A low-coordinate platinum(0)-germylene for E–H bond activation and catalytic hydrodehalogenation

A icle h ps://doi.o g/10.1038/s41467-024-53940-9 A low-coo dina e pla inum(0)-ge mylene o E–H bond ac i a ion and ca aly ic hyd odehalogena ion Sonia Bajo, En ique So o , Ma a Fe nández-Buenes ado, Joaquín López-Se ano &JesúsCampos Pai ing ansi ion me als and hea ie e ylenes (Si, Ge, Sn, Pb) holds g ea po en ial o coope a i e bond ac i a ion and ca alysis. In his wo k, we in es iga e he eac i i y o a low-coo dina e P (0)/Ge(II) sys em ha eme ges om he eac ion be ween he monoliga ed pla inum(0) p ecu so [(PMe 2 A Dipp2)P (olefin)] wi h ge mylene dime [A Dipp2GeCl] 2 (whe e A Dipp2 =C 6 H 3 −2,6-(C 6 H 3 −2,6-iP 2 ) 2 ). The esul ing complex e eals abili y o coope a i e bond ac i a ion. S oichiome ic eac ions wi h dihyd ogen, wa e , me hanol, ammonia and alkynes un eil he o ma iono P (II)-ge mylcom- pounds, cha ac e ized by dis inc isome ic o ms, whose flexibili y de i es om he pa icula ly low-coo dina ion. We explo e i s ca aly ic po en ial in he hyd odehalogena ion o alipha ic, a oma ic and main-g oup halides unde dihyd ogen a mosphe e using bo h he mal and pho ochemical condi ions, demons a ing p omising con e sions e en o mo e challenging alkyl chlo ides. He e obime allic complexes cons uc ed a ound a ansi ion me al andalow- alen maing oup elemen ha ega ne ed eneweda en ion owing o hei s uc u e, bonding, and eac i i y1,2.No ably,hea ie di alen g oup 14 elemen s (Si, Ge, Sn, Pb; hea ie e ylenes) com- binedwi h ansi ion me als ep esen p ominen and endyexamples wi hin his ca ego y3. Despi e being disco e ed ea lie han hei ligh e ca bene coun e pa s4, hea ie e ylenes we e swi ly o e - shadowed by hei ca bon e sions, p ima ily due o he e ficacy o hose as innocen ligands in me al ca alysis5. Howe e , i is p ecisely he unique abili y o hea ie e ylenes o unc ion as non-innocen pla o ms ha se s hem apa . These com- pounds exhibi a biphilic cha ac e , allowing hem o in e ac wi h ansi ion me als by bo h dona ing and ecei ing elec on densi y. This esul s in a flexible bonding a angemen ha opens up nume ous oppo uni ies o coope a i e eac i i y6. In ac , he e obime allic compoundso his kind ha edemons a ed an ou s andingcapaci y o ac i a e pa icula ly ine bonds, exemplified by he clea age o he highly obus N–H bonds in ammonia. While achie ing such ac i a ion emains a challenge o ansi ion me al complexes7–9, ecen b eak h oughs ha e been made unde mild condi ions o Ni/Si10 and I /Ge11 pai s (Fig. 1). In addi ion, an ou e sphe e clea age o he N–H bond in ammonia upon coo dina ion o a Ni/Ge sys em has also been ecen ly disclosed12. Despi e hese successes, he ansi ion o hese coope a i e designs om s oichiome ic bond ac i a ion o ca aly ic egimes has been no ably es ic ed13–16. We hypo hesize ha he limi ed numbe o ca aly ic applica ions is pa ly a ibu ed o he coo dina i ely sa u- a ed en i onmen s p e ailing a he wo ac i e si es in mos sys ems (as hose in Fig. 1, op). In he same ein, base-s abilized e ylene agmen s a e ypically employed o enhanced s abili y17–20,albei a he expense o quenching hei biphilic na u e and, consequen ly, hei ue po en ial o bime allic coope a ion. A con as , in an e o o access pa icula ly low-coo dina e complexes, ou p io wo k combined [(A Mes2) 2 Ge:] (A Mes2 =C 6 H 3 −2,6-(C 6 H 2 −2,4,6-Me 3 ) 2 ) and[RhCl(COD)] 2 (COD = 1,5-cyclooc adiene)21. Albei he hodium si e did no e ain any ligand apa om he ge mylene, he esul ing sys- em ea u ed his me al s ongly emb aced by wo la e al a yl ings o he e phenyl subs i uen s. While ac i e in e e sible and coope a i e Recei ed: 13 May 2024 Accep ed: 25 Oc obe 2024 Check o upda es Ins i u o de In es igaciones Químicas (IIQ), Depa amen o de Química Ino gánica and Cen o de Inno ación en Química A anzada (ORFEO-CINQA), Uni- e sidad de Se illa and Consejo Supe io de In es igaciones Cien íficas (CSIC), Se illa, Spain. e-mail: [email protected];[email protected] Na u e Communica ions | (2024) 15:9656 1 1234567890():,; 1234567890():,; C–H bond clea age eac ions,bo h hodium and ge manium exhibi ed coo dina i e sa u a ion, es ic ing i s ca aly ic capaci y, hough we could un eil hei ac i i y owa ds semi-hyd ogena ion eac ions o alkynes22. In pu sui o a genuinely low-coo dina e sys em wi h enhanced eac i i y (Fig. 1, bo om), ou ocus has now shi ed o a low- coo dina e pla inum(0) complex bea ing ou s e ically conges ed e phenyl phosphine PMe 2 A Dipp2 (A Dipp2 =C 6 H 3 −2,6-(C 6 H 3 −2,6-iP 2 ) 2 ), andalabile e -bu yle hyleneligand23.Tomi iga e he excessi es e ic p o ec ion p e iously p o ided by [(A Mes 2 ) 2 Ge:], we ha e chosen he mono- e phenyl ge mylene dime [A Dipp2GeCl] 2 24.In hiss udy,we in es iga e he s oichiome ic eac i i y o his low-coo dina e sys em owa ds dihyd ogen, wa e , me hanol, ammonia, and ace ylenes. Fu - he mo e, we explo e i s po en ial as a ca alys in he dehalogena ion o alkyl, a yl, and main g oup halides—an impo an ans o ma ion in he ealms o en i onmen al emedia ion, o ganic syn he ic me ho- dology, and iso opic labeling25. Resul s Syn hesis and cha ac e iza ion o low-coo dina e P (0)/Ge(II) compound The low-coo dina e P (0) compound [(PMe 2 A Dipp2)P (TBE)] (TBE = e -bu yl e hylene) eadily eac s wi h ge mylene dime [A Dipp2GeCl] 2 in benzene o yield an in ense ed solu ion due o quan i a i e o - ma ion o compound 1(Fig. 2a). This highly educed species is cha - ac e ized by a 31P{1H} NMR esonance a 17.9ppm, mildly shi ed om i s p ecu so (δ23.7 ppm), and flanked by 197P sa elli es ha accoun ●Ve y low-coo dina ion ●E–H bond ac i a ion H2H2OMeOH NH 3RCCH ●Ca aly ically ac i e Fig. 1 | T ansi ion me al/hea ie e yelene coope a i e eac i i y. [Top] P e- ious examples o s oichiome ic ammonia N–H bond ac i a ion ac oss ansi ion me al(TM)-hea ie e ylene(HT) bonds o ele ance o he p esen con ibu ion. [Bo om] This wo k: Low-coo dina e P (0)-ge mylene complex ac i e in s oichio- me ic bond ac i a ion and hyd odehalogena ion ca alysis (iP = isop opyl; Bu = e bu yl). (a) (b) Fig. 2 | A low coo dina e pla inum-ge mylene. a Syn hesis o pla inum(0)-ge - mylene compound 1by he eac ion o [(PMe 2 A Dipp2)P (TBE)] and [A Dipp2GeCl] 2 . bMajo de o ma ion densi ies om EDA-NOCV analysis o 1(0.002 a.u. iso alue). NOCV 1 and 3 show elec on flow om he P agmen o he ge mylene ( ed o blue lobes). NOCV 2 co esponds o σdona ion om he ge mylene o he P agmen . Calcula ions a he ZORA-BP86-D3BJ/TZVP//PCM-BP86-D3BJ/de 2-SVP le el o heo y. Elec on densi y flow om ed o blue egions. (NOCV = Na u al O bi al o Chemical Valence). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 2 o a ema kable 1J PP coupling cons an o 5376 Hz (c. . 4414 Hz in he p ecu so ). We a ibu e his p onounced inc ease in 1J PP o an enhanced s-cha ac e o he P –P bond as he olefinis eleased—e i- denced by 1H NMR signals a 4.84, 4.93, and 5.80ppm due o ee TBE. Inspec ion o 1H NMR spec um indica es ee o a ion o he e phenyl g oups a bo h he phosphine and he ge mylene. No su p isingly, compound 1is highly uns able and all a emp s o isola e i in pu e o m om i s eac ion solu ion o o ob ain single c ys als o u he cha ac e iza ion we e un ui ul. Ne e heless, i s na u e was con- fi med by subsequen eac i i y s udies, and i s bonding a ionalized by compu a ional means. The DFT minimized geome y o 1(PCM-BP86-D3BJ/de 2-SVP; see Supplemen a y Da a 1 and also sec ion 6 o he Supplemen a y In o - ma ion) ea u es a dis o ed T-shaped coo dina ion a ound he P a om wi h a P—P —Ge angle o ca. 117°, and a P —Ge dis ance o 2.31 Å, conside ably sho e han he sum o he co alen adii o he elemen s (2.56 Å). S uc u ally, his is eminiscen o he T-shaped geome ies adop ed by NiE (E= Ge, Sn) complexes ecen ly desc ibed by Hadling on, which we e a ibu ed o he Z- ype na u e o he e y- lenes as ligands12. Inspec ion o he on ie o bi als shows ha he LUMO and LUMO+ 1 a e localized on he ge manium a om (Fig. S47). This sugges s ha he ge manium a om e ains i s elec ophilic cha - ac e , and is hus suscep ible o eac wi h nucleophiles, consis en wi h he s udies discussed la e . Fu he insigh s in o he o bi al in e ac ion by EDA-NOCV analyses26–28 (ZORA-BP86-D3BJ/TZVP//PCM- BP86-D3BJ/de 2-SVP) on he p e ious geome y using single A Dipp2ClGe and P (PMe 2 A Dipp) agmen s e eal h ee majo in e ac- ions, which accoun o ca. 80% o he o bi al in e ac ion, E o b (Fig. 2b). The fi s and hi d in e ac ions in e ms o ene gy (41.9 and 11.3% o E o b ) co espond o π-back dona ion P o Ge, whe eas σ dona ion om Ge o P comes second (26.6% E o b ), wi h an o e all ans e o 0.13 elec ons om he P agmen o he ge mylene (Hi sh eld). Reac i i y s udies and mechanis ic in es iga ions Nex , we examined he eac i i y o 1 owa ds he ac i a ion o E–H bonds(E =H, N, O) in dihyd ogen, wa e , me hanol, and ammonia. The eac ions p oceeded immedia ely e en a 25 °C, as e inced by a apid anish o he in ense ed colo upon subs a e addi ion o cleanly yield compounds 2, 3, 4, and 5 h ough coope a i e ac i a ion o H 2 ,H 2 O, MeOH, and NH 3 , espec i ely (Fig. 3). The elec ophilic e el si e binds a hyd ide, hyd oxide, me hoxide o amido g oup, whe eas he addi- ional hyd ide is loca ed a he pla inum cen e . I is impo an o no e ha he p esence o he wo ac i e si es is essen ial o bond ac i a ion. Thus, p ecu so [(PMe 2 A Dipp2)P (TBE)] is ine owa ds dihyd ogen, wa e , me hanol, o ammonia. The ge mylene dime does no eac wi h dihyd ogen ei he , al hough i eac s wi h wa e , me hanol, and ammonia. Howe e , as clea ly e inced by 1H NMR, hese eac ions led o in ac able mix u es o nume ous e phenyl-con aining species ha could no be iden ified. Subsequen addi ion o [(PMe 2 A Dipp2)P (TBE)] o hese eac ion mix u es only e ealed e y mino o ma ion (ca. 5–10%) o 3, 4, and 5. This con as s wi h he clean eac i i y o com- plex 1, disca ding he possibili y o P /Ge dissocia ion om 1 ollowed by mononuclea eac i i y and subsequen agmen coupling. The e o e, his clea ly speaks in a o o he no able capaci y o he low-coo dina e compound 1 o e ficien ly enable coope a i e bond ac i a ion e en s. We obse ed an in ense dec ease o he 1J PP coupling cons an (2 ,2671;3,2125;4, 2233; 5, 2429 Hz) a e bond ac i a ion, diagnos ic o o mal bime allic oxida i e addi ion o yield P (II)-ge myl com- pounds. The ge manium hyd ide, only p esen in compound 2,led o cha ac e is ic 1HNMRsignalsa 3.50(2 :dd,3J HP =30.7,3J HH =5.2Hz) and 5.90 ppm (2c: dd, 3J HP =10.9, 3J HH = 2.3 Hz). Besides, all species exhibi a dis inc i e 1H-NMR esonance due o he o ma ion o a P –hyd ide, in ensi ely low-shi ed in he case o compounds 2 (−15.7 ppm) and 5(−18.05 ppm), and mo e mode a ely o 2c (−5.6 ppm), 3(−7.45 ppm) and 4(−6.1ppm). This di e ence in chemi- cal shi s co ela es well wi h hei co esponding coupling pa e n. Hence, he hyd ide esonances o compounds 2 and 5showcases e y small coupling o phospho us (2J HP =5.2 (2 ), 16 (5) Hz) and la ge coupling o pla inum (1J HP =1608(2 ), 1092 Hz (5)). In s a k con as , he signal due o he P –Ho 3is cha ac e ized by 2J HP =180 and 1J HP = 297 Hz, and simila couplings a e eco ded o 2c and 4. These di e ences a e clea ly in o ma i e and sugges he gen- e a ion o wo dis inc isome s o 3/4 e sus 5, while he ac i a ion o H 2 yields he wo species, 2 and 2c,inca. 4 o 1 a io. The p e alen one (2 ) sha es s uc u e wi h 5,while he mino one(2c)fi s wi h 3and 4. Clea ly, he a o esaid alues o 2J HP indica e ha o he la e he phosphine and ge myl agmen s a e in cis-disposi ion, while a P/Ge ans a angemen co esponds o 2 and 5. We u he in es iga ed he exchange be ween isome s 2 and 2c by wo-dimensional exchange NMR spec oscopy (EXSY) wi hin he empe a u e ange P P iP iP Dipp Ge A Dipp Cl H H H2(0.5 ba ) 2 ans-isome iP iP P P Ge Cl Dipp iP iP iP iP 1 Dipp iP iP P P Ge A Dipp Cl OH H C6D6, 25 ºC < 5 min H2O(5 equi ) P P iP iP Dipp Ge A Dipp Cl NH2 H NH3(0.5 ba ) C6D6, 25 ºC, < 5min 35 Dipp iP iP P P Ge A Dipp Cl OMe H 4 MeOH (1 equi ) Dipp iP iP P P Ge A Dipp Cl H H 2c cis-isome + (4 : 1) Fig. 3 | Reac i i y s udies wi h 1. Coope a i e s oichiome ic eac i i y o compound 1 owa ds E–H (E = H, O, N) bonds o dihyd ogen, wa e , me hanol, and ammonia (iP = isop opyl; Dipp = 2,6-(C 6 H 3 −2,6-iP 2 ) 2 ;A Dipp2 =C 6 H 3 -2,6-(C 6 H 3 -2,6-iP 2 ) 2 ). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 3 be ween 25 and 65°C. An analysis o he eco ded da a led o a ΔH‡o 13.4 kcal/mol and a nega i e en opic pa ame e ΔS‡o −17.7 cal/mol K, which co esponds o an o e all ba ie ΔG 298 ‡o 18.6 kcal/mol (Fig. S36). The cis/ ans con o ma ions p oposed abo e we e co obo a ed by X- ay di ac ion s udies. We could g ow single c ys als om slow di usion o pen ane in o a sa u a ed benzene solu ion o 3(Fig. 4). Howe e , all ou a emp s o ob ain c ys als o good quali y o he dihyd ogen ac i a ion p oduc s 2 ailed, leading o highly diso de ed s uc u es om whe e we could no ex ac a eliable molecula model. To ci cum en his limi a ion, we decided o syn hesize a P (0)/Ge(II) analog b eaking he pseudo-symme y a ound he pla inum cen e . To do so we p epa ed he same P (0) p ecu so based on he ela ed PMe 2 A T ipp2 phosphine (A T ipp2 =C 6 H 3 -2,6-(C 6 H 3 -2,4,6-iP 3 ) 2 )and eac ed i wi h [A Dipp2GeCl] 2 . The esul ing analogous compound 1* equally eac ed wi h dihyd ogen leading o a a he simila spec o- scopic signa u e (see sec ion 2 o he Supplemen a yIn o ma ion) bu , in his case, allowing us o g ow single c ys als o good quali y o ans- isome in 2 * (Fig. 4). Compound 2 * exhibi s a pseudo-squa e plana coo dina ion, being he phosphine and ge myl agmen s in ans-disposi ion wi h a dis o ed angle o 165.37(3)°. The P –hyd ide could be loca ed a he di e ence elec on densi y Fou ie map wi h a d P -H o 1.51(6) Å. Opposi e o ha hyd ide, coo dina ion is comple ed by a weak κ1 in e ac ion P ···C A ene in e ac ion defined by a P –C7 dis ance o 2.370(3) Å ha compensa es he low sa u a ion a he me al. The o he hyd ide ligand esides on he ge manium cen e and could also be loca ed (d Ge-H = 1.38(4) Å). As an icipa ed om NMR analysis, he con o ma ion is comple ely di e en o compound 3,whichalso p esen s a pseudo-squa e plana coo dina ion. Howe e , he phos- phine and ge myl ligands a e now in cis-a angemen (P–P –Ge 97.66(2)°). A hyd ide ligand is loca ed a an almos ideal ans- disposi ion (P–P –H o 177(1)°), wi h a simila d P -H o 1.58(3)Å com- pa ed o2 *. Coo dina ion in 3iscomple edbya κ2in e ac ion wi h he flanking a yl ing (P –C7, 2.305(2) and P –C8, 2.595(3) Å). The mechanisms o hese E—H ac i a ions we e in es iga ed compu a ionally by DFT me hods (PCM-ZORA-B3PW91-D3BJ/de 2- TZVP + SARC-ZORA-TZVP(P )//PCM-BP86-D3BJ/de 2-SVP). The esul s o he calcula ions, summa ized in Fig. 5, e eal wo undamen ally di e en ou es, one sha ed by he ac i a ions o H 2 OandNH 3 ,and he second exclusi e o H 2 spli ing. The o me begins wi h ini ial coo - dina ion o wa e o ammonia o Ge, in ag eemen wi h he ge mylene agmen e aining i selec ophilicna u ein1despi e hedoublebond cha ac e o he P = Ge bond (see abo e). This is ollowed by E—H ac i a ion a he P —Ge bond, TS a , wi h ba ie s o 17.0 kcal mol−1 o Fig. 4 | X- ay di ac ion s udies o bond ac i a ion p oduc s. ORTEPs o com- plexes 2 * and 3. Mos hyd ogen a oms (excep hose de i ing om H 2 o H 2 O) a e excluded and iso-p opyl g oups a e ep esen ed in wi e ame o ma o cla i y. The mal ellipsoids a e se a 50% p obabili y. ΔG kcal mol-1 0.0 1+ E-H 1·H2 15.9 TSa 16.6 In 1 3.3 TSm 17.8 TSisom 12.2 2 -10.6 2c -8.0 1·OH2 13.9 3 -9.7 TSa 21.8 5 4.0 3 -11.1 1·NH3 1.4 TSa 17.0 TSisom 9.0 E=OH,NH 2 1,2-sh Fig. 5 | Compu a ional s udies o bond ac i a ion p ocesses. Calcula ed ene gy p ofiles o he ac i a ion o E—H bonds by 1. Magen a, cyan, and o ange (dashed) aces co espond o H 2 ,NH 3, and H 2 O ac i a ions, espec i ely. Calcula ions pe o med a he DFT PCM-ZORA-B3PW91-D3BJ/de 2-TZVP + SARC-ZORA- TZVP(P )//PCM-BP86-D3BJ/de 2-SVP le el o heo y. (iP = isop opyl; Dipp = 2,6- (C 6 H 3 -2,6-iP 2 ) 2 ;A Dipp =C 6 H 3 -2,6-(C 6 H 3 -2,6-iP 2 ) 2 ; TS = ansi ion s a e). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 4 H 2 O and 21.8 kcal mol−1 o NH 3 . We also conside ed he po en ial in ol emen o up o h ee wa e molecules in he ac i a ion o H 2 O, howe e , he ene gy ba ie s a e a bes sligh ly highe han he epo ed abo e o one H 2 O molecule (see Fig. S51). These ba ie s a e highe o ac i a ions in which he o ming P ···H bond is ans o P (27.7 and 33.8 kcalmol−1 o he wa e and ammonia sys ems espec- i ely), which lead o cis isome s o 3and 5. Thus, while o ma ion o he expe imen ally obse ed isome 5is accoun ed o by he ac i a- ion depic ed in Fig. 5(5is he kine ic and he modynamic isome ), o ma ion o 3 equi es isome iza ion o he kine ic isome , 3 (Ge ans o P), TS isom , h ough a ba ie o ca. 20 kcal mol−1. We calcula ed simplified models o he cis and ans isome s o 3and 5by eplacing he diisop opyl agmen s by H and he e phenyl subs i uen on he Ge by phenyl and in bo h cases, he cis isome esul ed he mos s able by ca. 4 kcal mol−1, sugges ing a ole o sub le s e ic e ec s in he ela i e s abili y o he isome s in he eal sys ems. As such, we pe - o med con o ma ional analysis wi h ex ended igh -binding me hods in addi ion o DFT op imiza ions o ob ain ela i e ene gies ha a e consis en wi h he expe imen s29. In u n, ac i a ion o H 2 equi es ini ial coo dina ion o H 2 o P and oxida i e addi ion a he ansi ion me al, TS a , which has a ba ie o 16.6 kcal mol−1,andyieldsaP II dihyd ide, In 1 ha eadily unde - goes 1,2-shi ia TS m (ΔG‡=14.5kcalmol −1) o yield 2 in equilib ium wi h 2c h ough a ba ie o ca 20kcal mol−1(TS isom ), in ag eemen wi h he EXSY expe imen s. Al e na i ely, H 2 ac i a ion ac oss he P — Ge bond was disca ded as i has ba ie s well in excess o 25 kcalmol−1, aking place wi hou he p e ious o ma ion o he co esponding 1·H 2 adduc ( he coo dina ion o H 2 o Ge is no a minimum in he po en ial ene gy su ace). Oxida i e addi ion eac ions o e low- alen main g oup elemen s ep esen he a che ypalexample o ansi ion me al-like eac i i y o P-block elemen s30. Howe e , hese eac ions lead o highly s able oxidized species ha a ely exhibi e e sible beha io owa ds educ i e elimina ion31 and hus he possibili y o pa icipa e in edox ca aly ic cycles. F om he compu a ional ene ge ic p ofiles depic ed in Fig. 5i can be deduced ha , o he cu en sys em, egene a ion o he educed P (0)/Ge(II) compound 1could be plausible, as he o e all ene gies o he o wa d bime allic educ i e elimina ion p ocesses lie in heapp oxima e angeo 26–28 kcal/mol. Wi h his aim, we exposed compounds 2, 3, and 5 o dynamic acuum a a iable empe a u e, bu hei ins abili y p ecluded any defini i e conclusion. We could, howe e , demons a e ha hese compounds can be in e con e ed. Consequen ly, he addi ion o wa e (5 equi ) o ammonia (0.5 ba ) o compounds 2leads o he espec i e o ma ion o he oxida i e addi ion p oduc s 3and 5in a ound 99% spec oscopic yield (Fig. 6a). In u n, compound 3does no eac wi h dihyd ogen e en unde mild hea ing (60 °C), bu i con e s in o he hyd ido-amido complex 5 unde ammonia a mosphe e (Fig. 6a). The la e compound canno , ins ead, be con e ed unde he p esence o nei he H 2 o wa e , since decomposi ion o complex mix u es akes place du ing a emp s o emo e ammonia. Besides, we a emp ed he eac ion o hese oxidized compounds wi h e hylene. Once mo e, he hyd ide-amido species 5did no show any eac i i y a oom empe a u e and i decomposed unde hea ing a 80 °C. A a iance, dihyd ide 2and he hyd ide-hyd oxo compound 3 eac ed wi h e hylene (0.5ba ) leading o he clea age o he P ‒Ge bond and he o ma ion o he p e iously epo ed compound [(PMe 2 A Dipp2)P (C 2 H 4 ) 2 ](6)23 along wi h o he uniden ified ge manium species (Fig. 6b). These eac ions u he e ince he syne gis ic ac ion o pla inum and ge manium, he e h ough hyd ide mig a ion om he o me o he la e . In e es ingly, exposu e o p ecu so 1 o e hylene unde he same expe imen al condi ions did no p oduce any ace o bis-e hylene 6. Ins ead, i led o a new species cha ac e ized by a 31P{1H} esonance a 6.0 ppm exhibi ing a la ge 1J PP coupling o 4052 Hz ha sugges s no change in he oxida ion s a e o pla inum. Tha species gi es back p ecu so 1upon emo al o e hylene a mosphe e. Based on hese da a we a ibu e specula e he new compound o be an e hylene adduc o 1in which he weak π-a ene in e ac ion is sub- s i u ed by e hylene. None heless, he labili y o he coo dina ed e hylene is e inced, o ins ance, by eac ion wi h wa e , which eadily p oduces he hyd ide-hyd oxo compound 3. To comple e ou s oichiome ic s udies, we es ed he eac i i y wi h ace ylene and phenylace ylene, which o e ed a con as ing ou - come o he eac ion wi h e hylene. In his case, 1H NMRanalysis poin s ou o he inco po a ion o wo molecules o he alkynes pe P /Ge co e, which eadily yield compounds 7(Fig. 7) wi h apid ading o he in ense ed colo o 1. These species a e cha ac e ized by 31P{1H} esonances a 18.6 (7a,C 2 H 2 ) and 13.5 (7b,PhCCH),flanked by 197P sa elli es o 2180 and 2184 Hz, espec i ely. These educed alues o 1J PP compa ed o 1indica e ha he pla inum cen e has been oxidized o P (II), which oge he wi h he absence o any dis inc i e hyd idic esonance by 1H NMR, sugges a double 1,2-addi ion o he P /Ge co e ac oss he alkynes. Th ee 1H NMR esonances a 8.2 and 5.8 ppm o P Ge H H2 P Ge OH H3 P Ge NH2 H5 P Ge H H2 H2O NH3 P Ge NH2 H5 P Ge OH H3 NH3 X X X H2 H2 H2O P Ge (a) P Ge H H2 P Ge OH H3 (b) 1 C2H4 C2H4 C2H4 [P]P 6 [P]P 6 + + P Ge Cl A Dipp 1-C2H4 [P] o he Ge species o he Ge species Fig. 6 | S oichiome ic eac i i y s udies o mechanis ic in es iga ions. aIn e con e sion eac ions be ween compounds 2,3,and5and; (b) eac i i y s udies o compounds 1,2,and3wi h e hylene (mos ligands ha e been omi ed o cla i y). Fig. 7 | Reac i i y o 1 owa ds alkynes. Reac ion o compound 1wi h alkynes owa ds 1,2-pla inoge macyclobu adiene compounds 7, including ORTEP o bwhe emos hyd ogen a oms a e excluded and 2,6-a yl g oups a e ep esen ed in wi e ame o ma o cla i y. The mal ellipsoids a e se a 50% p obabili y. (iP = isop opyl; Dipp = 2,6-(C 6 H 3 -2,6-iP 2 ) 2 ;A Dipp =C 6 H 3 -2,6-(C 6 H 3 -2,6-iP 2 ) 2 ). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 5 one p o on each and a 5.46 ppm o wo p o ons in compound 7a,and a single wo-p o on peak a 6.6 ppm o 7b, a e a ibu ed o he newly o med diene agmen . The s uc u e o 7b was u he au hen ica ed by X- ay di ac ion s udies om c ys als g own om pen ane di usion in o i s sa u a ed benzene solu ion, confi ming a 1,2-pla inoge macyclobu adiene o - mula ion (Fig. 7).Thedis ancebe weenP andGeaccoun s o 3.4Å a e age, eflec ing hedisappea anceo heP –Ge bond, while he C–C bond dis ances o he ac i a ed alkynes a e o a ound 1.33 Å, in ag eemen wi h a diene o mula ion. The fluxional cha ac e o he s abilizing π-a ene con ac be ween a la e al a yl ing o he e phenyl phosphine and he unsa u a ed pla inum cen e is eflec ed by wo close bu di e en P –C ipso dis ances o 2.570(9) and 2.673(9) Å o he wo independen molecules o 7b p esen in he uni cell. The o ma- ion o hese compounds esemble he eac i i y o us a ed Lewis pai s (FLPs) wi h alkynes32, whe e 1,2-addi ion p oduc s a e common, including hose in P -based FLPs epo ed by ou g oup33.Theinse ion o alkynes in o ansi ion me al-ge myl compounds is also known34, while he eac ion o dige mynes wi h alkynes o p oduce dige ma- nium cyclobu adiene s uc u es has been epo ed be o e35,36.How- e e , hei ansi ion me al-con aining e sions, namely 1,2- me alage macyclobu adienes as he ones desc ibed he ein, ha e been sugges ed as ca aly ic in e media es, bu hei ansien na u e had o da e p e en ed isola ion37,38. A a iance, he highly conges ed en i - onmen o he p esen sys em con e s su ficien s abili y, allowing o hei ull cha ac e iza ion. Ca aly ic hyd o dehalogena ion The abo e eac i i y s udies clea ly demons a e he capaci y o 1 o coope a i ely ac i a e s ong bonds. We nex wonde ed whe he his could ansla e in o ca aly ic egimes, aided by i s low coo dina ion and hus i s abili y o bind addi ional subs a es o be ans o med. Recen s udies om he g oup o Bou issou e ealed ha coope a ion be ween an elec on- ich Pd(0) and a bound elec ophilic bo ane enabled he ca aly ic hyd odechlo ina ion o a yl chlo ides owa ds a enes39. This kind o Pd/bo ane syne gism is eminiscen o he mul i- si e coope a ion ope a ing in compound 1,and huswedeemedo in e es o explo e i s ca aly ic po en ial in hyd o dehalogena ion eac ions. We we e u he encou aged by s udies om he Llo e g oup, whe e mo e challenging C(sp3)–Clbondsinalkylchlo ides we e clea ed wi hin a ca aly ic cycle o educ i e cycliza ions using, once mo e, a coope a i e bime allic sys em (Co/Ni) wi h he key ea u e o a nucleophilic low- alen me al40. Be o e discussing ou own findings, i is wo h no ing ha mos ca aly ic dehalogena ion s udies ha e ocused on a yl halides, while alkyl halides wi h s onge C(sp3)–X bonds emain less in es iga ed, and in many cases, ca alys s ha e fi- cien ly dehalogena e a oma ic subs a es ail o con e alipha ic e sions41. Mo eo e , homogeneous ca alys s ha hyd odehalogena e alkyl halides ha e mos ly co e ed b omide subs a es42,43,showing li le success wi h chlo ide coun e pa s44. On hese g ounds, we decided o examine 1as a ca alys o he dehalogena ion o alipha ic halides, using 1-b omo-2,2-dime hylp o- pane as a benchma k subs a e (Table 1). We use dihyd ogen as a con enien sou ce o hyd ide since we al eady demons a ed ha i eadily o ms dihyd ide 2as a po en ial ac i e species.Basic condi ions a e na u ally equi ed o quench he elease o acid. Using 10 mol% ca alys loading, we each ull and clean con e sion owa ds 2,2- dime hylp opane using LiHMDS (HMDS = [N(SiMe 3 ) 2 ]− )as hebaseand benzeneassol en a e hea inga 80°C o ou hou s(en y4).The ac i i y o he pla inum p ecu so was conside ably educed (38%, en y 9), e incing he posi i e pa ne ship be ween pla inum and ge manium, while he e was no ac i i y o ge mylene o in he absence o ca alys . Al e na i ely, we ealized ha deb omina ion ook place a mode a e yields e en a oom empe a u e unde i adia ion wi h blue ligh (440 nm; see sec ion 5 o he Supplemen a y In o ma- ion o de ails). We hen examined he scope unde he mal condi ions wi h a se ies o alipha ic and a oma ic halides (Table 2). Chlo ides, b omides, and iodides could be dehalogena ed, bu he sys em e ealed no ca - aly ic ac i i y o hyd odefluo ina ion. To comple e hese s udies, we also es ed some ep esen a i e examples o E–Cl bonds (E = B, Si, Sn, P). No su p isingly,highe con e sions a e eached o alkylb omides, ollowed by iodides and chlo ides. Hyd odehalogena ion eac ions p oceed in good yields o unsubs i u ed alkyl halides. 1,2-diha- loe hanes a e cleanly con e ed o e hane wi hou any ace o monodechlo ina ion, while chlo oalkyl e he s we e quan i a i ely dechlo ina ed. Using 4-(chlo ome hyl)s y ene comple e con e sion was accomplished, leading o an ca. 1:1 mix u e o dechlo ina ion (4- me hyls y ene) and dechlo ina ion/hyd ogena ion (1-e hyl-4-me hyl- bencene) p oduc s. Fo a yl halides we un he eac ions a 100 °C since we no iced lowe con e sions. Good yields we e ob ained o mos subs a es, ha ing elec on dona ing and wi hd awing g oups o pa icula ly bulky subs i uen s. The ca alys showed ema kable unc ional g oup ole ance, including amine, ni ile, and e en ni o g oups, hough i exhibi s no eac i i y in he p esence o a ca boxylic o bo onic acids, which we a ibu e o hei in insic eac i i y wi h he base. We also es ed some ep esen a i e he e ocycles, which we e dehalo- gena ed wi h a iable ou comes, achie ing ull con e sion o 2-chlo opy idine. Finally, we a emp ed he dechlo ina ion o illus- a i e examples o E–Cl bonds (E = B, Si, Sn, P). Al hough chlo - oca echolbo ane was no al e ed, ime hylsilyl chlo ide, ime hyl in chlo ide, and di- e bu ylchlo ophosphine we e dechlo ina ed. Table 1 | Op imizing condi ions o hyd o deb omina ion wi h 1 En yaCa bSol en Base Condi ionscYield (%)d 12C 6 D 6 NaO Bu Δ26 22C 6 D 6 DABCO Δ0 32C 6 D 6 Cs 2 CO 3 Δ0 42C 6 D 6 LiHMDS Δ>99 52C 6 D 6 NE 3 Δ0 62C 6 D 6 NH 3 Δ0 72C 6 D 6 -Δ ace 8-C 6 D 6 LiHMDS Δ0 9[P ]C 6 D 6 LiHMDS Δ38 10 [Ge] C 6 D 6 LiHMDS Δ0 11 2CD 2 Cl 2 LiHMDS Δ0 12 2 h -d 8 LiHMDS Δ37 13 2Tol-d 8 LiHMDS Δ47 14 2C 6 D 6 LiHMDS hυ58 15 - C 6 D 6 LiHMDS hυ0 16 [P ] C 6 D 6 LiHMDS hυ10 17 [Ge] C 6 D 6 LiHMDS hυ0 aCa aly ic uns we e pe o med in J. Young NMR ubes wi h RB (0.054 mmol), ca alys (0.0054 mmol), base (0.054 mmol), H 2 (1 ba ), and sol en (500 μL). bP /Ge ca alys 2was gene a ed in si u by 2:1 mix u e o [(PMe 2 A Dipp2)P (TBE)] and [A Dipp2GeCl] 2 . Abb e ia ions [P ] and [Ge] e e o he la e p ecu so s. cTwo se s o condi ions we e used: ‘Δ’(80 °C) and ‘hυ‘(i adia ion 400 nm, 25 °C). dYield was calcula ed by 1HNMRusingC 6 Me 6 (4.4 mg) as in e nal s anda d. A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 6 We nex conduc ed p elimina y in es iga ions on he dehalo- gena ion mechanism, a fi s by pe o ming some addi ional s oi- chiome ic eac ions. P ecu so 1does no eac wi h neopen yl b omide o LiHMDS unde ca aly ically ele an condi ions, while i eadily adds H 2 o o m 2, as discussed abo e. In u n, dihyd ide 2is ine owa ds he a o esaid b omide (80 °C). In con as , i apidly eac s wi h LiHMDS, hough in he absence o o he subs a es, i e ol es in o a uniden ifiable mix u e o p oduc s. None heless, 1H NMR analysis e inces he absence o low- equency hyd idic eso- nances upon base addi ion (as also obse ed du ing NMR moni o ing o ca aly ic eac ions). Based on hese findings, we p opose a mechanism s a ing wi h he hyd ogena ion o 1by H 2 o o m 2 , which unde goes dep o o- na ion a P o yield an anionic species, A−(Fig. 8). Then, we conduc ed DFT calcula ions on he chemical sys em comp ising 2 ,neopen yl b omide (NpB ) as he subs a e, and HMDS-as he base (see Fig. S57 o de ails). Ou s udies sugges ha in e media e A− eac s wi h he subs a e ia a S N 2- ype ansi ion s a e in ol ing nucleophilic a ack by he pla inum a om o he CH 2 B ca bon o NpB o o m B·B −,a species ea u inganeu alme alliccomplexwi haneopen ylligandon he pla inum a om and one hyd ide on he ge manium a om. B omide elimina ion may hen ollow in he o m o LiB . Finally, educ i e elimina ion (RE) o yield he eac ion p oduc and egene a e 1 akes place om C, a species esul ing om 1,2-shi a B( eminiscen o he same s ep in he mechanism o H 2 ac i a ion by 1), which can be desc ibed as a squa e plana complex wi h one neopen yl and one hyd ide ligand coo dina ed in a cis ashion o a o mal P (II) ion, u he s abilized by one phosphine and one ge mylene. The a e-limi ing s ep o he cycle is he S N 2- ype eac ion o A− wi h NpB , o which we ha e calcula ed an ene gy ba ie o Table 2 | Scope o hyd odehalogena iona,b aCa aly ic uns we e pe o med in J.Young NMR ubes wi h RX (0.054 mmol), 2(p epa ed in si u; 0.0054 mmol), LiHMDS (0.054 mmol), H 2 (1 ba ) and C 6 D 6 (500 μL) a 80 °C (subs a es a, c, and d) o 100 °C (subs a es b) o 4 h. bO e all con e sion calcula ed by 1H NMR using hexame hylbenzene (4.4 mg) as in e nal s anda d. Values in b acke s e e o selec i i y o he hyd odehalogena ion p oduc , o a ios o mono s bisdehalogena ion. cIsobu ene as side-p oduc . dDiphenyle hane as side-p oduc . e1-e hyl-4-me hylbencene as side-p oduc . Mono s bisdehalogena ion. g Bu 2 P–P Bu 2 as side-p oduc . A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 7 29.2 kcalmol−1, consis en wi h he ca alysis no aking place a oom empe a u e and equi ing se e al hou s o comple e. None heless, we canno ye comple ely ule ou o he po en ial al e na i e pa hways, including adical ou es, as some hin s poin o hei po en ial in ol- emen : he hyd odeb omina ion o benzyl b omide led o an a ound 1:1 a io o e hylbenzene and he homocoupling p oduc 1,2-dipheny- le hane, while he homocoupling p oduc ( Bu 2 P–P Bu 2 )wasde ec ed using Bu 2 PCl as subs a e45. None heless, a mo e ho ough mechan- is ic pic u e, including open-shell sys ems, lies ou o he scope o he p esen con ibu ion and will be epo ed in due cou se. In summa y, we p o ide a me hod o access a low coo dina e pla inum(0)-ge mylene complex based on he kine ic s abiliza ion p o ided by bulky e phenyl subs i uen s. This exo ic design e ealed ema kable capaci y o coope a i e bond ac i a ion unde a he mild condi ions. S oichiome ic eac ions wi h dihyd ogen, wa e , me ha- nol, and ammonia demons a ed E–H bond clea age (E = H, N, O) ia wo dis inc coope a i e pa hways ha we e elucida ed by compu a- ional means. In u n, eac ion wi h alkynes led o a e 1,2-pla ino- ge macyclobu adienes, which we e ea lie p oposed as ca aly ic in e media es, bu ne e isola ed. The low-coo dina ion en i onmen allows o acile isome iza ion e en s, and indeed wo dis inc isome ic o ms defined by he cis/ ans disposi ion o he ge myl and phosphine ac oss he pla inum cen e we e disclosed and cha ac e ized by spec oscopicmeans andX- aydi ac ions udies.We o esee ha his flexibili y will be o ele ance o he applica ion o his and o he ela ed low-coo dina e coope a i e sys ems in ca alysis. Indeed, we al eady in es iga ed i s ca aly ic po en ial in he hyd odehalogena ion o alipha ic and a oma ic halides unde he mal and pho ochemical condi ions. Unde mild dihyd ogen p essu e (1 ba ), good con e sions and selec i i y we e eco ded e en o ine alkyl chlo ides. The p o- posed mechanism in ol es he ac i e pa icipa ion o he wo ac i e si es, which unde sco e he po en ial o s ill unde de eloped sys ems ha pa ne low- alen ansi ion and main g oup me als in pa icula ly low-coo dina ion en i onmen s, a esea ch a enue ha we a e cu en ly pu suing in ou labo a o ies. Me hods Gene al conside a ions All p epa a ions and manipula ions we e pe o med by using s anda d Schlenk and glo ebox echniques, unde an a mosphe e o a gon and o high pu i y ni ogen, espec i ely. All sol en s we e d ied, s o ed o e 4 Å molecula sie es, and degassed p io o use. Toluene (C 7 H 8 ), THF (C 4 H 8 O), and n-pen ane (C 5 H 12 ) we e dis illed unde ni ogen o e sodium. [D 8 ]-THF and C 6 D 6 we ed iedo e sodium and dis illedunde a gon. All o he eagen s we e used as ecei ed om comme cial supplie s. Solu ion NMR spec a we e eco ded wi h B uke AVANCE NEO-300, AVANCE NEO-400, AVANCE III-400, and AVANCE NEO-500 spec ome e s. Spec a we e e e enced o ex e nal SiMe 4 (δ: 0 ppm) by using he esidual p o on sol en peaks as in e nal s anda ds (1H NMR expe imen s), o he cha ac e is ic esonances o he sol en nuclei (13CNMRexpe imen s),while31P was e e enced o H 3 PO 4 .The 1Hand13C signals we e assigned by means o 2D HSQC and HMBC expe imen s. The X- ay di ac ion s uc u al cha ac e iza ion o compounds 2 *, 3, and 7a is collec ed in Supplemen a y Da a 2, Sup- plemen a y Da a 3, and Supplemen a y Da a 4, espec i ely. Syn hesis o new compounds The syn hesis and spec oscopic cha ac e iza ion o compounds 1, 2 , 3, 5, and 7a is desc ibed he ein, while de ails o o he compounds and p ecu so s a e desc ibed in he Supplemen a y In o ma ion. Com- pound 1. In he Glo ebox, a J-Young NMR ube was loaded wi h [A Dipp2GeCl] 2 (16 mg, 0.016 mmol) and [(PMe 2 A Dipp2)P (TBE)] (24 mg, 0.032mmol). Then he solids we e solubilized in 0.5mL o C 6 D 6 o yield an in ense ed solu ion o compound 1(>99% NMR yield). A emp s o isola e i om he eac ion mix u e, e en a la ge scales, p o ed unsuccess ul due o high ins abili y. 1H NMR (400 MHz, C 6 D 6 , Fig. 8 | P oposed ca aly ic cycle. P oposed mechanism o he hyd o- dehalogena ion o NpB ca alyzed by 1based on expe imen al and compu a ional in es iga ions. Calcula ions pe o med a he DFT PCM-ZORA-B3PW91-D3BJ/de 2- TZVP + SARC-ZORA-TZVP(P )//PCM-BP86-D3BJ/de 2-SVP le el o heo y. (iP = isop opyl; Dipp = 2,6-(C 6 H 3 -2,6-iP 2 ) 2 ;A Dipp =C 6 H 3 -2,6-(C 6 H 3 -2,6-iP 2 ) 2 ; HMDS = hexame hyldisilazane; Np = neopen yl). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 8 298 K): δ7.22–7.17 (o e lapping signals, 4H, CH), 7.14–7.07 (o e - lapping signals, 9H, CH), 6.92–6.88 (o e lapping signals, 4H, CH), 6.69 (b , 1H, CH), 3.09 (sep , J H-H =6.6Hz, 4H, CH(CH 3 ) 2 ), 2.33 (b , 4H, CH(CH 3 ) 2 ), 1.38 (d, J H-H = 6.6 Hz, 12H, CH(CH 3 ) 2 ), 1.33 (o e lapping signals, 18H, CH(CH 3 ) 2 +PMe 2 ), 1.05 (d, J H-H =6.6Hz,12H,CH(CH 3 ) 2 ), 0.89 (d, J H-H =6.6Hz,12H,CH(CH 3 ) 2 ). 31P{1H} NMR (161.98 MHz, C 6 D 6 , 298 K): δ17.9 (s, 1J PP =5376Hz). 13C{1H} NMR (100.63 MHz, C 6 D 6 , 298 K): δ160.7 (d, J C-P = 18 Hz, Cq), 147.8 (Cq), 147.3 (d, J C-P =11Hz,Cq), 143.0 (d, J C-P = 3 Hz, Cq), 141.9 (d, J C-P = 34 Hz, Cq), 137.9 (Cq), 131.6 (d, J C-P = 7 Hz, CH), 129.7 (CH), 129.2 (CH), 128.6 (d, J C-P =3Hz,CH),128.3 (CH), 128.0 (CH), 123.7 (CH), 122.5 (CH), 31.6 (b , CH(CH 3 ) 2 ), 30.8 (CH(CH 3 ) 2 ),25.8(CH(CH 3 ) 2 ), 25.2 (CH(CH 3 ) 2 ), 23.3 (CH(CH 3 ) 2 ), 22.9 (b , CH(CH 3 ) 2 ), 19.9 (d, J C-P =28Hz, PMe 2 ). Compound 2 and 2c.In he Glo ebox, a J-Young NMR ube was loaded wi h [A Dipp2GeCl] 2 (16 mg, 0.016 mmol) and [(PMe 2 A Dipp2)P (TBE)] (24 mg, 0.032 mmol). Then he solids we e solubilized in 0.5 mL o C 6 D 6 , eeze-pumped o emo e he ni ogen gas, and filled wi h 0.5 ba o H 2 , which esul ed in immedia e anish o he in ense ed colo owa ds a pale-yellow solu ion o a mix u e o wo isome s o complex 2(73% 2 and 27% 2c; NMR spec oscopic yield). Signals o 2 :1H NMR (400 MHz, C 6 D 6 , 298 K): δ7.28 ( , J H-H = 7.5Hz, 2H, CH), 7.24-7.20 (o e lapping signals, 7H,CH),7.13–7.11 (o e lapping signals, 4H, CH), 6.97 (d, J H-H = 7.5 Hz, 1H, CH), 6.88 ( , J H-H =7.5Hz,1H,CH),6.80(m,2H,CH),6.41(m,1H,CH), 3.50 (dd, J H-P =30.7,J H-H = 5.2 Hz, 1H, Ge-H), 3.21 (sep , J H-H =6.7Hz,2H, CH(CH 3 ) 2 ), 3.10 (sep , J H-H = 6.7 Hz, 1H, CH(CH 3 ) 2 ), 2.96 (sep , J H-H = 6.7 Hz, 1H, CH(CH 3 ) 2 ), 2.35 (m, 2H, CH(CH 3 ) 2 ), 2.12 (sep , J H-H = 6.7 Hz, 1H, CH(CH 3 ) 2 ), 1.47 (o e lapping signals, 6H, CH(CH 3 ) 2 (3H) + PMe 2 (3H)), 1.42-1.33 (m, 21H, CH(CH 3 ) 2 (18H) + PMe 2 (3H)), 1.12–1.08 (o e lapping signals, 15H, CH(CH 3 ) 2 ), 0.80 (o e lapping sig- nals, 12H, CH(CH 3 ) 2 ), −15.7 ( , J H-P =5.2,J H-H = 5.2, J H-P =1608Hz,1H,P - H). 31P{1H} NMR (161.98 MHz, C 6 D 6 ,298K):δ21.9 (s, 1J PP =2671Hz). 13C{1H} NMR (100.63 MHz, C 6 D 6 ,298K):δ149.4 (Cq), 147.6 (Cq), 147.5 (Cq), 147.0 (d, J C-P = 12 Hz, Cq), 146.7 (Cq), 146.4 (Cq), 146.2 (Cq), 142.9 (Cq), 141.0 (Cq), 140.5 (d, J C-P =13Hz,Cq),136.7(d,J C-P = 7 Hz, Cq), 132.2 (CH), 132.1 (CH), 132.0 (CH), 130.3 (CH), 130.2 (CH), 129.7 (CH), 129.4 (CH), 129.2 (CH), 129.1 (CH), 128.7 (CH), 128.4 (CH), 127.0 (CH), 126.4 (CH), 126.2 (CH), 125.3 (CH), 124.5 (CH), 123.0 (CH), 122.8 (CH), 122.7 (CH), 122.6 (CH), 122.4 (CH), 122.2 (CH), 122.1 (CH), 122.0 (CH), 31.6 (CH(CH 3 ) 2 ), 31.0 (CH(CH 3 ) 2 ), 30.9 (CH(CH 3 ) 2 ), 30.7 (CH(CH 3 ) 2 ), 30.6 (CH(CH 3 ) 2 ), 30.5 (CH(CH 3 ) 2 ), 25.7 (CH(CH 3 ) 2 ), 25.6 (CH(CH 3 ) 2 ), 25.5 (CH(CH 3 ) 2 ), 25.4 (CH(CH 3 ) 2 ), 25.2 (CH(CH 3 ) 2 ), 24.0 (CH(CH 3 ) 2 ), 23.8 (CH(CH 3 ) 2 ), 23.4 (CH(CH 3 ) 2 ), 23.2 (CH(CH 3 ) 2 ), 21.1 (CH(CH 3 ) 2 ), 17.5 (d, J C-P =12Hz,PMe 2 ), 16.7(d, J C-P = 13 Hz, PMe 2 ). Selec ed signals o 2c:1H NMR (400 MHz, C 6 D 6 ,298K):5.90(dd,J H-P =10.9,J H-H = 2.3 Hz, 1H, Ge- H), −5.6 (d, J H-P = 178.0, J H-P = 341.6 Hz, 1H, P -H). 31P{1H} NMR (161.98 MHz, C 6 D 6 ,298K):δ25.6 (s). Compound 3. In he Glo ebox, a J-Young NMR ube was loaded wi h [A Dipp2GeCl] 2 (16 mg, 0.016 mmol) and [(PMe 2 A Dipp2)P (TBE)] (24 mg, 0.032 mmol). Then he solids we e solubilized in 0.5 mL o C 6 D 6 yielding an in ense ed solu ion o 1.Then 5 equi alen s o H 2 Owe eadded(3µL, 0.16 mmol) leading o a pale- yellow solu ion o he complex 3(>99% NMR yield). A small c op o sui able c ys als o X- ay analysis was g own om slow di usion o pen ane in o i s benzene solu ion (4 mg, 11%). 1H NMR (400 MHz, C 6 D 6 , 298 K): δ7.31 (d, J H-H = 7.6 Hz, 1H, CH), 7.25–7.22 (m, 3H, CH), 7.20-7.18 (m, 3H, CH), 7.16-7.14 (b , 2H, CH), 7.12–7.10 (m, 2H, CH), 7.05-7.02 (m, 2H, CH), 6.99 (dd, J H-H = 7.6, J H-H = 3.2 Hz, 2H, CH), 6.87 (d, J H-H =7.6Hz, 1H,CH),6.80( d,J H-H =7.6Hz,J H-P = 2.2, 1H), 6.72 ( , J H-H =7.6Hz,1H, CH), 6.36 (b d, J H-H = 7.6 Hz, 1H, CH), 3.26 (sep , J H-H = 6.7 Hz, 4H, CH(CH 3 ) 2 ), 3.02 (sep , J H-H =6.7Hz, 4H, CH(CH 3 ) 2 ), 2.36 (m, 4H, CH(CH 3 ) 2 ), 1.67 (d, J H-P =5.3Hz, 3H, PMe 2 ), 1.64 (d, J H-P = 5.3 Hz, 3H, PMe 2 ), 1.45 (d, J H-H = 6.7 Hz, 9H, CH(CH 3 ) 2 ), 1.35 (d, J H-H = 6.7 Hz, 6H, CH(CH 3 ) 2 ), 1.07 (d, J H-H =6.7Hz,12H,CH(CH 3 ) 2 ), 1.02 (d, J H-H =6.7Hz, 3H, CH(CH 3 ) 2 ), 1.00 (d, J H-H = 6.7 Hz, 3H, CH(CH 3 ) 2 ), 0.98 (d, J H-H = 6.7 Hz, 3H, CH(CH 3 ) 2 ), 0.85 (d, J H-H =6.7Hz,3H,CH(CH 3 ) 2 ), 0.81 (d, J H-H = 6.7 Hz, 3H, CH(CH 3 ) 2 ), 0.80 (d, J H-H = 6.7 Hz, 3H, CH(CH 3 ) 2 ), 0.77 (d, J H-H = 6.7 Hz, 3H, CH(CH 3 ) 2 ), −7.45 (d, J H-P = 180, J H-P =297Hz, 1H, P -H). 31P{1H} NMR (161.98 MHz, C 6 D 6 ,298K):δ29.6 (1J PP =2125Hz).13C{1H} NMR (100.63 MHz, C 6 D 6 ,298K):δ147.4 (Cq), 147.1 (Cq), 146.8 (Cq), 146.7 (Cq), 146.5 (Cq), 145.8 (d, J C-P =13Hz,Cq), 145.6 (Cq), 144.0 (Cq), 143.0 (Cq), 140.9 (d, J C-P = 34 Hz, Cq), 139.7 (Cq), 138.3 (Cq), 137 (d, J C-P = 7 Hz, Cq), 132.2 (CH), 131.5 (CH), 131.4 (CH), 131.3 (CH), 129.9 (CH), 129.7 (CH), 129.5 (CH), 129.1 (CH), 129.0 (CH), 128.6 (d, J C-P = 6 Hz, CH), 126.8 (CH), 125.5 (CH), 123.0 (CH), 122.9 (CH), 122.8 (CH), 122.7 (CH), 122.5 (CH), 30.9 (CH(CH 3 ) 2 ), 30.8 (CH(CH 3 ) 2 ), 30.7 (CH(CH 3 ) 2 ), 26.0 (CH(CH 3 ) 2 ), 25.8 (CH(CH 3 ) 2 ), 25.5 (CH(CH 3 ) 2 ), 25.4 (CH(CH 3 ) 2 ), 25.3 (CH(CH 3 ) 2 ), 24.1 (CH(CH 3 ) 2 ), 24.0 (CH(CH 3 ) 2 ), 23.4 (CH(CH 3 ) 2 ), 22.3 (CH(CH 3 ) 2 ), 15.5 (d, J C-P =27Hz, PMe 2 ), 15.2 (d, J C-P =27Hz,PMe 2 ). Compound 5. In he Glo ebox, a J-Young NMR ube was loaded wi h [A Dipp2GeCl] 2 (16 mg, 0.016 mmol) and [(PMe 2 A Dipp2) P (TBE)] (24 mg, 0.032mmol). Then he solids we e solubilized in 0.5 mL o C 6 D 6 , eeze-pumped o emo e he a gon gas, and filled wi h 0.5 ba o NH 3 . The in ense ed colo apidly anished o o m a pale-yellow solu ion o complex 5(a ound 95%spec oscopic yield). 1H NMR (400 MHz, C 6 D 6 ,298K):δ7.20–7.13 (o e lapping signals, 7H, CH), 7.11–7.09 (o e lapping signals, 5H, CH), 7.05 ( , J H-H = 7.2 Hz, 4H, CH), 6.98–6.92 (o e lapping signals, 3H, CH), 3.25 (sep , J H-H = 6.7 Hz, 1H, CH(CH 3 ) 2 ), 3.18 (sep , J H-H = 6.7 Hz, 2H, CH(CH 3 ) 2 ), 2.94 (m, 1H, CH(CH 3 ) 2 ), 2.83 (sep , J H-H = 6.7 Hz, 2H, CH(CH 3 ) 2 ), 2.74 (sep , J H-H = 6.7 Hz, 2H, CH(CH 3 ) 2 ), 1.48 (m, 12H, CH(CH 3 ) 2 ), 1.38 (d, J H-H = 6.7 Hz, 6H, CH(CH 3 ) 2 ), 1.27 (d, J H-H = 6.7 Hz, 6H, CH(CH 3 ) 2 ), 1.14–1.06 (o e lapping signals, 1H, CH(CH 3 ) 2 (6H) + PMe 2 (6H)), 1.01–0.98 (o e lapping signals, 6H, CH(CH 3 ) 2 ), 0.87–0.83 (o e lapping signals, 12H, CH(CH 3 ) 2 ), −18.06 (d, J H-P =16, J H-P =1092Hz, 1H, P -H) 31P{1H} NMR (161.98 MHz, C 6 D 6 ,298K):δ−11.2 (1J PP =2429Hz).13C{1H} NMR (100.63 MHz, C 6 D 6 ,298K):δ148.1 (Cq), 148.0 (Cq), 147.5 (Cq), 147.0 (d, J C-P = 25 Hz, Cq), 146.6 (Cq), 145.1 (Cq), 143.2 (d, J C-P =8Hz, Cq), 142.2 (Cq), 140.0 (Cq), 132.9 (d, J C-P = 7 Hz, CH), 130.3 (CH), 130.0 (CH), 126.7 (CH), 126.2 (CH), 123.5 (CH), 123.0 (CH), 122.7 (CH), 122.6 (CH), 121.9 (CH), 31.2 (CH(CH 3 ) 2 ), 31.0 (CH(CH 3 ) 2 ), 30.9 (CH(CH 3 ) 2 ), 30.7 (CH(CH 3 ) 2 ), 25.6 (CH(CH 3 ) 2 ), 25.5 (CH(CH 3 ) 2 ), 25.3 (CH(CH 3 ) 2 ), 23.9 (CH(CH 3 ) 2 ), 23.7 (CH(CH 3 ) 2 ), 23.2 (CH(CH 3 ) 2 ), 22.4 (CH(CH 3 ) 2 ), 14.0 (d, J C-P =15Hz,PMe 2 ), 13.8 (d, J C-P =9Hz,PMe 2 ). Compound 7b.In he Glo ebox, a J-Young NMR ube was loaded wi h [A Dipp2GeCl] 2 (16 mg, 0.016 mmol) and [(PMe 2 A Dipp2)P (TBE)] (24 mg, 0.032 mmol). Then he solids we e solubilized in 0.5 mL o C 6 D 6 yielding an in ense ed solu ion o 1. Then 2 equi alen s o phenylace ylene we e added (8 µL, 0.064 mmol) leading oa pale-yellow solu ion o he complex7b, which o med in a ound 95% spec oscopic yield. A small c op o sui- able c ys als o X- ay analysis was g own om slow di usion o pen ane in o i s benzene solu ion (5 mg, 11%). 1H NMR (400 MHz, C 6 D 6 , 298 K): δ7.47 ( , J H-H = 7.7Hz, 2H, CH), 7.40 (b , 2H, CH), 7.27 (b d, J H-H = 7.1 Hz, 6H, CH), 7.20−7.15 (o e lapping signals, 6H, CH), 7.09 ( , J H-H =7.1Hz,3H,CH),7.03–6.95 (o e lapping signals, 3H, CH), 6.89 (b d, J H-H = 7.1Hz, 5H, CH), 6.76 ( , J H-H = 7.7 Hz, 1H, CH), 6.60 (b , 2H, PhC=CH), 3.12 (sep , J H-H =6.6Hz, 2H, CH(CH 3 ) 2 ), 2.98 (m, 2H, CH(CH 3 ) 2 ), 2.64 (sep , J H-H = 6.6 Hz, 2H, CH(CH 3 ) 2 ), 2.54 (m, 2H, CH(CH 3 ) 2 ), 1.56 (d, J H-H = 6.6 Hz, 6H, CH(CH 3 ) 2 ), 1.37−1.27 (o e lapping signals, 12H, CH(CH 3 ) 2 ), 1.16 (b , 9H, CH(CH 3 ) 2 ), 1.02 (b , 12H, CH(CH 3 ) 2 ), 0.84 (o e lapping signals, 6H, CH(CH 3 ) 2 (3H) + PMe 2 (3H)), 0.68 (b , 6H, CH(CH 3 ) 2 ), 0.57 (d, J H-P = 7.8Hz, 3H, PMe 2 ). 31P{1H} NMR (161.98 MHz, C 6 D 6 ,298K):δ13.5 (1J PP =2184Hz). 13C{1H} NMR (100.63 MHz, C 6 D 6 ,298K):δ148.3 (Cq), 147.7 (d, J C-P =18Hz,Cq), 147.0 (Cq), 146.4 (Cq), 146.4 (Cq), 144.9 (d, J C-P = 14 Hz, Cq), 141.5 (Cq), 140.4 (Cq), 139.0 (d, J C-P = 37 Hz, Cq), 132.5 (d, J C-P =7Hz, PhC=CH), 132.0 (CH), 130.4 (CH), 129.6 (CH), 128.4 (CH), 128.2 (CH), 126.3 (CH), 122.7 (CH), 125.0 (CH), 123.4 (CH), 123.0 (CH), 122.9 (CH), 31.6 (CH(CH 3 ) 2 ), 31.3 (CH(CH 3 ) 2 ), 30.8 (CH(CH 3 ) 2 ), 30.6 (CH(CH 3 ) 2 ), 25.8 (CH(CH 3 ) 2 ), 25.7 (CH(CH 3 ) 2 ), 25.5 (CH(CH 3 ) 2 ), 25.1 (CH(CH 3 ) 2 ), 23.4 (CH(CH 3 ) 2 ), 22.7 (CH(CH 3 ) 2 ), 22.3 (CH(CH 3 ) 2 ), 13.9 (d, J C-P =8Hz,PMe 2 ). A icle h ps://doi.o g/10.1038/s41467-024-53940-9 Na u e Communica ions | (2024) 15:9656 9