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Expe imen al and compu a ional in es iga ion on he o ma ion pa hway o
[RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) om [RuCl2(CO)3]2 and ERR′
© The Royal Socie y o Chemis y 2022
Published e sion
Taimis o, Ma jaana; Bajo ek, Tom; Rau iainen, J. Mikko; Pakkanen, Tapani A.;
Oilunkaniemi, Raija; Lai inen, Ris o S.
Taimis o, M., Bajo ek, T., Rau iainen, J. M., Pakkanen, T. A., Oilunkaniemi, R., & Lai inen, R. S.
(2022). Expe imen al and compu a ional in es iga ion on he o ma ion pa hway o
[RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) om [RuCl2(CO)3]2 and ERR′. Dal on
T ansac ions, 51(31), 11747-11757. h ps://doi.o g/10.1039/D2DT02018A
2022
Dal on
T ansac ions
PAPER
Ci e his: DOI: 10.1039/d2d 02018a
Recei ed 25 h June 2022,
Accep ed 12 h July 2022
DOI: 10.1039/d2d 02018a
sc.li/dal on
Expe imen al and compu a ional in es iga ion on
he o ma ion pa hway o [RuCl
2
(CO)
2
(ERR’)
2
]
(E = S, Se, Te; R, R’= Me, Ph) om [RuCl
2
(CO)
3
]
2
and ERR’†
Ma jaana Taimis o,
a
Tom Bajo ek,‡
a
J. Mikko Rau iainen,
b
Tapani A. Pakkanen,
a
Raija Oilunkaniemi *
a
and Ris o S. Lai inen *
a
The pa hways o he o ma ion o he se ies o [RuCl
2
(CO)
2
(ERR’)
2
] (E = S, Se, Te; R, R’= Me, Ph) com-
plexes om [RuCl
2
(CO)
3
]
2
and ERR’ha e been explo ed expe imen ally in THF and CH
2
Cl
2
, and compu a-
ionally by PBE0-D3/de 2-TZVP calcula ions. The end-p oduc s and some eac ion in e media es ha e
been isola ed and iden ified by NMR spec oscopy, and hei c ys al s uc u es ha e been de e mined by
X- ay diff ac ion. The ela i e s abili ies o he [RuCl
2
(CO)
2
(ERR’)
2
] isome s ollow he o de cc >ccc > cc
> ≈c c ( he e ms c/ e e o cis/ ans a angemen o he ligands in he o de o Cl, CO, and ERR’).
The yields we e a he simila in bo h sol en s, bu he eac ions we e significan ly as e in THF han in
CH
2
Cl
2
. The highes yields we e obse ed o he ellu oe he complexes, and he yields dec eased wi h
ligh e chalcogenoe he s. PBE0-D3/de 2-TZVP calcula ions indica ed ha he eac ion pa h is indepen-
den o he na u e o he sol en . The subs i u ion o one CO ligand o he in e media e
[RuCl
2
(CO)
3
(ERR’)] by he second ERR’shows he highes ac i a ion ba ie and is he a e-de e mining
s ep in all eac ions. The obse ed as e eac ion a e in THF han in CH
2
Cl
2
upon eflux can he e o e be
explained by he highe boiling poin o THF. A oom empe a u e he eac ions in bo h sol en s p oceed
equally slowly. When he eac ion is ca ied ou in THF, he o ma ion o [RuCl
2
(CO)
3
(THF)] is also
obse ed, and he eac ion may p oceed wi h he subs i u ion o THF by ERR’. The o ma ion o he THF
complex, howe e , is no necessa y o he dissocia ion o he [RuCl
2
(CO)
3
]
2
. The mal ene gy a oom
empe a u e is sufficien o clea e one o he b idging Ru–Cl bonds. The in e media e hus o med unde -
goes a acile eac ion wi h ERR’. This mechanism is iable also in non-coo dina ing CH
2
Cl
2
.
In oduc ion
Ca bon monoxide eleasing molecules (CORMs) ha e u ned
ou o be impo an in sa e applica ions o CO in he apeu ics.
Sui able molecules include o ganome allic complexes, alde-
hydes, cyclic dike ones, and ca boxylic acids, among o he s
( o some selec ed examples o ecen e iews, see e . 1).
While [RuCl
2
(CO)
3
]
2
(CORM-2) is a use ul ca bon monoxide
eleasing compound, i is also a con enien eagen in he
p epa a ion o mononuclea complexes o u henium ( o he
syn heses and s uc u al cha ac e iza ion o selec ed com-
plexes wi h diffe en non-me allic dono a oms du ing he pas
en yea s, see e . 2). The main p oduc s in hese eac ions
wi h monoden a e ligands a e [RuCl
2
(CO)
3
L]
2a,c,e,g,h
and
[RuCl
2
(CO)
2
L
2
]
2a–c,g,l
(see Cha 1).
The ac-isome is mos common o [RuCl
2
(CO)
3
L], as exem-
pli ied by he ecen X- ay s uc u al de e mina ions,
2c,g,h
and
also indica ed by NMR spec oscopy.
2a,c,e,g,h
In case o
[RuCl
2
(CO)
2
L
2
], he cc isome s a e p edominan ,
2a,b,g,l
hough
he cc-isome has also been epo ed.
2c
In case o polyden a e
chela ing ligands, he ac ual isome depends on he s e eoche-
mical equi emen s by he ligand.
2d, ,i,j
The o ma ion o [RuCl
2
(CO)
3
L] and [RuCl
2
(CO)
2
L
2
] is gen-
e ally hough o be sequen ial wi h he ini ial in e ac ion
be ween he incoming ligand and he u henium cen e
leading o he symme ic clea age o he b idging chlo ido
ligands
3
(see Scheme 1). The second pa o he eac ion is he
†Elec onic supplemen a y in o ma ion (ESI) a ailable: Syn he ic de ails, c ys al
s uc u e de e mina ions o 2
cc
,4
cc
,6
cc
,8
cc
,10, and 11, en a i e molecula
s uc u e o 8
cc
, assignmen o NMR spec a, compu a ional esul s. CCDC
2152613–2152617 and 2152619. Fo ESI and c ys allog aphic da a in CIF o o he
elec onic o ma see DOI: h ps://doi.o g/10.1039/d2d 02018a
‡P esen add ess: Nu iAg L d, 62 A ow Rd To on o, ON, M9M 2L8 Canada.
a
Labo a o y o Ino ganic Chemis y, En i onmen al and Chemical Enginee ing,
Uni e si y o Oulu, P.O. Box 3000, 90014 Oulu, Finland.
E-mail: [email p o ec ed]
b
Depa men o Chemis y and Nanoscience Cen e , Uni e si y o Jy äskylä, P.O. Box
35, 40014 Jy äskylä, Finland
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subs i u ion o CO by he incoming ligand in he mononuclea
complexes hus o med.
The coo dina ion o a sol en molecule Sol o
[RuCl
2
(CO)
3
]
2
has been sugges ed o be an ini ial s ep in he
eac ion esul ing in he o ma ion o mononuclea ac-
[RuCl
2
(CO)
3
(Sol )]. The ligand subs i u ion o Sol by he
incoming ligand L leads o ac-[RuCl
2
(CO)
3
L]. The subs i u ion
o CO by he second ligand affo ds he inal p oduc (see
Scheme 1). This is exempli ied by he eac ions o
[RuCl
2
(CO)
3
]
2
wi h bipy idine ligands in diffe en sol en s.
3
While his app oach is logical and is gene ally accep ed, he e
is no di ec expe imen al o compu a ional e idence ha he
ligand subs i u ion in [RuCl
2
(CO)
3
]
2
eally ollows his
pa hway. The cu en con ibu ion add esses his issue by
explo ing he eac ion o [RuCl
2
(CO)
3
]
2
wi h chalcogenoe he s
ERR′(E = S, Se, Te; R, R′= Me, Ph).
Mononuclea chalcogenoe he complexes o u henium
ha e long been known ( o ea ly li e a u e, see e iews in e .
4). Du ing he las h ee decades hese complexes ha e
a ac ed mo e a en ion, which is cen e ed on he ligand
chemis y o seleno- and ellu oe he s in addi ion o hioe he s
( o mo e ecen e iews, see e . 5). Hiebe and John
6
explo ed
al eady in 1970s he isome ism o [RuCl
2
(CO)
2
(ERR′)
2
](E=S,
Se, Te; R, R′= a numbe o alkyl o a yl g oups) by eco ding
he dipole momen s, IR spec a, and
1
H NMR spec a o he
complexes o med in diffe en eac ions. John
6b
in e ed ha
he main isome in each complex is he cc (see Cha 1). The
la e c ys al s uc u e de e mina ions o [RuCl
2
(CO)
2
(SPh
2
)
2
],
7
[RuCl
2
(CO)
2
(TePh
2
)
2
],
8
and [RuCl
2
(CO)
2
{Te(CH
2
SiMe
3
)
2
}
2
]
9
ha e con i med ha in he solid s a e, all h ee complexes
indeed exis as cc -isome s.
As pa o ou pu sui o explo e he o ma ion mechanism
o [RuCl
2
(CO)
2
L
2
] complexes we ha e in es iga ed in his con-
ibu ion he o ma ion, s e eochemis y, and isome ism o
[RuCl
2
(CO)
2
(ERR′)
2
] (E = S, Se, Te; R, R′= Me, Ph) complexes
(see Table 1). We epo he c ys al s uc u es o 2
cc
,4
cc
, and
6
cc
, as well as he isola ion and cha ac e iza ion o
[RuCl
2
(CO)
3
(SeMe
2
)] (10) and [RuCl
2
(CO)
3
(SeMePh)] (11) com-
plexes ha a e po en ial in e media e p oduc s along he eac-
ion pa h. The eac ion pa hway has been explo ed by PBE0-
D3/de 2-TZVP calcula ions.
Expe imen al
Gene al
The syn heses o SeMePh and TeMePh we e ca ied ou unde
an ine a mosphe e by using Schlenk echniques. The eac-
ions wi h [RuCl
2
(CO)
3
]
2
we e ca ied ou in ai . [RuCl
2
(CO)
3
]
2
Cha 1 Possible isome s o [RuCl
2
(CO)
3
L], [RuCl
2
(CO)
2
L
2
], and
[RuCl
2
(CO)L
3
]. The no a ion o he isome s o [RuCl
2
(CO)
2
L
2
]: cc =
cis(Cl), cis(CO), ans(L); ccc =cis(Cl), cis(CO), cis(L); c c =cis(Cl),
ans(CO), cis(L); = ans(Cl), ans(CO), ans(L); cc = ans(Cl),
cis(CO), cis(L).
Scheme 1 Fo ma ion o ac-[RuCl
2
(CO)
3
L] and cc -[RuCl
2
(CO)
2
L
2
] om [RuCl
2
(CO)
3
]
2
.
Table 1 The designa ion o he [RuCl
2
(CO)
2
(ERR’)
2
] (E = S, Se, Te; R, R’= Me, Ph) isome s (see Cha 1)
[RuCl
2
(CO)
2
(SMe
2
)
2
]1
cc
,1
ccc
,1
cc
,1
,1
c c
[RuCl
2
(CO)
2
(SMePh)
2
]2
cc
,2
ccc
,2
cc
,2
,2
c c
[RuCl
2
(CO)
2
(SPh
2
)
2
]3
cc
,3
ccc
,3
cc
,3
,3
c c
[RuCl
2
(CO)
2
(SeMe
2
)
2
]4
cc
,4
ccc
,4
cc
,4
,4
c c
[RuCl
2
(CO)
2
(SeMePh)
2
]5
cc
,5
ccc
,5
cc
,5
,5
c c
[RuCl
2
(CO)
2
(SePh
2
)
2
]6
cc
,6
ccc
,6
cc
,6
,6
c c
[RuCl
2
(CO)
2
(TeMe
2
)
2
]7
cc
,7
ccc
,7
cc
,7
,7
c c
[RuCl
2
(CO)
2
(TeMePh)
2
]8
cc
,8
ccc
,8
cc
,8
,8
c c
[RuCl
2
(CO)
2
(TePh
2
)
2
]9
cc
,9
ccc
,9
cc
,9
,9
c c
Pape Dal on T ansac ions
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(Johnson Ma hey), Te
2
Ph
2
(Ald ich), Se
2
Ph
2
(Ald ich), SMePh
(Fluka Chemicals), me hyl iodide (Bake ), SeMe
2
(Fluka
Chemicals), NaBH
4
(Me ck), and n-hexane (Kebolab) we e used
as pu chased. Te ahyd o u an (Lab-Scan) and die hyl e he
(Lab-Scan) we e d ied o e Na/benzophenone and dichlo o-
me hane (Lab-Scan) o e P
4
O
10
. Me hanol (Fishe Sci. In . Co)
was deoxygena ed wi h a gon p io o use.
NMR spec oscopy
The
13
C{
1
H},
77
Se, and
125
Te NMR spec a we e eco ded a
oom empe a u e on a B uke DPX 400 spec ome e ope a -
ing a 100.61, 76.31, and 126.24 MHz, espec i ely. The espec -
i e spec al wid hs we e 25.06–26.04, 30.18–53.33, and
37.88–63.49 kHz. The pulse wid h was 4.0 μs o
13
C, 6.7 μs o
77
Se, and 10.0 μs o
125
Te. The
13
C{
1
H} NMR spec a we e
e e enced o he sol en esonance and a e epo ed ela i e o
Me
4
Si. Sa u a ed solu ions o SeO
2
(aq) and H
6
TeO
6
(aq) we e
used as ex e nal s anda ds o
77
Se and
125
Te chemical shi s.
Chemical shi s (ppm) a e epo ed ela i e o nea SeMe
2
and
TeMe
2
[δ(SeMe
2
)=δ(SeO
2
) + 1302.6 ( e . 10) and δ(TeMe
2
)=
δ(H
6
TeO
6
) + 710.9 ( e . 11)].
X- ay diff ac ion
Diff ac ion da a o 2
cc
,4
cc
,6
cc
,10, and 11 we e collec ed on a
B uke Nonius Kappa-CCD diff ac ome e using g aphi e
monoch oma ed MoK
α
adia ion (λ= 0.71073 Å; 55 kV, 25 mA).
C ys al da a and he de ails o he s uc u e de e mina ions a e
gi en in Table S1 in ESI.†
S uc u es we e sol ed by di ec me hods using
SHELXS-2016 and e ined using SHELXL-2016.
12
A e he ull-
ma ix leas -squa es e inemen o he non-hyd ogen a oms wi h
aniso opic he mal pa ame e s, he hyd ogen a oms we e placed
in calcula ed posi ions in he a oma ic ings (C–H = 0.95 Å) and
in he CH
3
g oups (C–H = 0.98 Å). The sca e ing ac o s o he
neu al a oms we e hose inco po a ed wi h he p og ams.
Quali y o he ob ained c ys als o 8
cc
enabled only an
app oxima e e inemen o he s uc u e. The e inemen
equi ed cons aining he he mal pa ame e s o all ca bon
a oms o be equal. This complex and he app oxima e me ical
da a o bond pa ame e s a e shown in ESI (Fig. S1†), since he
accu acy o he c ys al s uc u e de e mina ion was sufficien
o he iden i ica ion o he species and he e o e allowed he
unambiguous assignmen o he
125
Te NMR esonance.
P epa a ion o SeMePh and TeMePh
Diphenyl diselenide o di ellu ide (0.507 g, 1.64 mmol and
0.658 g, 1.61 mmol, espec i ely) was dissol ed in 25 mL o
THF, and a solu ion o NaBH
4
in MeOH was added d opwise a
0 °C un il he solu ion u ned colou less. Me hyl iodide
(0.200 mL, 3.20 mmol) was added, and he solu ion was
s i ed a oom empe a u e o wo hou s. The eac ion
mix u e was pou ed in o wa e and ex ac ed wi h die hyl e he
in se e al po ions. The combined o ganic laye s we e d ied on
MgSO
4
. E apo a ion o he sol en affo ded SeMePh as a ligh -
yellow oil (0.454 g, yield 83%) and TeMePh as a yellow oil
(0.471 g, yield 67%). SeMePh: NMR (δ, ppm) (CDCl
3
):
13
C{
1
H}
6.7 (s, CH
3
), 125.8, 128.9, 129.9, 131.9;
77
Se 197 (c . li . 197 ( e .
13)). TeMePh: NMR (δ, ppm) (CDCl
3
):
13
C{
1
H} −17.2 (s, CH
3
),
112.3, 126.9, 129.0, 136.3;
125
Te 328 (c . li . 329 ( e . 14)).
Gene al p ocedu e o he p epa a ion o [RuCl
2
(CO)
2
(ERR′)
2
]
(E = S, Se, Te; R, R′= Me, Ph)
A ypical syn hesis was ca ied ou by dissol ing ERR′(E = S,
Se, Te; R, R′= Me, Ph) in 5 mL o CH
2
Cl
2
o THF and adding he
esul ing solu ion d opwise o a suspension o [RuCl
2
(CO)
3
]
2
in
15 mL o he same sol en . The mix u e was e luxed un il a
clea solu ion was ob ained ( ypical imes we e 50–100 h in
CH
2
Cl
2
and 5–10 h in THF). The solu ion was e apo a ed o hal
o he o iginal olume and hexane was added. The p ecipi a e
was sepa a ed by il a ion and e-c ys allized om CH
2
Cl
2
/
hexane a +3 °C. In some eac ions, wo c ops o c ys als we e
o med. They we e manually sepa a ed unde he mic oscope.
The quan i a i e in o ma ion o he syn heses, as well as he
assignmen o he NMR spec a and he iden i ica ion o he
complexes a e gi en in sec ions 1 and 4 in ESI.†
Compu a ional de ails
All s uc u es we e op imized using Gaussian 16 p og am
package,
15
PBE0 DFT unc ional,
16
and de 2-TZVP
17
basis se s.
Implici C-PCM sol en model was applied o ea he sol-
a ion effec s,
18
and G imme’s empi ical co ec ion wi h
Becke–Johnson damping o model he dispe sion o ces.
19
All
calcula ed minimum s uc u es we e s a iona y poin s on he
po en ial su ace ee o imagina y equencies and all an-
si ion s a e s uc u es ha e one imagina y equency co es-
ponding o he eac ion coo dina e hey a e desc ibing. The
op imized Ca esian coo dina es o he a oms in all compu ed
species a e gi en in sec ion 5.4 in ESI.†
Resul s and discussion
Fo ma ion o [RuCl
2
(CO)
2
(ERR′)
2
] (E = S, Se, Te; R, R′= Me, Ph)
In o ganic sol en s, [RuCl
2
(CO)
3
]
2
eac s wi h o ganic mono-
chalcogenides o o m [RuCl
2
(CO)
2
(ERR′)
2
] (eqn (1)).
RuCl2ðCOÞ3

2ðsÞþ4ERR′sol
ðÞ
!2 RuCl2ðCOÞ2ðERR′Þ2

sol ðÞþ2COðgÞð1Þ
The syn heses we e ca ied ou by e luxing in CH
2
Cl
2
o
THF. Though he p oduc s and hei yields we e a he simila
in bo h sol en s, he eac ion seemed o be as e in THF han
in CH
2
Cl
2
. The e was a clea end obse ed o he yields o
he complexes, as he chalcogen elemen became hea ie . In
case o [RuCl
2
(CO)
2
(SRR′)
2
] he yields we e 10–30%,
[RuCl
2
(CO)
2
(SeRR′)
2
] showed yields o 30–40%, and
[RuCl
2
(CO)
2
(TeRR′)
2
] we e o med a good yields o ca. 80%.
Molecula s uc u es
[RuCl
2
(CO)
2
(ERR′)
2
] (E = S, Se, Te; R, R′= Me, Ph). The
c ys al s uc u es o [RuCl
2
(CO)
2
(SPh
2
)
2
](3
cc
),
7
Dal on T ansac ions Pape
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[RuCl
2
(CO)
2
(TePh
2
)
2
]·1
2C
6
H
6
(9
cc
)
8
and [RuCl
2
(CO)
2
{Te
(CH
2
SiMe
3
)
2
}
2
]
9
ha e been de e mined p e iously and ha e
shown ha in each case he complex is a cc -isome in acco d-
ance wi h he ini ial sugges ion by John
6b
(see Cha 1). In his
con ibu ion we epo he c ys al s uc u es o
[RuCl
2
(CO)
2
(SMePh)
2
](2
cc
), [RuCl
2
(CO)
2
(SeMe
2
)
2
](4
cc
), and
[RuCl
2
(CO)
2
(SePh
2
)
2
](6
cc
). Spec oscopic iden i ica ion o
[RuCl
2
(CO)
2
(SeMePh)
2
](5
cc
), and he en a i e s uc u al
cha ac e iza ion o [RuCl
2
(CO)
2
(TeMePh)
2
](8
cc
) also enabled
he iden i ica ion o he molecula species (see sec ions 3 and
4 in ESI†).
I can be seen om Fig. 1 ha all de e mined complexes
a e expec edly oc ahed al cc -isome s in line wi h he p e-
iously epo ed s uc u es.
7–9
The selec ed bond pa ame e s
o he diffe en cc -[RuCl
2
(CO)
2
(ERR′)
2
] complexes a e com-
pa ed in Table S2 in ESI.†
The Ru–S, Ru–Se, and Ru–Te bond leng hs span anges o
2.3774(12)–2.4084(11), 2.4908(7)–2.5125(7), and 2.6478(7)–
2.6637(7) Å, espec i ely. The Ru–S and Ru–Se bonds appea o
be sligh ly longe han he espec i e sums o co alen adii o
2.28 and 2.41 Å,
20
bu he Ru–Te bond leng hs a e nea o he
single bonds ( he sum o he co alen adii is 2.61 Å ( e . 20)).
In e es ingly, he wo Ru–E (E = S, Se, Te) bonds in each
complex a e ben away om he egion o wo Ru–CO bonds
[ he E–Ru–E bond angles ange 164.01(3)–174.11(4)°; see
Table S2 in ESI†].
Geome ies o all [RuCl
2
(CO)
2
(ERR′)
2
] isome s we e op i-
mized using he PBE0-D3/de 2-TZVP me hod and he op i-
mized s uc u es a e summa ized in Table S5 in ESI.†The ela-
i e ene gies o he isome s diffe signi ican ly, as shown in
Fig. 2. The s abili y o de ing is cc >ccc > cc > ≈c c.
These indings a e consis en wi h he spec oscopic in e -
ence ha he cc -isome is he main isome o he
[RuCl
2
(CO)
2
(ERR′)
2
] complexes.
6b
I is suppo ed by he ela i e
ene gies o he diffe en isome s shown in Fig. 2. The ccc-
isome s a e he nex ene gy- a ou able species in all com-
plexes, bu e en hei ela i e ene gies a e 13–27 kJ mol
−1
abo e hose o he cc -isome s. All o he isome s show signi i-
can ly highe ela i e ene gies. I is in e es ing ha e en
hough bulky ligands in mu ually cis posi ions a e expec ed o
expe ience signi ican s e ic epulsion, his does no appea o
be a se ious p oblem e en in he case o EPh
2
, as can be con-
cluded om he ela i e ene gies shown in Fig. 2 and by he
simila i y o he bond pa ame e s in ques ion (see Table S5 in
ESI†). The ela i e s eng hs o he ans-in luence o he
ligands seem o play he main ole in he s abili y end.
The ans-in luence ollows he end: CO > ERR′> Cl.
When he ca bonyl g oups a e in he mu ual ans posi ions o
each o he , he Ru–C bond is signi ican ly weake han when
hey a e mu ually in cis posi ions. The e o e, he - and c c-
isome s lie signi ican ly highe in ene gy han he o he h ee
isome s. I also seems ha he ans-in luence plays a mo e sig-
ni ican ole in he ela i e leng hs o he Ru–E bonds in
diffe en isome s han he s e ic effec s due o he o ganic
g oups (see Table S2 in ESI†).
[RuCl
2
(CO)
3
(SeRR′)] (R, R′= Me, Ph). In addi ion o cc -
[RuCl
2
(CO)
2
(SeRR′)
2
] [R, R′=Me(4
cc
); R = Me, R′=Ph(5
cc
)],
he eac ions o [RuCl
2
(CO)
3
]
2
and SeMe
2
o SeMePh affo ded
colou less c ys als o [RuCl
2
(CO)
3
(SeMe
2
)] (10) and
[RuCl
2
(CO)
3
(SeMePh)] (11), espec i ely, wi h ca. 10–20% iso-
Fig. 2 Rela i e PBE0/de 2-TZVP Gibbs ene gies (in kJ mol
−1
)o
[RuCl
2
(CO)
2
(ERR’)
2
] (E = S, Se, Te; R, R’= Me, Ph). The nume ical alues
o he ela i e ene gies a e shown in Table S6 in ESI.†
Fig. 1 Molecula s uc u es o (a) cc -[RuCl
2
(CO)
2
(SMePh)
2
](2
cc
), (b) cc -[RuCl
2
(CO)
2
(SeMe
2
)
2
](4
cc
), and (c) cc -[RuCl
2
(CO)
2
(SePh
2
)
2
](6
cc
). The an-
iso opic displacemen pa ame e s a e gi en in 50% p obabili y le el. Hyd ogen a oms a e omi ed o cla i y.
Pape Dal on T ansac ions
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la ed yields. Thei c ys al s uc u es a e shown in Fig. 3 and
he selec ed bond pa ame e s a e lis ed in Table S4 in ESI.†
The bond pa ame e s o 10 and 11 a e as expec ed. The
s onge ans-in luence o selenium compa ed o ha o chlo -
ine esul s in he bond leng h Ru1–C3 o be longe han hose
o Ru1–C1 and Ru1–C2 [1.944(5) s. 1.895(4)–1.903(5) Å and
1.946(3) s. 1.892(3)–1.901(3) Å in 10 and 11, espec i ely].
Consequen ly, C3–O3 is somewha sho e han C1–O1 and
C2–O2 in case o bo h complexes, hough he diffe ence is no
s a is ically signi ican .
The ou e o he eac ion o [RuCl
2
(CO)
3
]
2
and ERR′(E = S, Se,
Te; R, R′= Me, Ph)
Fo ma ion o cc -[RuCl
2
(CO)
2
(ERR′)
2
]. [RuCl
2
(CO)
3
]
2
and
ERR′(E = S, Se, Te; R, R′= Me, Ph) affo d cc -
[RuCl
2
(CO)
2
(ERR′)
2
] somewha as e in THF han in CH
2
Cl
2
.
The yields, howe e , seem o be independen o he sol en .
We ha e ca ied ou DFT in es iga ion o he possible eac ion
pa hways a PBE0-D3/de 2-TZVP le el o heo y o explo e he
ole o he sol en and sol en coo dina ion o [RuCl
2
(CO)
3
]
2
in
he eac ion.
The PBE0-D3/de 2-TZVP scans o he eac ion su aces a e
exempli ied by he eac ion o [RuCl
2
(CO)
3
]
2
and EMe
2
, which
a e shown in Fig. 4 o he eac ion in THF and in Fig. 5 o
he eac ion in CH
2
Cl
2
. The ene ge ics o he possible pa ial
eac ions and he ac i a ion ene gies in bo h sol en s a e
shown in Table 2.
The eac ion in THF can be conside ed o ake place ollow-
ing wo diffe en ou es, which a e indica ed in Fig. 4. The
ou e a, which consis s o eac ion in e media es I#a(#= he
o dinal numbe along he eac ion coo dina e; 1–3) and he
ansi ion s a es TS#a(#=1–4) ha a e connec ed by g een
dashed lines, ep esen s he eac ion, in which he THF mole-
cule i s coo dina es o one o he wo u henium cen es in
[RuCl
2
(CO)
3
]
2
leading o he clea age o he bond be ween his
u henium and one b idging chlo ido ligand. The second THF
molecule hen coo dina es o he neighbou ing u henium
cen e and leads o he clea age o he bond be ween he
emaining b idging chlo ido ligand and u henium. This
esul s in he o ma ion o mononuclea [RuCl
2
(CO)
3
(THF)].
The ac i a ion ba ie s in hese wo s eps (40.2 and 32.3 kJ
mol
−1
o TS1a and TS2a, espec i ely; see Table 2) a e ela-
i ely low, and his pa o he eac ion is expec ed o be apid
e en a oom empe a u e.
The hi d s ep in ol es he subs i u ion o he THF ligand
by EMe
2
. I can be seen om Fig. 4 and Table 2 ha he ac i-
a ion ba ie is signi ican ly highe han in he wo i s s eps
(81.5, 76.1, and 63.9 kJ mol
−1
o SMe
2
, SeMe
2
, and TeMe
2
,
Fig. 3 The molecula s uc u es o (a) [RuCl
2
(CO)
3
(SeMe
2
)] (10) and
(b) [RuCl
2
(CO)
3
(SeMePh)] (11). The aniso opic displacemen pa ame e s
ha e been gi en a 50% p obabili y le el.
Fig. 4 PBE0-D3/de 2-TZVP ene gy p ofiles o wo al e na i e ou es o he eac ion o [RuCl
2
(CO)
3
]
2
and EMe
2
(E = S, Se, Te) in THF. The nume ical
alues o he ene ge ics a e shown in Table 2.
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Fig. 5 PBE0-D3/de 2-TZVP ene gy p ofile o he eac ion o [RuCl
2
(CO)
3
]
2
and EMe
2
(E = S, Se, Te) in CH
2
Cl
2
.
Table 2 PBE0-D3/de 2-TZVP Gibbs ene gy changes and ac i a ion ene gies o he indi idual s eps in he eac ion o [RuCl
2
(CO)
3
]
2
and EMe
2
in THF
and CH
2
Cl
2
Reac ion
Gibbs ene gy (kJ mol
−1
)
E=S E=Se E=Te
[RuCl
2
(CO)
3
]
2
+EMe
2
in THF
a
Rou e a
Indi idual eac ion s eps
1
2[RuCl
2
(CO)
3
]
2
+1
2THF ⇄1
2[Ru(THF)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1a)ΔG(1a) 15.1 15.1 15.1
1
2[Ru(THF)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1a)+1
2THF ⇄[RuCl
2
(CO)
3
(THF)] (I2a)ΔG(2a)−3.6 −3.6 −3.6
[RuCl
2
(CO)
3
(THF)] (I2a) + EMe
2
⇄[RuCl
2
(CO)
3
(EMe
2
)] (I3a,b) + THF ΔG(3a)−40.8 −45.9 −60.6
[RuCl
2
(CO)
3
(EMe
2
)] (I3a,b) + EMe
2
⇄[RuCl
2
(CO)
2
(EMe
2
)
2
](P)+CO ΔG(4a,b) 9.8 4.2 −15.7
T ansi ion s a es
1
2[RuCl
2
(CO)
3
]
2
+1
2THF ⇄1
2TS1a E
a
(1a) 40.2 40.2 40.2
1
2[Ru(THF)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1a) + THF ⇄1
2TS2a E
a
(2a) 32.3 32.3 32.3
[RuCl
2
(CO)
3
(THF)] + EMe
2
⇄TS3a E
a
(3a) 81.5 76.1 63.9
[RuCl
2
(CO)
3
(EMe
2
)] + EMe
2
⇄TS4a,b E
a
(4a,b) 149.6 145.2 130.2
Rou e b
Indi idual eac ion s eps
1
2[RuCl
2
(CO)
3
]
2
⇄1
2[RuCl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1b)ΔG(1b) 33.7 33.7 33.7
1
2[RuCl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1b)+1
2EMe
2
⇄1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2b)ΔG(2b)−41.9 −45.7 −54.7
1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2b)+1
2EMe
2
⇄[RuCl
2
(CO)
3
(EMe
2
)] (I3a,b)ΔG(3b)−21.0 −22.3 −28.0
[RuCl
2
(CO)
3
(EMe
2
)] (I3a,b) + EMe
2
⇄[RuCl
2
(CO)
2
(EMe
2
)
2
](P)+CO ΔG(4a,b) 9.7 4.2 −15.7
T ansi ion s a es
1
2[RuCl
2
(CO)
3
]
2
⇄1
2TS1b E
a
(1b) 36.4 36.4 36.4
1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2b)+1
2EMe
2
⇄1
2TS2b E
a
(2b) 36.5 41.7 38.2
1
2[RuCl
2
(CO)
3
(EMe
2
)] + 1
2EMe
2
⇄TS4a,b E
a
(4a,b) 149.6 145.2 130.2
[RuCl
2
(CO)
3
]
2
+EMe
2
in CH
2
Cl
2b
Indi idual eac ion s eps
1
2[RuCl
2
(CO)
3
]
2
⇄1
2[RuCl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1′)ΔG(1′) 33.1 33.1 33.1
1
2[RuCl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I1′)+1
2EMe
2
⇄1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2′)ΔG(2′)−41.4 −45.2 −54.2
1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2′)+1
2EMe
2
⇄[RuCl
2
(CO)
3
(EMe
2
)] (I3′)ΔG(3′)−21.4 −22.7 −28.4
[RuCl
2
(CO)
3
(EMe
2
)] (I3′) + EMe
2
⇄[RuCl
2
(CO)
2
(EMe
2
)
2
](P)+CO ΔG(4′) 7.8 4.5 −15.3
T ansi ion s a es
1
2[RuCl
2
(CO)
3
]
2
⇄1
2TS1′E
a
(1′) 35.8 35.8 35.8
1
2[Ru(EMe
2
)Cl(CO)
3
(μ-Cl)RuCl
2
(CO)
3
](I2′)+1
2EMe
2
⇄1
2TS2′E
a
(2′) 36.6 41.2 37.6
1
2[RuCl
2
(CO)
3
(EMe
2
)] + 1
2EMe
2
⇄TS3′E
a
(3′) 149.6 144.9 130.2
a
See Fig. 4.
b
See Fig. 5.
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espec i ely). In e es ingly, he [RuCl
2
(CO)
3
(EMe
2
)] complexes
hus o med a e e y s able. The inal s ep leading o he o -
ma ion o he end-p oduc s cc -[RuCl
2
(CO)
2
(SeMe
2
)
2
](P) is he
subs i u ion o CO by EMe
2
. The ac i a ion ba ie s o his
s ep a e he highes in case o all eac ions (149.6–130.2 kJ
mol
−1
, see Table 2).
Rou e b( eac ion in e media es I#band he ansi ion
s a es TS#b) ep esen s he eac ion pa h, in which he he mal
ene gy esul s in he clea age o he b idging Ru–Cl bond
wi hou coo dina ion o he sol en THF. The in e media e I1b
shows a e y shallow local minimum. When EMe
2
is in o-
duced, he in e media e I2b is o med wi hou an ac i a ion
ba ie . I should be no ed, howe e , ha THF can also eac
wi h I1b in a simila ashion o o he chalcogenides wi hou
he ac i a ion ba ie , which would esul in he o ma ion o
[RuCl(CO)
3
(THF)(μ-Cl)RuCl
2
(CO)
3
], ha is iden ical o I1a (con-
nec ed by a ed dashed line; see Fig. 4).
A emp s o ind a ansi ion s a e o he conce ed coo di-
na ion o EMe
2
and he clea age o he b idging Ru–Cl leading
o he di ec o ma ion o [RuCl(CO)
3
(EMe
2
)(μ-Cl)RuCl
2
(CO)
3
]
(in e media e I2b) om [RuCl
2
(CO)
3
]
2
esul ed in ansi ion
s a es ha we e much highe in ene gy. This ende s he con-
ce ed eac ion mechanism unlikely.
The expe imen al suppo o he coo dina ion o he
sol en o he wo u henium a oms in [RuCl
2
(CO)
3
]
2
comes om
he obse a ion ha some eac ion ba ches affo ded colou less
c ys als, which we e shown by c ys al s uc u e de e mina ion o
be [RuCl
2
(CO)
3
(THF)] (I2a;seeFig.4).Thes uc u eo I2a has
been epo ed p e iously by G ay and Duffey.
21
The de ec ion o
his complex in some eac ion ba ches indica es ha THF indeed
coo dina es o [RuCl
2
(CO)
3
]
2
, bu he o ma ion o I1a could
equally well ollow ei he he ou e ao ou e b, o bo h.
The addi ion o he second EMe
2
o [RuCl(CO)
3
(EMe
2
)(μ-Cl)
RuCl
2
(CO)
3
](I2b) gene a es I3b, which is iden ical o I3a. The
las s ep in ol ing he subs i u ion o CO by EMe
2
yielding Pis
iden ical in bo h al e na i e ou es.
The compa ison o he ene ge ics in he ou es aand bin
Fig. 4 and Table 2 indica es ha he he mal opening o he
b idging Ru–Cl bond in [RuCl
2
(CO)
3
]
2
is compe i i e o he
ini ial coo dina ion o he sol en , and he addi ion o EMe
2
o
he ee coo dina ion si e esul s in [RuCl(CO)
3
(EMe
2
)(μ-Cl)
RuCl
2
(CO)
3
] (in e media e I2b), which lies lowe in ene gy
han [RuCl(CO)
3
(THF)(μ-Cl)RuCl
2
(CO)
3
] (in e media e I1a)o
[RuCl
2
(CO)
3
(THF)] (in e media e I2a). The e is a signi ican ly
highe ene gy ba ie om I2a o I3a,b han om I2b o I3a,b.
The las s ep in he eac ion is iden ical in bo h al e na i e
pa hways and shows he highes ene gy ba ie . I is he a e-
de e mining s ep o he o e all eac ion.
When he eac ion is ca ied ou in CH
2
Cl
2
, he coo di-
na ion o he sol en o [RuCl
2
(CO)
3
]
2
does no ake place. The
ene gy p o ile o his eac ion is shown in Fig. 5, and he
PBE0-D3/de 2-TZVP ene ge ics o he indi idual eac ion s eps
a e shown in Table 2. All in e media es (I1′–I3′) and he end-
p oduc Pagain show local minima wi h only eal equencies,
and all ansi ion s a es (TS1′–TS3′) show only one imagina y
equency each along he eac ion coo dina e.
I can be seen om Fig. 5 ha he eac ion p o ile in
CH
2
Cl
2
is i ually iden ical wi h ha shown o he eac ion in
THF wi hou sol en coo dina ion (c . ou e bin Fig. 4). The
i s in e media e I1′again lies in he shallow local ene gy
minimum and he in oduc ion o he i s me hyl chalcogen-
ide o he unsa u a ed i e-coo dina e u henium cen e in I1′
p oceeds wi hou he ac i a ion ba ie . The addi ion o he
second me hyl chalcogenide ligand p oceeds acco ding o he
in e change mechanism, wi h he ac i a ion ba ie a he low
and o he same o de o magni ude as in he eac ion in THF.
The e o e, he clea age o he b idging Ru–Cl bonds is also
expec ed o ake apidly place e en a oom empe a u e.
The ac i a ion ba ie s in he inal subs i u ion s ep (CO
subs i u ed by he second EMe
2
) a e almos iden ical ega d-
less o he sol en (see Table 2) and de e mine he o e all a e
o he eac ion. I can be in e ed ha he main ac o in he
obse ed as e eac ion a e in THF compa ed o ha in
CH
2
Cl
2
is due o he highe boiling poin o THF ( he boiling
poin o THF is 66 °C and ha o CH
2
Cl
2
is 40 °C).
The composi ion o he diffe en eac ion mix u es has
been moni o ed as a unc ion o ime by
13
C{
1
H},
77
Se, and
125
Te NMR spec oscopy, as app op ia e. This is exempli ied by
he eac ion o SeMe
2
wi h [RuCl
2
(CO)
3
]
2
in CH
2
Cl
2
(see Fig. 6).
The isola ion and s uc u al and spec oscopic cha ac e iz-
a ion o bo h [RuCl
2
(CO)
3
(SeMe
2
)] (10;
77
Se chemical shi
55 ppm) and cc -[RuCl
2
(CO)
2
(SeMe
2
)
2
](5
cc
;
77
Se chemical shi
88 ppm) p o ide expe imen al indica ion ha he eac ion
leading o he o ma ion cc -[RuCl
2
(CO)
2
(ERR′)
2
] p oceeds ia
he in e media e o ma ion o [RuCl
2
(CO)
3
(ERR′)] (see Fig. 6).
Fig. 6 The
77
Se NMR spec a o he eac ion mix u e o SeMe
2
and
[RuCl
2
(CO)
3
]
2
in CH
2
Cl
2
upon eflux.
Dal on T ansac ions Pape
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The esonance a 41 ppm, which was de ec ed in he ea ly
s ages o he eac ion, educed in in ensi y as a unc ion o
ime and is en a i ely assigned o [Ru(EMe
2
)Cl(CO)
3
(μ-Cl)
RuCl
2
(CO)
3
](I2b). While his species has no been isola ed
and unambiguously iden i ied, he PBE0-D3/de 2-TZVP ene -
ge ics indica e ha he o ma ion o I2b is a ou able. I s
77
Se
NMR chemical shi also shows a easonable alue.
Fu he mo e, he obse ed dec ease o in ensi y o esonance
a 41 ppm as he eac ion p og esses is consis en wi h he
esonance a ising om an in e media e species like I2b.
The o ma ion o [RuCl
2
(CO)
3
(ERR′)] (E = S, Se, Te; R, R′=
Me, Ph) could also be de ec ed in some o he eac ion ba ches
by NMR spec oscopy. The
13
C{
1
H} (see Fig. S6 in ESI†) and
77
Se NMR spec a o [RuCl
2
(CO)
3
(SeMePh)] (11) we e eco ded
om edissol ed c ys als isola ed om he eac ion mix u e
( he spec oscopic assignmen is discussed in sec ion 4.4 in
ESI†). The
13
C esonances o he espec i e eac ion o SMePh
and [RuCl
2
(CO)
3
]
2
we e assigned om he
13
C{
1
H} spec um
eco ded di ec ly om he eac ion solu ion (see Fig. S4 in
ESI†) by compa ison o he
13
C{
1
H} spec um eco ded o he
edissol ed c ys als o cc -[RuCl
2
(CO)
2
(SMePh)
2
](2
cc
) (see
Fig. S7 in ESI†). The eac ion mix u e o [RuCl
2
(CO)
3
]
2
and
TeMePh showed a
125
Te NMR esonance a 374 ppm, which
disappea ed in a ew days. Taking in o accoun he epo ed
app oxima e ela ionship be ween
125
Te and
77
Se chemical
shi s in ela ed alkyl ellu ides [δ(Te) = (1.8)·δ(Se)
22
], i can be
concluded ha he assignmen o his esonance o
[RuCl
2
(CO)
3
(TeMePh)] is consis en wi h he obse ed
77
Se
chemical shi o 192 pm o [RuCl
2
(CO)
3
(SeMePh)].
Possible al e na i e eac ion p oduc s. I can be seen om
Fig. 2 ha while cc -[RuCl
2
(CO)
2
(ERR′)
2
] complexes a e ene ge-
ically he mos s able isome s, he nex a ou able isome s
ccc-[RuCl
2
(CO)
2
(EMe
2
)
2
] lie 15.4, 19.0, and 26.8 kJ mol
−1
highe in ene gy o SMe
2
, SeMe
2
, and TeMe
2
, espec i ely. The
espec i e alues o EMePh a e 19.5, 20.4, and 26.3 kJ mol
−1
,
and o EPh
2
14.3, 13.7, and 21.1 kJ mol
−1
. Whe eas he o -
ma ion o hese isome s migh be possible, we ha e no seen
any indica ions ha any eac ions would ha e affo ded ccc-
[RuCl
2
(CO)
2
(ERR′)
2
]. We ca ied ou PBE0-D3/de 2-TZVP ene gy
scan o he inal eac ion s ep o he eac ion o es he
plausibili y o o ma ion o he ccc-isome s (see eqn (2)):
½RuCl2ðCOÞ3ðERR′Þ þ ERR′
!ccc ½RuCl2COðÞ
2ðERR′Þ2þCO ð2Þ
The ene gy p o iles and he compu ed ene gy alues in he
eac ion in ol ing EMe
2
a e shown in Fig. 7.
The calcula ions clea ly show ha o ma ion o ccc-
[RuCl
2
(CO)
2
(EMe
2
)
2
] is less likely han ha o cc -
[RuCl
2
(CO)
2
(EMe
2
)
2
]. I can be seen om Fig. 7 ha he ac i-
a ion ene gies o he ansi ion s a es leading o he ccc-
isome a e ca. 30 kJ mol
−1
highe han hose leading o he o -
Fig. 7 The compa ison o he ene gy p ofiles o he eac ions [RuCl
2
(CO)
3
(EMe
2
)] + EMe
2
→cc -[RuCl
2
(CO)
2
(EMe
2
)
2
] + CO (g een line) and
[RuCl
2
(CO)
3
(EMe
2
)] + EMe
2
→ccc-[RuCl
2
(CO)
2
(EMe
2
)
2
] + CO (blue line) in THF. The ΔG
alues a e fixed by gi ing each in e media e I3a,b he ela i e
alue o 0 kJ mol
−1
.
Pape Dal on T ansac ions
Dal on T ans. This jou nal is © The Royal Socie y o Chemis y 2022
Open Access A icle. Published on 12 July 2022. Downloaded on 7/27/2022 10:12:31 AM.
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C ea i e Commons A ibu ion 3.0 Unpo ed Licence.
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