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
).
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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.
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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 .
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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).
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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