methylated no Esiane sɛ kan complex no ntumi mfa amino unit no so nnya kyɛfa wɔ MLC mu nti, eyi kyerɛ denneennen sɛ MLC, na ɛno nti amino unit no, betumi adi dwuma a ɛho nhia pii wɔ (de)hydrogenation nsakrae ahorow bi mu sen sɛnea na wosusuw kan no.
Sɛ wɔde toto POP clamps ho a, wɔansua ruthenium complexes a ɛwɔ POP clamps mu no ho ade yiye wɔ saa beae yi. Wɔde POP ligands adi dwuma wɔ atetesɛm mu titiriw ama hydroformylation, baabi a wɔyɛ adwuma sɛ chelating ligands sen sɛ ɛbɛyɛ bidentate bite angle a ɛyɛ su a ɛyɛ bɛyɛ 120° ama clamping ligands, a wɔde adi dwuma de ayɛ selectivity yiye ama linear ne branched products27,28,29. Efi saa bere no, wɔntaa mfa Ru-POP complexes nni dwuma wɔ hydrogenation catalysis mu, nanso wɔadi kan abɔ wɔn dwumadi ho nhwɛso ahorow wɔ transfer hydrogenation mu ho amanneɛ30. Ɛha na yɛkyerɛ sɛ Ru-POP complex no yɛ catalyst a etu mpɔn ma dehydrogenation of formic acid, si so dua sɛ Beller hui sɛ amino unit a ɛwɔ classical Ru-PNP amine catalyst no mu no ho nhia pii wɔ saa adeyɛ yi mu.
Yɛn adesua no fi ase denam catalysts abien a wɔtaa yɛ a ɛwɔ general formula [RuHCl(POP)(PPh3)] (Mfonini 1a) a wɔyɛ no so. Sɛnea ɛbɛyɛ a wɔbɛsesa steric ne electronic nhyehyɛe no, wɔpaw dibenzo[b,d]furan fii 4,6-bis(diisopropylphosphino) a wɔtɔn no mu (Mfonini 1b) 31. Wɔde ɔkwan a Whittlesey32 yɛe wɔ ɔkwan a ɛkɔ akyiri so na ɛyɛɛ catalysts a wɔasua ho ade wɔ adwuma yi mu, a wɔde [RuHCl(PPh3)3]•toluene33 adduct dii dwuma sɛ nea edi kan. Fa dade precursor ne POP clamp ligand fra THF mu wɔ tebea horow a nsu nnim na mframa nnim koraa mu. Wɔde kɔla a ɛsakra kɛse fi kɔkɔɔ tuntum kɔɔ kɔkɔɔ kaa adeyɛ no ho na ɛmaa ade a ɛho tew bere a wɔde nnɔnhwerew 4 asan akɔ akyi anaasɛ nnɔnhwerew 72 a wɔde asan akɔ akyi wɔ 40°C akyi. Bere a woyii THF no wɔ vacuum mu na wɔde hexane anaa diethyl ether hohoroo ho mprenu akyi no, woyii triphenylphosphine no fii mu ma wonyaa ade no sɛ powder kɔkɔɔ a ɛwɔ aba dodow a ɛkɔ soro.
Ru-1 ne Ru-2 a ɛyɛ den a wɔyɛ. a) Ɔkwan a wɔfa so yɛ nneɛma a ɛyɛ den. b) Nhyehyeɛ a ɛwɔ synthesized complex no mu.
Wonim Ru-1 dedaw fi nhoma ahorow mu32, na su foforo twe adwene si Ru-2 so. 1H NMR spectrum a ɛwɔ Ru-2 no sii cis nhyehyɛe a ɛwɔ phosphine atom a ɛwɔ ligand a ɛwɔ hydride baanu no mu no so dua. Peak dt plot (Mfonini 2a) kyerɛ 2JP-H coupling constants a ɛyɛ 28.6 ne 22.0 Hz, a ɛwɔ amanneɛbɔ a atwam a wɔhwɛ kwan no mu32. Wɔ hydrogen decoupled 31P {1H} spectrum (Mfonini 2b) mu no, wohuu 2JP-P coupling constant a ɛbɛyɛ 27.6 Hz, a ɛkyerɛ sɛ clamp ligand phosphines ne PPh3 nyinaa yɛ cis-cis. Bio nso, ATR-IR kyerɛ ruthenium-hydrogen trɛw a ɛda nsow wɔ 2054 cm-1. Sɛnea ɛbɛyɛ a structural elucidation foforo, Ru-2 complex no crystallized denam vapor diffusion wɔ dan mu hyew a ne su a ɛdɔɔso ma X-ray adesua (Fig. 3, Supplementary Table 1). Ɛyɛ ahwehwɛ wɔ triclinic nhyehyɛe a ɛwɔ ahunmu kuw P-1 mu a cocrystalline benzene unit biako wɔ unit cell biara mu. Ɛda P-Ru-P occlusal angle a ɛtrɛw a ɛyɛ 153.94° adi, a ɛtrɛw kɛse sen 130° occlusal angle a ɛwɔ bidentate DBFphos34 no. Wɔ 2.401 ne 2.382 Å no, Ru-PPOP nkitahodi tenten no ware kɛse sen Ru to PPh3 nkitahodi tenten a ɛyɛ 2.232 Å, a ebia efi DBFphos akyi dompe a ɛtrɛw a ɛyɛ adidibea a ɛyɛ mmerɛw a ne mfinimfini 5-ring no de ba no. Geometry a ɛwɔ dadeɛ mfimfini no yɛ octahedral titire a O-Ru-PPh3 anim yɛ 179.5°. H-Ru-Cl nkitahodi no nyɛ linear koraa, na ɛwɔ anim bɛyɛ 175° fi triphenylphosphine ligand no so. Wɔabobɔ atom akwansin ne bond tenten wɔ Table 1 mu.
NMR spectrum a ɛwɔ Ru-2 mu. a) Hydride mpɔtam a ɛwɔ 1H NMR spectrum no mu a ɛkyerɛ Ru-H dt sɛnkyerɛnne. b) 31 P{ 1 H} NMR spectrum a ɛkyerɛ nsɛnkyerɛnne a efi triphenylphosphine (blue) ne POP ligand (green) mu.
Ru-2 no nhyehyɛe. Wɔda ɔhyew ellipsoids adi a ɛyɛ 70% a ɛbɛtumi aba. Nea ɛbɛyɛ na emu ada hɔ no, wɔayi cocrystalline benzene ne hydrogen atom a ɛwɔ carbon no so no afi mu.
Sɛnea ɛbɛyɛ a wɔbɛhwɛ tumi a complexes no tumi dehydrogenate formic acid no, wɔpaw reaction tebea horow a PNP-clamp complexes a ɛne no hyia (sɛ nhwɛso no, Ru-MACHO-BH) no yɛ adwuma kɛse15. Dehydrogenation a 0.5 ml (13.25 mmol) formic acid de 0.1 mol% (1000 ppm, 13 μmol) ruthenium complex Ru-1 anaa Ru-2 a wɔde 1.0 ml (5.35 mmol) ionic nsu (IL) BMIM OAc (pon-mfonini) 2; Mfonini 4);
Sɛnea ɛbɛyɛ na wɔanya gyinapɛn no, wodii kan yɛɛ adeyɛ no denam precursor adduct [RuHCl(PPh3)3]·toluene so. Wɔyɛ adeyɛ no wɔ ɔhyew a efi 60 kosi 90 °C mu. Sɛnea nneɛma a wɔde aniwa hu a ɛnyɛ den kyerɛ no, wɔantumi annye aduru a ɛyɛ den no koraa wɔ IL mu mpo sɛ wɔkanyan no bere tenten wɔ ɔhyew a ɛyɛ 90°C mu, nanso ɛpopetee bere a wɔde formic acid baa mu akyi. Wɔ 90°C mu no, wɔnyaa nsakraeɛ 56% (TOF = 3424 h-1) wɔ simma 10 a ɛdi kan no mu, na ɛkame ayɛ sɛ wɔnya nsakraeɛ dodoɔ (97%) wɔ nnɔnhwereɛ mmiɛnsa akyi (ɛhyɛn mu 1). Sɛ wɔtew ɔhyew no so kɔ 80 °C a, ɛtew nsakrae no so bɛboro fã kosi 24% wɔ simma 10 akyi (TOF = 1467 h-1, nsɛm a wɔde hyɛ mu 2), na ɛsan tew so kɔ 18% ne 18% wɔ 70 °C ne 60 °C, sɛnea ɛte biara 6% (nkyerɛwee 3 ne 4). Wɔ nsɛm no nyinaa mu no, wɔanhu induction bere biara, a ɛkyerɛ sɛ ebia catalyst no yɛ reactive species anaasɛ reactive species no nsakrae yɛ ntɛmntɛm dodo sɛ wobetumi de saa data set yi ahu.
Wɔ precursor nhwehwɛmu akyi no, wɔde Ru-POP clamp complexes Ru-1 ne Ru-2 dii dwuma wɔ tebea koro no ara mu. Wɔ 90°C mu no, wohuu nsakrae kɛse ntɛm ara. Ru-1 nyaa nsakraeɛ 74% wɔ simma 10 a ɛdi kan wɔ sɔhwɛ no mu (TOFmax = 4525 h-1, entry 5). Ru-2 daa dwumadie a ɛsua kakra nanso ɛkɔ so daa adi, na ɛhyɛɛ nsakraeɛ 60% ho nkuran wɔ simma 10 mu (TOFmax = 3669 h-1) ne nsakraeɛ a ɛdi mũ wɔ simma 60 mu (>99%) (ɛhyɛn mu 9). Ɛsɛ sɛ yɛhyɛ no nsow sɛ Ru-2 korɔn kɛse sen dade a edi kan no ne Ru-1 wɔ nsakrae a edi mũ mu. Enti, bere a dade a edi kan ne Ru-1 wɔ TOFoverall gyinapɛn a ɛte saa ara wɔ adeyɛ a wɔawie (330 h-1 ne 333 h-1, sɛnea ɛte biara) no, Ru-2 wɔ TOFoverall a ɛyɛ 1009 h-1.
Afei wɔde Ru-1 ne Ru-2 yɛɛ ɔhyew nsakrae a ɛmaa ɔhyew no so tew nkakrankakra wɔ 10 °C nkɔanim mu koduu anyɛ yiye koraa no 60 °C (Mfonini 3). Sɛ wɔ 90°C no, complex no daa dwumadi adi ntɛm ara a, ɛkame ayɛ sɛ nsakrae koraa ba wɔ dɔnhwerew biako mu, ɛnde wɔ ɔhyew a ɛba fam mu no dwumadi no so tew kɛse. Py-1 nsakraeɛ no yɛ 14% ne 23% wɔ simma 10 akyi wɔ 80°C ne 70°C, na simma 30 akyi no ɛkɔɔ soro koduu 79% ne 73% (nkyerɛwee 6 ne 7). Nsɔhwɛ abien no nyinaa kyerɛe sɛ nsakrae dodow yɛ ≥90% wɔ nnɔnhwerew abien mu. Wohuu suban a ɛte saa ara wɔ Ru-2 ho (nkyerɛwee 10 ne 11). Nea ɛyɛ anigye no, Ru-1 dii tumi kakra wɔ adeyɛ no awiei wɔ 70 °C a TOF nyinaa yɛ 315 h-1 sɛ wɔde toto 292 h-1 ma Ru-2 ne 299 h-1 ma dade a edi kan no ho a.
Ɔhyew a ɛso tewee bio koduu 60 °C no ma wohuu nsakrae biara wɔ simma 30 a edi kan wɔ sɔhwɛ no mu. Na Ru-1 nyɛ adwuma kɛse wɔ ɔhyew a ɛba fam koraa mu wɔ sɔhwɛ no mfiase na akyiri yi ɛmaa dwumadi kɔɔ soro, a ɛkyerɛ sɛ ɛho hia sɛ wɔyɛ adwuma bere a wɔdan Ru-1 precatalyst no ma ɛbɛyɛ catalytically active species. Ɛwom sɛ eyi betumi aba wɔ ɔhyew nyinaa mu de, nanso simma 10 a wɔde dii sɔhwɛ no mfiase no nnɔɔso sɛ wobehu bere a wɔde yɛ adwuma wɔ ɔhyew a ɛkorɔn mu. Wohuu suban a ɛte saa ara wɔ Ru-2 ho. Wɔ 70 ne 60 °C mu no, wɔanhu nsakrae biara wɔ simma 10 a edi kan wɔ sɔhwɛ no mu. Ɛho hia sɛ yɛhyɛ no nsow sɛ wɔ nhwehwɛmu abien no nyinaa mu no, wɔanhu carbon monoxide a ɛba wɔ yɛn adwinnade no anohyeto a wɔde hu (<300 ppm) no mu, a H2 ne CO2 nkutoo ne nneɛma a wohuu.
Ntotoeɛ a ɛfa formic acid dehydrogenation aba a wɔdii kan nyaeɛ wɔ saa adwumakuo yi mu, a ɛyɛ adwini tebea ananmusifoɔ na wɔde Ru-PNP clamp complexes di dwuma, kyerɛɛ sɛ Ru-POP clamp a wɔayɛ no foforɔ no wɔ dwumadie a ɛte sɛ ne PNP yɔnko 15. Bere a clamp PNP no nyaa RPMs a ɛyɛ 500-1260 h-1 wɔ batch nhwehwɛmu mu no, POP clamp foforɔ no nyaa TOFovertal boɔ a ɛte saa ara a ɛyɛ 326 h-1, na wohuu TOFmax gyinapɛn ahorow a ɛwɔ Ru-1 ne 1590 h-1 mu. sɛnea ɛte biara no, yɛ 1988 h-1 ne 1590 h-1. Ru-2 yɛ 1 wɔ 80 °C, Ru-1 yɛ 4525 h-1 na Ru-1 yɛ 3669 h-1 wɔ 90 °C, sɛnea ɛte biara.
Ɔhyew a wɔde hwehwɛ formic acid dehydrogenation a wɔde Ru-1 ne Ru-2 catalysts di dwuma. Tebea horow: 13 μmol ade a ɛma nneɛma yɛ kɛse, 0.5 ml (13.25 mmol) formic acid, 1.0 ml (5.35 mmol) BMIM OAc.
Wɔde NMR di dwuma de te akwan horow a wɔfa so yɛ ade no ase. Esiane sɛ nsonsonoe kɛse wɔ 2JH-P mu wɔ hydride ne phosphine ligand ntam nti, nhwehwɛmu yi adwene si hydride peak no so. Wɔ Ru-1 fam no, wohuu dt nhyehyɛe a ɛtaa ba wɔ hydrogenation unit no mu wɔ simma 60 a edi kan a wɔde dehydrogenation yɛɛ no ​​mu. Ɛwom sɛ nsakraeɛ kɛseɛ bi wɔ fam fi −16.29 kɔsi −13.35 ppm deɛ, nanso ne coupling constants ne phosphine yɛ 27.2 ne 18.4 Hz, sɛdeɛ ɛteɛ biara (Mfonini 5, Peak A). Eyi ne phosphine abiɛsa a hydrogen ligand no wɔ cis nhyehyɛe no mu no nyinaa hyia na ɛkyerɛ sɛ ligand nhyehyɛe no gyina hɔ pintinn kakra wɔ IL no mu bɛyɛ dɔnhwerew biako wɔ tebea horow a ɛyɛ papa mu. Ebia nsakrae a emu yɛ den a ɛba fam no fi chlorinated ligands a wɔayi afi hɔ ne acetyl-formic acid complexes a ɛne no hyia a ɛba, d3-MeCN complex a ɛba wɔ situ mu wɔ NMR tube no mu, anaasɛ N-heterocycles a ɛne no hyia a ɛbae. kyerɛkyerɛɛ mu. Carbene (NHC) a ɛyɛ den. Wɔ dehydrogenation reaction no mu no, saa sɛnkyerɛnne yi mu den kɔɔ so so tew, na simma 180 akyi no, wɔanhu sɛnkyerɛnne no bio. Mmom no, wohuu nsɛnkyerɛnne foforo abien. Nea edi kan no kyerɛ dd nhyehyɛe a emu da hɔ a ɛba wɔ -6.4 ppm (peak B). Doublet no wɔ coupling constant kɛseɛ a ɛyɛ bɛyɛ 130.4 Hz, a ɛkyerɛ sɛ phosphine units no mu baako akɔ baabiara sɛ wɔde toto hydrogen no ho a. Eyi betumi akyerɛ sɛ wɔsan hyehyɛ POP krampɔn no ma ɛyɛ κ2-P,P nhyehyɛe. Ebia sɛnea saa ade a ɛyɛ den yi puei wɔ catalysis awiei no bɛkyerɛ sɛ saa ɔkwan yi de akwan a wɔfa so deactivation ba bere tenten mu, na ɛyɛ catalyst sink. Ɔkwan foforɔ so no, nnuru a ɛsakra a ɛba fam no kyerɛ sɛ ebia ɛyɛ dihydrogenous species15. Peak foforo a ɛto so abien no wɔ -17.5 ppm. Ɛwom sɛ wonnim ne mpopaho de, nanso yegye di sɛ ɛyɛ abiɛsa a ɛwɔ coupling constant ketewaa bi a ɛyɛ 17.3 Hz, a ɛkyerɛ sɛ hydrogen ligand no kyekyere phosphine ligand a ɛwɔ POP clamp no mu nkutoo, na ɛkyerɛ nso sɛ triphenylphosphine (peak C) no fi adi. Wobetumi de ligand foforo asi ananmu, te sɛ acetyl kuw anaa NHC a wɔayɛ wɔ beae a efi ionic nsu no mu. PPh3 a ɛpaapae no, wɔsan kyerɛ denam singlet a emu yɛ den a ɛwɔ -5.9 ppm so. wɔ 31P{1H} spectrum a ɛwɔ Ru-1 mu wɔ simma 180 akyi wɔ 90 °C (hwɛ nsɛm foforo).
Hydride mpɔtam a ɛwɔ 1H NMR spectrum a ɛwɔ Ru-1 mu bere a wɔreyɛ dehydrogenation a ɛwɔ formic acid mu no. Tebea ahorow a ɛma ɛyɛ adwuma: 0.5 ml formic acid, 1.0 ml BMIM OAc, 13.0 μmol catalyst, 90 °C. Wɔfaa NMR fii MeCN-d 3 , 500 μl a wɔde deuterated solvent, bɛyɛ 10 μl a ɛyɛ reaction mixture no mu.
Sɛnea ɛbɛyɛ a wɔbɛkɔ so asi so dua sɛ mmoa ahorow a wɔyɛ nnam wɔ catalytic nhyehyɛe no mu no, wɔyɛɛ Ru-1 nhwehwɛmu a ɛyɛ high resolution mass spectrometry (HRMS) bere a wɔde formic acid ahyɛ mu simma 10 wɔ 90 °C akyi. Eyi kyerɛ sɛ mmoa ahorow a wonni chlorine ligand precatalyst no wɔ afrafrade a wɔde yɛ ade no mu. ne NHC complexes mmienu nso, a wɔakyerɛ sɛ ɛyɛ ne nhyehyɛeɛ wɔ Mfonini 6. Yebetumi ahunu HRMS spectrum a ɛne no hyia no wɔ Supplementary Figure 7.
Yegyina saa nsɛm yi so de intrasphere reaction mechanism a ɛte sɛ nea Beller de too gua no ho nyansahyɛ ma, a N-methylated PNP clamps catalyze adeyɛ koro no ara. Nsɔhwɛ afoforo a wɔamfa ionic nsu anhyɛ mu no ankyerɛ dwumadi biara, enti ɛte sɛ nea ɛho hia sɛ ɛde ne ho hyɛ mu tẽẽ. Yɛfa no sɛ Ru-1 ne Ru-2 a wɔma ɛyɛ adwuma no nam chloride a wɔpaapae mu a ɛno akyi no, NHC a ebetumi aba sɛ wɔde bɛka ho ne triphenylphosphine a wɔpaapae (Scheme 1a). Wɔde HRMS adi kan ahu saa dwumadie yi wɔ mmoa ahodoɔ nyinaa mu. IL-acetate yɛ Bronsted base a ɛyɛ den sen formic acid na ɛtumi deprotonate nea ɛtwa toɔ no mu den35. Yɛfa no sɛ wɔ catalytic cycle (Scheme 1b) mu no, active species A a ɛwɔ NHC anaa PPh3 no nam formate so yɛ biako ma ɛyɛ species B. Reconfiguration of this complex to C awiei koraa no ɛde CO2 ne trans-dihydrogen complex D no gyae Protonation a edi hɔ a acid no yɛ dihydro complex a ɛne acetic acid a wɔadi kan ayɛ no yɛ dihydro complex E ne te sɛ anammɔn titiriw a Beller de N-methylated PNP clamp homologues dii dwuma de too gua no. Bio nso, na wɔadi kan ayɛ EL = PPh3 a ɛyɛ den no analogue denam stoichiometric reaction a wɔde Ru-1 di dwuma wɔ hydrogen wim bere a wɔde sodium nkyene ayi chloride akyi no so. Hydrogen a woyi fi hɔ ne formate a ɛyɛ biako no ma wonya A na ɛma kyinhyia no wie.
Wɔahyɛ ɔkwan bi a wɔfa so yɛ intrasphere reaction a formic acid dehydrogenation a wɔde fixing complex Ru-POP Ru-1 di dwuma no ho nyansa.
Wɔayɛ ade foforo a ɛyɛ den [RuHCl(iPr-dbfphos)(PPh3)]. Wɔde NMR, ATRIR, EA ne X-ray diffraction nhwehwɛmu a wɔyɛe wɔ ahwehwɛ biako mu na ɛkyerɛɛ complex no. Yɛsan nso bɔ amanneɛ sɛ wɔde Ru-POP pincer complexes dii dwuma nea edi kan a edii nkonim wɔ dehydrogenation a ɛwɔ formic acid mu kɔ CO2 ne H2 mu. Ɛwom sɛ dade a edi kan no nyaa dwumadi a ɛte saa ara (ɛkɔ 3424 h-1) de, nanso complex no duu mpɛn dodow a ɛdannan kɛse a ɛkɔ 4525 h-1 wɔ 90 °C. Afei nso, wɔ 90 °C mu no, complex foforo [RuHCl(iPr-dbfphos)(PPh3)] no nyaa bere a ɛde tu nyinaa (1009 h-1) de wiee formic acid dehydrogenation, a ɛkorɔn kɛse sen nea ɛwɔ dade a edi kan no mu (330 h-1). ne nea wɔadi kan abɔ ho amanneɛ a ɛyɛ den [RuHCl(xantphos)(PPh3)] (333 h-1). Wɔ tebea horow a ɛte saa ara mu no, catalytic efficiency no yɛ nea wotumi de toto Ru-PNP clamp complex no ho. HRMS data kyerɛ sɛ carbene complex bi wɔ reaction mixture no mu, ɛwom sɛ ɛyɛ kakraa bi de. Mprempren yɛresua sɛnea carbene complexes tumi yɛ ade a ɛma nneɛma yɛ kɛse no ho ade.
Wɔde nsɛm a wonyae anaa wɔhwehwɛɛ mu wɔ nhwehwɛmu yi mu nyinaa ka asɛm a wɔatintim yi ho [ne nsɛm fael ahorow a ɛfoa so].
Azarpour A., ​​Suhaimi S., Zahedi G. ne Bahadori A. Nhwehwɛmu a wɔyɛe wɔ sintɔ ahorow a ɛwɔ ahoɔden a wɔyɛ no foforo mu sɛ daakye ahoɔden fibea a ɛhyɛ bɔ. Arabfoɔ. J. Nyansahu. engyinia. 38, 317–328 (2013) Nsɛm a wɔahyehyɛ.
Moriarty P. ne Honery D. Dɛn ne wiase nyinaa tumi a ɛwɔ ahoɔden a wɔyɛ no foforo? sakra mu. mmoa. Ahoɔden Nkyerɛkyerɛmu 16, 244-252 (2012).
Rao, PC ne Yoon, M. Nsuo organic hydrogen soafoɔ (Lohc) nhyehyɛeɛ a ɛbɛtumi aba: nkɔsoɔ a aba nnansa yi mu nhwehwɛmu. Ahoɔden 13, 6040 (2020).
Niermann, M., Beckendorf, A., Kaltschmitt, M. ne Bohnhoff, K. Nsuo mu hydrogen a wɔde fa nneɛma (LOHC) – nhwehwɛmu a egyina nnuru ne sikasɛm mu nneɛma so. amanaman ntam nkitahodi. J. Hydrogen ahoɔden. 44, 6631–6654 (2019) Nsɛm a wɔahyehyɛ.
Teichmann, D., Arlt, W., Wasserscheid, P. ne Freimann, R. Daakye ahoɔden fibea a egyina nsuo a ɛwɔ hydrogen a wɔde fa nsuo mu (LOHC) so. ahoɔden a atwa yɛn ho ahyia. saense. 4, 2767–2773 (2011) Nsɛm a wɔahyehyɛ.
Niermann, M., Timmerberg, S., Drunert, S. ne Kaltschmitt, M. Nsu a wɔde fa hydrogen a ɛwɔ nkwa mu ne akwan foforo a wɔfa so de hydrogen a wɔyɛ no foforo kɔ amanaman ntam. sakra mu. mmoa. Ahoɔden Ed. 135, 110171 (2021) na ɔkyerɛwee.
Rong Y. ne afoforo. Amanaman ntam mfiridwuma ne sikasɛm mu nhwehwɛmu a ɛfa hydrogen a wɔkora so ne nea wɔde fi hydrogen adwumayɛbea kɔ hydrogenation terminal station. J. Hydrogen ahoɔden. 1–12 10.1016/j.ijhydene.2023.01.187 (2023) Ɔkwan a wɔfa so yɛ aduru a ɛma obi nya apɔwmuden.
Guo, J. ne afoforo. Formic acid sɛ ɔkwan a ebetumi aba sɛ wɔkora hydrogen so wɔ hyɛn no mu: nkɔso a ɛyɛ pɛ a ɛyɛ dade a ɛyɛ anuonyam a ɛma dehydrogenation reactions. Seuss Nnuruyɛ Ho Adesua. 14, 2655–2681 (2021) Nsɛm a wɔahyehyɛ.
Muller, K., Brooks, K., ne Autry, T. Hydrogen a wɔkora so wɔ formic acid mu: ntotoho a ɛfa akwan horow a wɔfa so yɛ adwuma ho. Ahoɔden a wɔde yɛ pɛtro. 31, 12603–12611 (2017) Nsɛm a wɔahyehyɛ.
Wang, Z., Lu, SM, Li, J., Wang, J. ne Li, Q. Iridium a ɛyɛ den a N,N’-diimine ligand wom no wɔ formic acid dehydrogenation dwumadi a ɛkorɔn a ebi mmae da wɔ nsu mu. Nnuru a wɔde yɛ nneɛma. – EURO – Ɔde ne nsa kyerɛɛ ne so. J. 21, 12592-12595 (2015) Ɔkwan a wɔfa so yɛ aduru.
Hong D. ne afoforo. Synergistic nkɛntɛnso a heterobinuclear IrIII-MII complexes nya wɔ catalytic release of H2 bere a dehydrogenation formic acid wɔ nsu mu. Nneɛma a nkwa nnim. Nnuru a wɔde yɛ nneɛma. 59, 11976–11985 (2020) Ɔde ne nsa kyerɛɛ ne so.
Fink K., Laurenci GA ne ade a ɛsom bo a ɛma rhodium-catalyzed dehydrogenation a ɛwɔ formic acid mu wɔ nsu mu. EURO. J.Inorg na ɔkyerɛwee. Nnuru a wɔde yɛ nneɛma. 2381–2387 (2019) na ɔkyerɛwee.
Seraj, JJA, ne afoforo. Ade a etu mpɔn a ɛma formic acid a ɛho tew no dehydrogenation yɛ adwuma. Nat. nkutahodie. 7, 11308 (2016) na ɔkyerɛwee.
Piccirelli L. ne afoforo. Multifunctional catalysis a CO2 hydrogenation-dehydrogenation de Ru-PNP / ionic nsu nhyehyɛe. J. Am. Bitch a ɔyɛ ɔbarima. 145, 5655–5663 (2023) Nsɛm a wɔahyehyɛ.
Belinsky E. A. ne afoforo. Dehydrogenation a formic acid ne Lewis acid de dade catalyst a ɛwɔ Pinzer support so. J. Am. Bitch a ɔyɛ ɔbarima. 136, 10234-10237 (2014) Nsɛm a wɔahyehyɛ.
Henriks V., Juranov I., Autissier N. ne Laurenci G. Dehydrogenation a formic acid wɔ homogeneous Ru-TPPTS catalysts: CO a wɔmpɛ ne nea woyi fi hɔ yiye denam PROX so. ade a ɛma nneɛma yɛ kɛse. 7, 348 (2017) na ɔkyerɛwee.
Filonenko GA etc. Hydrogenation a etu mpɔn na wotumi dannan carbon dioxide mu kɔ formate mu denam ruthenium catalyst PNP-Pinzer a wɔde di dwuma so. Nnuruyɛ Cat chemistry. 6, 1526–1530 (2014) Ɔde ne nsa kyerɛɛ ne so.
Hull, J. ne afoforo. Hydrogen a wɔtumi dane a wɔde carbon dioxide ne proton-switched iridium catalysts di dwuma wɔ nsuo mu wɔ ɔhyew ne nhyɛsoɔ a ɛkɔ fam mu. Nat. Nnuru a wɔde yɛ nneɛma. 4, 383–388 (2012) Nsɛm a wɔahyehyɛ.
Wei, D. ne afoforo. Wɔde Mn-Pincer complex no di dwuma ma hydrogenation a wotumi dannan carbon dioxide ma ɛyɛ formic acid wɔ lysine anim. Nat. ahoɔden a ɛma obi nya ahoɔden. 7, 438–447 (2022) Nsɛm a wɔahyehyɛ.
Piccirilli L., Pinheiro DL ne Nielsen M. Pincer Nnansa yi nkɔso a aba wɔ nsakrae dade a ɛma nkɔso a ɛtra hɔ daa mu. ade a ɛma nneɛma yɛ kɛse. 10, 773 (2020) na ɔkyerɛwee.
Wei, D., Junge, H. ne Beller, M. Amino acid nhyehyɛe a wɔde kyere carbon dioxide na wɔde di dwuma wɔ catalytic mu de yɛ formate. Nnuru a wɔde yɛ nneɛma. saense. 12, 6020–6024 (2021) Nsɛm a wɔahyehyɛ.
Subramanian M. ne afoforo. General ne selective homogeneous ruthenium transfer hydrogenation, deuteration ne methylation a ɛyɛ adwuma nnuru ne methanol. J. Cutler na ɔkyerɛwee. 425, 386–405 (2023) Nsɛm a wɔahyehyɛ.
Ni Z., Padilla R., Pramanik R., Jorgensen MSB ne Nielsen M. Base-free ne acceptor-free dehydrogenating coupling a ethanol ne ethyl acetate de PNP complexes di dwuma. Dalton a ɔyɛ span no. 52, 8193–8197 (2023) Nsɛm a wɔahyehyɛ.
Fu, S., Shao, Z., Wang, Y., ne Liu, Q. Manganese-catalyzed a ɛma ethanol kɔ soro ma ɛbɛyɛ 1-butanol. J. Am. Bitch a ɔyɛ ɔbarima. 139, 11941–11948 (2017) Ɔde ne nsa kyerɛɛ ne so.