The Department of Chemistry, Brown University, Providence, RI The Department of Chemistry, Yale University, New Haven, CT 06520

Transcription

1 Eletroni Supplementry Mteril (ESI) for Chemil Siene. This journl is The Royl Soiety of Chemistry 2015 Supporting Informtion: Iron Ctlyzed CO 2 Hydrogention to Formte Enhned y Lewis Aid Co-Ctlysts Yunyun Zhng, Alex D. MIntosh, Jnie L. Wong, Elizeth A. Bielinski, Pul G. Willird, Brndon Q. Merdo, Nily Hzri, * nd Wesley H. Bernskoetter, * The Deprtment of Chemistry, Brown University, Providene, RI The Deprtment of Chemistry, Yle University, New Hven, CT e-mil: nily.hzri@yle.edu; w36@rown.edu Tle of Contents: Generl Experimentl Methods nd Chrterizing Dt Tles of Bse Sreening nd Lewis Aid Loding Experimentl Desriptions nd NMR Spetrl Dt X-ry Crystllogrphy Referenes S2 S8 S9 S22 S25 S1

2 Generl Experimentl Methods nd Chrterizing Dt Generl Considertions. All mnipultions were rried out using stndrd vuum, Shlenk, nnul, or gloveox tehniques. Hydrogen nd ron dioxide were purhsed from Corp Brothers nd used s reeived. Compounds 1, 1, HCO 2-1 nd 2 were prepred ording to literture proedures. 1 Compounds ( ipr PN Me P)Fe(H)BH 4, 3 nd 4 were prepred in mnner similr to tht desried y Beller nd oworkers, ut with the slight modifitions desried elow. The lignd MeN{CH 2 CH 2 (PCy 2 )} 2 ws lso prepred y nlogy to previous report, only sustituting LiPCy 2 for LiP i Pr 2. 1,1 All other hemils were purhsed from Aldrih, Fisher, VWR, Strem, or Cmridge Isotope Lortories. Non-voltile solids, surely inluding Cs 2 CO 3, were dried under vuum t 50 C overnight. 1,8-diziylounde-7-ene (DBU) ws dried over CH 2 nd distilled prior to use. Solvents were dried nd deoxygented using literture proedures. 2 1 H, 13 C nd 31 P NMR spetr were reorded on Bruker DRX 400 MHz, Avne 300 nd 600 MHz spetrometers t mient temperture, unless otherwise noted. 1 H nd 13 C hemil shifts re referened to residul solvent signls; 31 P nd 7 Li hemil shifts re referened to the externl stndrds of H 3 PO 4 nd LiCl, respetively. Proe tempertures were lirted using ethylene glyol nd methnol s previously desried. 3 It should e noted tht some NMR experiments employed J. Young NMR tue with up to 3 tm of totl pressure nd pproprite sfety preutions need to e pplied if reproduing these experiments. IR spetr were reorded on Jso 4100 FTIR nd Mettler Toledo Ret IR spetrometers. X-ry rystllogrphi dt were olleted on Bruker D8 QUEST diffrtometer. Smples were olleted in inert oil nd quikly trnsferred to old gs strem. The strutures were solved from diret methods nd Fourier syntheses nd refined y full-mtrix lest-squres proedures with nisotropi therml prmeters for ll non-hydrogen toms. Crystllogrphi lultions S2

3 were rried out using SHELXTL. The rystl dt hs een deposited in the CCDC under the following referene numers: ( ipr PN Me P)FeCl 2 ( ), ( ipr PN Me P)Fe(H)BH 4 ( ), 3 ( ), 4 ( nd ), 5 ( ), nd CO 2-1 ( ). High pressure tlyti CO 2 hydrogention retions were performed using Prr 5500 series ompt retor with glss insert. Elementl nlyses were performed t Atlnti Mirol, In., in Norross, GA or Roertson Mirolit Lortory in Ledgewood, NJ. Preprtion of CO 2-1. A J. Young NMR tue ws hrged with ( ipr PNP)Fe(H)CO (1) (20 mg, mmol) in 2 ml pentne. The smple ws frozen t -198 C, degssed, nd 1 tm of ron dioxide dmitted to the tue. Upon wrming to mient temperture, the olor immeditely hnged from mgent to yellow. After 5 minutes, the exess ron dioxide gs ws removed in vuo, leving pproximtely 1 ml of the produt solution in the tue. The mixture ws then dented, onentrted to pproximtely 0.5 ml, nd ooled to -35 C overnight to fford 19 mg (85%) of CO 2-1 s yellow-ornge rystls. 1 H NMR (C 6 D 6 ): δ (t, 53.9 Hz, 1H, Fe-H), 0.80 (m, 6H, CH(CH 3 ) 2 ), 1.02 (m, 6H, CH(CH 3 ) 2 ), 1.09 (m, 6H, CH(CH 3 ) 2 ), 1.19 (m, 6H, CH(CH 3 ) 2 ), 1.36 (m, 2H, PCH 2 ), 1.71 (m, 2H, PCH 2 ), 1.77 (m, 2H, CH(CH 3 ) 2 ), 1.98 (m, 2H, NCH 2 ), 2.13 (m, 2H, CH(CH 3 ) 2 ), 3.29 (m, 2H, NCH 2 ). 13 C{ 1 H} NMR (C 6 D 6 ): δ 18.79, 19.18, 19.24, 19.29, 23.71, 26.21, 26.77, (t, 4.0 Hz), (CO 2 ), (Fe-CO). 31 P{ 1 H} NMR (C 6 D 6 ): δ (s). IR (KBr): 1891 (C O), 1727(O=C). Preprtion of ( ipr PN Me P)FeCl 2. FeCl 2 (167 mg, 1.32 mmol) ws dded to 40 ml THF solution of MeN{CH 2 CH 2 P( i Pr) 2 } 2 (421 mg, 1.32 mmol) t mient temperture nd stirred for 11 hours. The resulting yellow solution ws then filtered, the filtrte onentrted to 10 ml nd lyered with pproximtely 5 ml pentne. Cooling overnight t -35 C fforded 378 mg (64%) of ( ipr PN Me P)FeCl 2 s olorless rystlline solid. Mgneti suseptiility: 4.72 B (Evns S3

4 Method). 1 H NMR (THF-d 8 ): δ 73.9, 63.1, 46.8, 4.36, Anl. Cld. for C 17 H 39 Cl 2 FeNP 2 : C, 45.76%; H, 8.81%, N, 3.14%. Found: C, 45.57%, 8.54%, 3.02%. Preprtion of ( Cy PN Me P)FeCl 2. This ompound ws prepred in mnner identil to ( ipr PN Me P)FeCl 2 using MeN{CH 2 CH 2 P(Cy) 2 } 2 (210 mg, mmol) nd FeCl 2 (52 mg, mmol) whih fforded 244 mg (98%) of olorless powder. Mgneti suseptiility: 4.96 B (Evns Method). 1 H NMR (C 6 D 6 ): δ 69.7, 55.6, 6.57, 4.86, 0.81, -0.13, -2.48, Anl. Cld. for C 29 H 55 Cl 2 FeNP 2 : C, 57.43%; H, 9.14%, N, 2.31%. Found: C, 57.52%, 8.86%, 2.31%. Preprtion of ( Cy PN Me P)Fe(H)(BH 4 ). ( Cy PN Me P)FeCl 2 (159 mg, mmol) ws dissolved in solvent mixture ontining 5 ml etonitrile nd 15 ml ethnol to provide red-purple solution. Upon ooling the solution in n in ie-wter th, exess NBH 4 (117 mg, 3.14 mmol) ws dded in one portion. Gs evolution ws immeditely oserved nd the solution turned rown. After stirring t mient temperture for one hour, the rown retion mixture ws pled under redued pressure to remove the voltiles. The residue ws triturted with pentne (3 5 ml), extrted with 15 ml of pentne, nd the drk rown solution onentrted. Cooling to -35 C overnight fforded 101 mg (70%) of ( Cy PN Me P)Fe(H)(BH 4 ) s rown rystls. The sme proedure ws lso used to otin ( ipr PN Me P)Fe(H)(BH 4 ) whih ws identified y omprison to previously reported NMR spetr. Chrteriztion dt for ( Cy PN Me P)Fe(H)(BH 4 ): Anl. Cld. for C 29 H 60 BFeNP 2 : C, 63.17%; H,10.97%, N 2.54%. Found: C, 63.39; H, 11.00%; N, 2.61%. 1 H NMR (C 6 D 6 ): δ (r, 1H, Fe-H-B), (t, 53.1 Hz, 1H, Fe-H), (r, 1H, Fe-H-B), (m, 22H, PCy 2 ), 1.58 (s, 3H, NCH 3 ), (m, 6H, PCy 2 ), (m, 8H, PCy 2 ), (m, 4H, PCy 2 ), (m, 2H, CH 2 ), 2.30 (m, 2H, CH 2 ), 2.31 (m, 2H, PCy 2 ), 2.51 (m, 2H, CH 2 ), 2.75 (m, 2H, P Cy 2 ), 3.27 (m, 2H, CH 2 ), 4.36 (, 2H, BH 2 ). 13 C { 1 H} NMR S4

5 (C 6 D 6 ): δ 27.77, 27.80, 27.84, 27.91, 28.14, 28.21, 28.46, 28.49, 29.21, 29.68, 30.82, (PCy 2 ), 29.71, (CH 2 ) (NCH 3 ). 31 P { 1 H} NMR (C 6 D 6 ): δ 87.2 (s, PCy 2 ). Preprtion of ( Cy PN Me P)Fe(H)CO(BH 4 ) (3). A 25 ml hevy wlled glss vessel ws hrged with ( Cy PN Me P)Fe(H)BH 4 (39 mg, mmol) in 8 ml pentne. The smple ws frozen t -198 C, degssed, nd 1 tm of ron monoxide dmitted to the vessel. Upon wrming to mient temperture the olor hnged from rown to yellow nd within 30 minutes yellow rystlline solids preipitted. Most of the voltiles were removed quikly under vuum, leving pproximtely 3 ml pentne in the vessel. Under N 2 the mixture ws dented nd the yellow rystlline residue ws wshed with 2 3 ml of pentne. Following ir-drying, the yellow solid ws riefly dried under vuum (less thn 5 minutes) to fford 38 mg (92%) of 3. The sme proedure ws lso used to otin ( ipr PN Me P)Fe(H)CO(BH 4 ) (3) whih ws identified y omprison to previously reported NMR spetr. 1,1 Chrteriztion dt for ( Cy PN Me P)Fe(H)CO(BH 4 ) (3): Anl. Cld. for C 30 H 60 BFeNOP 2 : C, 62.19%; H, 10.44%, N, 2.42%. Found: C, 61.98; H, 10.18%; N, 2.24%. 1 H NMR (C 6 D 6 ): δ (t, 52.8 Hz, 1H, Fe- H), (r, 4H, BH 4 ), (m, 8H, PCy 2 ), (m, 4H, PCy 2 ), (m, 32H, CH 2 & PCy 2 ), 2.01 (s, 3H, NH 3 ), 2.02 (m, 2H, PCy 2 ), 2.18 (m, 2H, CH 2 ), 2.74 (m, 2H, PCy 2 ), 3.07 (m, 2H, CH 2 ). 13 C { 1 H} NMR (C 6 D 6 ): δ 27.26, 27.30, 27.35, 27.65, 27.91, 28.21, 28.25, 28.94, 29.10, 31.48, 37.13, (PCy 2 ), (NCH 3 ), 31.06, (CH 2 ), CO resonne not loted. 31 P { 1 H} NMR (C 6 D 6 ): δ (s, PCy 2 ). Preprtion of ( ipr PN Me P)Fe(H) 2 CO (4). A 20 ml sintilltion vil ws hrged with ( ipr PN Me P)Fe(H)CO(BH 4 ) (3) (20 mg, mmol) in 5 ml of THF. Exess NEt 3 (pproximtely 500 µl) ws dded to the solution nd stirred for 20 minutes. The voltiles were then removed under vuum nd the residue extrted with 2 ml of pentne. Cooling the S5

6 solution to -35 o C overnight fforded 16 mg (89%) of 4 s yellow needles. The ompound ws hrterized y omprison to previously reported NMR spetr. 1,1 Preprtion of ( ipr PN Me P)Fe(H)CO(HCO 2 ) (5). A J. Young NMR tue ws hrged with ( ipr PN Me P)Fe(H) 2 CO (4) (30 mg, mmol) in 1 ml of C 6 D 6. The smple ws frozen t -198 C, degssed, nd 1 tm of ron dioxide dmitted to the tue. The tue ws wrmed to mient temperture nd llowed to sit for pproximtely 20 minutes. The voltiles were removed in vuo, leving yellow residue. The residue ws extrted with pentne (3 2 ml), onentrted to pproximtely 1 ml, nd ooled to -35 C overnight to fford 30 mg (90%) of 5 s yellow rystls. Anl. Cld. for C 19 H 41 FeNO 3 P 2 : C, 50.79%; H, 9.20%; N, 3.12%. Found: C, 50.72%; H, 8.47%; N, 3.04%. Mjor Isomer: 1 H NMR (C 6 D 6 ): δ (t, 52Hz, 1H, Fe-H), 0.90 (m, 6H, CH(CH 3 ) 2 ), 1.13 (m, 6H, CH(CH 3 ) 2 ), 1.18 (m, 6H, CH(CH 3 ) 2 ), 1.45 (m, 6H, CH(CH 3 ) 2 ), (m, 4H, CH(CH 3 ) 2 ), 1.83 (s, 3H, CH 3 ), (m, 6H), 2.31 (m, 2H), 9.22 (s, 1H, HCO 2 ). 13 C{ 1 H} NMR (C 6 D 6 ): δ 18.24, 19.35, 20.03, 20.74, 25.95, 26.38, 26.86, 45.32, 65.51, (HCO 2 ), (CO). 31 P{ 1 H} NMR (C 6 D 6 ): δ (s). Seleted dt for minor isomer: 1 H NMR (C 6 D 6 ): δ (t, 51.4 Hz, 1H, Fe-H), 9.11 (s, 1H, HCO 2 ). 13 C{ 1 H} NMR (C 6 D 6 ): δ (CO). 31 P{ 1 H} NMR (C 6 D 6 ): δ (s). Smple spetr ontining ll peks for the mjor nd minor isomers re provided lter in the Supporting Informtion. Generl Methods for Ctlyti CO 2 Hydrogention Studies. In gloveox, 50 ml glss retor liner ws hrged with tlyst s stok solution in THF ( M), orresponding mount of DBU, Lewis id nd 5 ml to 10 ml THF. The ylinder liner ws pled into the Prr retor nd the vessel seled. The retor ws removed from the dry ox nd pressurized with 69 tm of 1:1 CO 2 :H 2 mixture t mient temperture. The retor ws then heted nd stirred t 80 C for the indited time. The retion ws stopped y removl from the het soure nd S6

7 venting of the gses. The ontents of the retor were then quikly trnsferred to 100 ml round ottom flsk with ssistne of D 2 O to dissolve the solid produts. Then ll of the voltiles were removed under redued pressure. The residue ws dissolved in D 2 O, nd 10 to 400 µl DMF ws dded s n internl stndrd for quntifition of the formte produt y 1 H NMR spetrosopy. Firly lrge mounts of D 2 O my e required to ompletely dissolve the generted formte. S7

8 Tle S1. Sreening of ses for CO 2 hydrogention tlyzed y 1. CO 2 + H mol 1 100eq Bse, THF, 80 o C, 4 h O H O - BseH + Bse d TON Yield (%) e KHMDS 4 4 KO t Bu Cs 2 CO NEt Pyridine 1 1 DABCO DBU Retion onditions: 69 tm of CO 2 :H 2 (1:1), 0.78 μmol of 1 in 5 ml THF ( M) t 80 o C. Formte prodution quntified y 1 H NMR spetrosopy. KHMDS is potssium is(trimethylsilyl)mide, DABCO is 1,4-diziylo[2.2.2]otne nd DBU is 1,8- Diziylo[5.4.0]unde-7-ene. d Et 3 N nd pyridine were dried over CH 2 nd moleulr sieves respetively nd distilled under redued pressure. DABCO were purified y sulimtion (50 C, 0.02 mr). DBU ws dried over CH 2 nd distilled prior to use. Cs 2 CO 3 ws dried under vuum t 50 C overnight. e Reported yield is sed on se (se/foremte = 1:1). Tle S2. Lewis id optimiztion for CO 2 hydrogention tlyzed y 1. CO 2 + H mol eq DBU, X LiBF 4, THF, 80 o C, 16 h O H O - DBUH + DBU/LiBF 4 TON Yield (%) d no LiBF / / / / / / / Retion onditions: 69 tm of CO 2 :H 2 (1:1), 0.78 μmol of 1 in 5 ml THF ( M), 180 mg DBU t 80 o C. Formte prodution quntified y 1 H NMR spetrosopy. Reported vlues re the verge of three trils. d Reported yield is sed on se (se/formte = 1:1) S8

9 Tretment of HCO 2-1 with LiBF 4 nd DBU. A J. Young NMR tue ws hrged with 3 mg of HCO 2-1 in pproximtely 1 ml of THF-d 8. Then, 3 eq of LiBF 4 ws dded under n N 2 tmosphere. After 20 minutes, pproximtely 40 eq of DBU ws lso dded. The retion ws monitored y 31 P nd 1 H NMR spetrosopy over the ourse of 16 hours. N-H HCO 2 HCO 2 N-H HCO 2 N-H Fe-H Figure S1. () 1 H NMR spetr of HCO 2-1, () fter ddition of 3 eq LiBF 4, () fter ddition of 40 eq DBU. S9

10 NMR sle tlyti CO 2 hydrogention retion with HCO 2-1. A J. Young NMR tue ws hrged with 5 mg of HCO 2-1 in pproximtely 1 ml of THF-d 8. Then 3 eq of LiBF 4 nd 40 eq of DBU were dded to the smple. The smple ws frozen t -198 C, degssed, nd 1 tm eh of ron dioxide nd dihydrogen were dmitted to the tue. The smple ws wrmed to mient temperture nd monitored y 31 P nd 1 H NMR spetrosopy. HCO 2 N-H * N-H N-H d + HDBU - HCO 2 N-H Fe-H d Figure S2. () 1 H NMR spetr of HCO 2-1, () fter ddition of 3 eq LiBF 4, () fter ddition of 40 eq DBU, (d) 16 h fter ddition of 1 tm CO 2 /H 2. *denotes C 6 H 6 from gloveox tmosphere. S10

11 NMR sle tlyti CO 2 hydrogention retion with 3. A J. Young NMR tue ws hrged with 6 mg of 3 in pproximtely 1 ml of THF-d 8. Then, 3 eq of LiBF 4 nd 40 eq of DBU were dded to the smple. The smple ws frozen t -198 C, degssed, nd 1 tm eh of ron dioxide nd dihydrogen were dmitted to the tue. The smple ws wrmed to mient temperture nd monitored y 31 P nd 1 H NMR spetrosopy d e Figure S3. () 31 P NMR spetr of 3, () fter ddition of 3 eq LiBF 4, () fter ddition of 40 eq DBU, (d) 1.5 h fter ddition of 1 tm CO 2 /H 2, (e) 16 h fter ddition of 1 tm CO 2 /H 2. S11

12 HCO 2 5 d e HCO d e Figure S4. () 1 H NMR spetr of 3, () fter ddition of 3 eq LiBF 4, () fter ddition of 40 eq DBU, (d) 1.5 h fter ddition of 1 tm CO 2 /H 2, (e) 16 h fter ddition of 1 tm CO 2 /H 2. Free formte ( + HDBU HCO 2 ) is seen upon CO 2 /H 2 ddition (d nd e). S12

13 NMR sle tlyti CO 2 hydrogention retion with 4. A J. Young NMR tue ws hrged with 6 mg of 4 in pproximtely 1 ml of THF-d 8. Then 3 eq of LiBF 4 nd 40 eq of DBU were dded to the smple. The smple ws frozen t -198 C, degssed, nd 1 tm eh of ron dioxide nd dihydrogen were dmitted to the tue. The smple ws wrmed to mient temperture nd monitored y 31 P nd 1 H NMR spetrosopy over the ourse of 16 hours. 4 5 d 5 Figure S5. () 31 P NMR spetr of 4, () fter ddition of 3 eq LiBF 4 nd 40 eq DBU, () 1.5 h fter ddition of 1 tm CO 2 /H 2, (d) 16 h fter ddition of 1 tm CO 2 /H 2. S13

14 * HCO 2 5 d HCO d Figure S6. () 1 H NMR spetr of 4, () fter ddition of 3 eq LiBF 4 nd 40 eq DBU, () 1.5 h fter ddition of 1 tm CO 2 /H 2, (d) 16 h fter ddition of 1 tm CO 2 /H 2. S14

15 Figure S7. Prtil 1 H NMR spetrum for 4 showing the is- nd trns-isomers isomers in C 6 D 6. Figure S8. Prtil 1 H-oupled 13 C NMR spetrum of ( ipr PN Me P)Fe(H) 2 13 CO (4) showing isnd trns-isomers in C 6 D 6. S15

16 5 mjor 5 minor Figure S9. Prtil 1 H NMR spetrum for 5 showing mjor nd minor isomers in C 6 D 6. Note: 4 present in smll mount t ppm. 5 mjor 5 minor Figure S10. Prtil 1 H-oupled 13 C NMR spetrum of ( ipr PN Me P)Fe(H) 13 CO(HCO 2 ) (5) showing mjor nd minor isomers in C 6 D 6. S16

17 N-CH 3 Figure S11. NOESY NMR spetrum for 5 in C 6 D 6 (mixing time 300ms t 22 C). S17

18 Tretment of 5 with DBU, H 2 nd LiBF 4. A J. Young NMR tue ws hrged with 3 mg of 5 in pproximtely 1 ml of THF-d 8. 5 eq of DBU were dded to the smple, then the tue ws frozen t -198 C, degssed, nd 1 tm of dihydrogen ws dmitted. The smple ws wrmed to mient temperture nd monitored y 31 P nd 1 H NMR spetrosopy. After 16 h, 3 eq of LiBF 4 ws dded to the smple nd the dihydrogen tmosphere rehrged Figure S12. () 31 P NMR spetr of 5, () 16 h fter ddition of 5 eq DBU nd 1 tm H 2, () 10 min fter ddition of 3 eq LiBF 4. S18

19 5 * * - HCO 2 * Figure S13. () 31 P NMR spetr of 5, () 16 h fter ddition of 5 eq DBU nd 1 tm H 2, () 10 min fter ddition of 3 eq LiBF 4. Free formte ( + HDBU HCO 2 ) is seen upon CO 2 /H 2 ddition (). * denotes C 6 H 6 from gloveox tmosphere. S19

20 Tretment of 5 with LiBF 4. A J. Young NMR tue ws hrged with 3 mg of 5 in pproximtely 1 ml of THF-d 8. Then 3 eq of LiBF 4 ws dded under n N 2 tmosphere nd the smple monitored y 31 P nd 1 H NMR spetrosopy. 4 5 Figure S14. () 31 P NMR spetr of 5, () 10 min fter ddition of 3 eq LiBF 4, () 2 h fter ddition of 3 eq LiBF 4. Note: 4 present in smll mount in (). S20

21 * 5 4 Figure S15. () 1 H NMR spetr of 5, () 10 min fter ddition of 3 eq LiBF 4, () 2 h fter ddition of 3 eq LiBF 4. Note: 4 present in smll mount in (), * denotes C 6 H 6 from gloveox tmosphere. S21

22 X-ry Crystllogrphy Figure S16. Moleulr strutures of ( ipr PN Me P)FeCl 2 t 30% ellipsoids. Hydrogen toms not tthed to iron or oron hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ): Fe(1)-P(1) (8), Fe(1)-P(2) (7), Fe(1)-N(1) 2.222(2), Fe(1)-Cl(1) (7), Fe(1)-Cl(2) (7), P(1)-Fe(1)-P(2) (3), Cl(1)-Fe(1)-Cl(2) (3). Figure S17. Moleulr strutures of ( ipr PN Me P)Fe(H)BH 4 t 30% ellipsoids. Hydrogen toms not tthed to iron or oron hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ) ( ipr PN Me P)Fe(H)BH 4 : Fe(1)-P(1) 2.193(2), Fe(1)-P(2) 2.183(2), Fe(1)-N(1) 2.079(2), Fe(1)- H(42) 1.62(6), Fe(1)-H(44) 1.67(5), Fe(1)-H(50) 1.58(5), P(1)-Fe(1)-P(2) (6), H(42)-B(1)- H(44) 105(4). S22

23 Figure S18. Moleulr struture of 3 t 30% ellipsoids. Hydrogen toms not tthed to iron or oron hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ) for 3: Fe(1)-P(1) (6), Fe(1)-P(2) (7), Fe(1)-N(1) 2.136(1), Fe(1)-H(20) 1.47(2), Fe(1)-H(33) 1.81(3), Fe(1)-C(18) 1.728(2), C(18)-O(1) 1.162(2), P(1)-Fe(1)-P(2) (3), N(1)-Fe(1)-C(18) (7). Figure S19. Moleulr struture 4 t 30% ellipsoids. Hydrogen toms not tthed to iron hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ): Fe(1)-P(1) (8), Fe(1)- P(2) (8), Fe(1)-N(1) 2.123(2) Fe(1)-H(1) 1.51(2), Fe(1)-H(2) 1.42(3), Fe(1)-C(1) 1.748(3), C(1)-O(1) 1.134(4), P(1)-Fe(1)-P(2) (3), N(1)-Fe(1)-H(1) 171.8(9), C(1)-Fe(1)- H(2) 170(1). S23

24 Figure S20. Moleulr struture of 5 t 30% ellipsoids. The hydrogen tom tthed to iron ws freely refined while tht tthed to C(1) ws lulted. All other hydrogen toms hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ) for 3: Fe(1)-P(1) 2.212(3), Fe(1)-P(2) 2.227(3), Fe(1)-N(1) 2.14(1), Fe(1)-H(20) 1.40(8), Fe(1)-C(2) 1.68(1), Fe(1)-O(1) 2.019(8), C(2)-O(3) 1.19(2), C(1)-O(1) 1.27(2), C(1)-O(2) 1.20(2), P(1)-Fe(1)-P(2) 163.8(1), N(1)-Fe(1)-C(2) 168.8(5); O(1)-Fe(1)-H(20) 177(4). Figure S21. Moleulr struture of CO 2-1 t 30% ellipsoids. Hydrogen toms not tthed to iron nd o-rystllized pentne moleule hve een removed for lrity. Seleted ond lengths (Å) nd ngles ( ): Fe(1)-P(1) (9), Fe(1)-P(2) (9), Fe(1)-N(1) 2.037(2), Fe(1)-C(18) 1.720(3), Fe(1)-H(24) 1.45(3), Fe(1)-O(1) 2.113(2), C(17)-O(1) 1.262(4), C(17)-O(2) 1.212(4), C(17)-N(1) 1.513(4), C(18)-O(3) 1.167(4), P(1)-Fe(1)-P(2) (4), N(1)-Fe(1)-C(18) 175.1(1), N(1)-Fe(1)-O(1) 65.75(9), O(1)-C(17)-O(2) 131.9(3). S24

25 Referenes 1. () Werkmeister, S.; Junge, K.; Wendt, B.; Alerio, E.; Jio, H.; Bumnn, W.; Junge, H.; Gllou, F.; Beller, M. Angew. Chem. Int. Ed. 2014, 53, 8722; () Bornshein, C.; Werkmeister, S.; Wendt, B.; Jio, H.; Alerio, E.; Bumnn, W.; Junge, H.; Junge, K.; Beller, M. Nt. Commun. 2014, 5, 4111; () Koehne, I.; Shmeier, T. J.; Bielinski, E. A.; Pn, C. J.; Lgditis, P. O.; Bernskoetter, W. H.; Tkse, M. K.; Würtele, C.; Hzri, N.; Shneider, S. Inorg. Chem. 2014, 53, Pngorn, A. B.; Girdello, M. A.; Grus, R. H.; Rosen, R. K.; Timmers, F. J. Orgnometllis 1996, 15, Sndström, J. Dynmi NMR Spetrosopy; Ademi Press: New York, S25