The ambiguous behaviour of diphosphines towards the quasilinear iron(i) complex [Fe(N(SiMe3)2)2]--between inertness, P-C bond cleavage and C-C double bond isomerisation

Article abstract of DOI:10.1039/c9cc08968c

Chelating phosphines are widely used as robust and reliable ligands in catalysis. We show that the anionic iron(i) complex [Fe^I(N(SiMe₃)₂)₂]^- is able to selectively cleave a P-aryl bond of 1,2-bis(diphenylphosphino)benzene. Furthermore, the related cis-1,2-bis(diphenylphosphino)-ethylene (dppee) binds not to the P donors but to the ethylene unit, and is (catalytically) transformed to the trans-isomer.

Full text of DOI:10.1039/c9cc08968c

View Article Online
View Journal
ChemComm
Chemical Communications
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: G. Werncke and I.
Müller, Chem. Commun., 2020, DOI: 10.1039/C9CC08968C.
Volume 54
This is an Accepted Manuscript, which has been through the
Number
January 2018
Pages 1-112
1
4
Royal Society of Chemistry peer review process and has been
accepted for publication.
ChemComm
Chemical Communications
rsc.li/chemcomm
Accepted Manuscripts are published online shortly after acceptance,
before technical editing, formatting and proof reading. Using this free
service, authors can make their results available to the community, in
citable form, before we publish the edited article. We will replace this
Accepted Manuscript with the edited and formatted Advance Article as
soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes to the
text and/or graphics, which may alter content. The journal’s standard
Terms & Conditions and the Ethical guidelines still apply. In no event
shall the Royal Society of Chemistry be held responsible for any errors
or omissions in this Accepted Manuscript or any consequences arising
from the use of any information it contains.
ISSN 1359-7345
COMMUNICATION
S. J. Connon, M. O. Senge et al.
Conformational control of nonplanar free base porphyrins:
towards bifunctional catalysts of tunable basicity
rsc.li/chemcomm

Please do not adjust margins
Page 1 of 5
ChemComm
View Article Online
DOI: 10.1039/C9CC08968C
COMMUNICATION
The Ambiguous Behaviour of Diphosphines Towards the
Quasilinear Iron(I) Complex [Fe(N(SiMe3)2)2]- – Between Inertness,
P−C Bond Cleavage and C−C Double Bond Isomerisation
Received 00th January 20xx,
Accepted 00th January 20xx
Christian Gunnar Werncke,*a and Igor Müllera
DOI: 10.1039/x0xx00000x
Chelating phosphines are widely used as robust and reliable ligands interested if the observed inertness of compound 1 towards
in catalysis. We show, that the anionic iron(I) complex pure Lewis bases holds true for a variety of commonly used
[FeI(N(SiMe3)2)2]- is able to selectively cleave a P-aryl bond of 1,2- (chelating) Lewis base additives used in catalysis, especially
bis(diphenylphosphino)benzene. Further, the related cis-1,2- diphosphines. This would shed light onto the behaviour of these
bis(diphenylphosphino)-ethylene (dppee) binds not by the P donors additives towards low-coordinate, low-valent 3d-metal species
but by the ethylene unit, and is (catalytically) transformed to the observed or postulated in a variety of catalytic transformations,
trans-isomer.
especially those where anionic metallates are likely such as in
Grignard based C−C cross-coupling.13
Tertiary phosphines are common ligands in organometallic
chemistry that are mainly used to stabilize metal centres in
medium to low oxidation states. They are usually seen as robust
spectator ligands that can be easily modified concerning its
electronic and steric properties. As such they are widely used as
co-ligands in many catalytic transformations.1 However, the
cleavage and/or scrambling of the P−aryl and to a lesser extent
P−alkyl bonds in ligating phosphines is sometimes observed and
can pose an unwanted deactivation pathway in catalysis.2,3 This
is mainly the case for 2nd and 3rd row transition metals
(especially Pd).4 For 3d-metals less is known about P−C bond
cleavage, and is mainly observed for metal carbonyls upon
prolonged heating.3,5 Rare exceptions for reported conversions
under mild conditions involve (di)cobalt,6,7 diiron8 and
When compound 1 is subjected to regular O- or N-Donors such
as simple ethers (THF, dimethoxy ethane), N-methyl-2-
pyrrolidone (NMP), amines (NEt3, TMEDA) or pyridine
derivatives (4-dimethylaminopyridine, 4-tert-butylpyridine) no
reaction is observed. This holds also true for carbenes (IDipp,
SIMes, SIDipp), PEt3 and larger monodentate phosphines as well
as
chelating
phosphines
like
Xanthphos,
1,2-
bis(diethylphosphino)ethane or 1,2-bis(diphenylphosphino)
methane/ethane as well as propane. This implicates, that low-
coordinate, low-valent anionic iron complexes might display
only weak interactions with mono- and bidentate phosphines,
which is emphasized by the lack of respective complexes.14
Employing 1,2-bis(diphenylphosphino) benzene (dppbz), a
further commonly used ligand framework, it reacted with
complex 1 under formation of a dark red solution within 30
minutes. Workup afforded a mixture of colourless as well as
blood red crystals. The former turned out to be
K{18c6}[FeII(N(SiMe3)2)3], 2, (18c6 = 18-crown-6) whereas the
latter is the tetrahedral phenyliron(II) complex 3 (Scheme 1),
whose equimolar formation was shown by 1H NMR
spectroscopy. The phenyl group is result of the P−C bond
cleavage of one P−Ph units of the dppbz ligand which now acts
as an anionic phosphine/phosphanide ligand (ppbz* = 1-
(diphenylphosphino)-2-(phenylphosphido)benzene)). The Fe1–
P1 and Fe1–P2 bond lengths amount 2.4557(6) Å and 2.4096(5)
which reflects the difference between the phosphine and
phosphide unit. Together with the tetrahedral geometry of the
phosphide moiety, whereas the free lone pair points away from
the iron ion, it indicates the absence of significant double bond
character of the iron-phosphide bond.
dinickel7,9
carbonyl
compounds
and
the
bis(diphenylphosphino)methane ligand resulting in bridged
phosphide complexes. P−C bond cleavage for carbonyl free 3d-
metal systems was only seen in case of a nickel complex.10
Recently we reported on the synthesis of the quasi-linear iron(I)
complex K{18-crown-6}[Fe(N(SiMe3)2)2], 1.11 Despite a sterically
unhindered metal centre, preliminary examinations showed
that it is unaffected by monodentate lewis bases like PPh3, PCy3,
P(OEt)3 or the N-hetero cyclic carbene IMes. This behaviour is
peculiar for two-coordinate metal(I) ions,12 and might be result
of the anionic state of the complex anion in 1. We were thus
a. Dr. C. Gunnar Werncke, Igor Müller, Fachbereich Chemie, Philipps-University
Marburg, Hans-Meerwein-Straße, D-35043 Marburg, Germany, e-mail:
gunnar.werncke@chemie.uni-marburg.de
Electronic Supplementary Information (ESI) available: Experimental details and
crystallographic details, NMR and UV/Vis spectra. See DOI: 10.1039/x0xx00000x
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 5
COMMUNICATION
Journal Name
bis(diphenylphosphino) ethylene (dppee). ReactiVoienw AorfticldepOpnleinee
DOI: 10.1039/C9CC08968C
-
-
with complex 1 in THF gave a rapid colour change to brown.
Ph
Ph
Ph
Ph
hmds
P
Ph2P
After stirring over night the reaction mixture was filtered and
then layered with pentane to give reddish violet crystals after
storage at −40°C for a few days (Scheme 2). X-Ray diffraction
analysis revealed the presence of the dppee iron complex 4
(Figure 2). The iron centre, besides two hmds ligands, exhibits a
diphosphine ligand, which astonishingly binds not via the
phosphine atoms but solely by the C−C double bond of the
backbone. This behaviour is unprecedented for any
mononuclear transition metal complex with dppee or a related
diphosphine ligand. Such an ethylene coordination was only
observed for binuclear complexes where the ethylene bridged
diphosphine already coordinated to a second metal ion via the
P donor atoms or when it is enforced by the backbone of the
diphosphine.18 Further, in complex 4 the phosphine atoms are
situated in a trans-arrangement, revealing a cis–>trans double
bond isomerisation. The C1−C2 bond length amounts to
1.438(2) Å which is between the values of free dppee (1.334(4)
Å)19 and 1,2-bis(diphenylphosphino) ethane (1.521(7) Å).20 The
planes span by N1−Fe1−N2 and C1−Fe1−C2 are twisted by
approximately 26° towards each other.
Ph
P
2 FeI
Fe0
= dppbz
hmds
THF, 30 min
P
hmds
1
Ph
A
+ FeII
2
-
[
(hmds)3] ( )
-
Ph
Ph
Ph
P
3
FeII
hmds
P
Ph
Scheme 1. Reaction of 1 with 1,2-bis(diphenylphosphino)benzene (dppbz) and proposed
iron(0) intermediate responsible for the P–aryl bond cleavage. K+{18c6} was omitted.
Figure 1. Section of the crystal structure of complex 3. The K{18c6} cation was omitted.
Selected bond lengths (Å) and angles (°): Fe1–P1 2.4557(6), Fe1–P2 2.4096(5), Fe1–N1
1.9886(13), Fe1–C1 2.068(2), P1–Fe1–P2 77.32(2), P1–Fe1–C1 101.15(5), P1–Fe1–N1
114.47(4), P2–Fe1–C1 117.93(5), P2–Fe1–N1 115.16(4), C1–Fe1–N1 120.75(6).
-
-
H
hmds
FeI
P
Ph2
hmds
hmds
P
P
Ph2
Ph2
Fe
4
(trans)
THF, 1d
1
Complex 3 exhibits a number of paramagnetic H NMR signals
hmds
H
P
Ph2
owing to the asymmetric nature of the formed ppbz* ligand.
The magnetic susceptibility of compound 3 of eff = 5.29 B is
expected for a high spin iron(II) complex. This example of an
iron mediated P–aryl bond cleavage at mild conditions is rare
(vide supra). Moreover, the use of the asymmetric ppbz* as a
ligand is unknown so far and its parent protonated form was
only detected as a side product in the unselective reaction of
dppbz with alkali metals.15 The inertness of 1 towards other aryl
phosphines, and the stability of the related complexes
[FeI(dppbz)2(X)] (X = Br, Cl, p-tolyl)16 implicated that the
presence of an iron(I) ion is not necessarily sufficient in P–aryl
bond rupture. Thus, we hypothesized that the formation of 3 is
result of a disproportionation of 1 into the observed iron(II)
complex 2 as well as the proposed iron(0) species A via formal
e-/hmds exchange (Scheme 1) which is triggered by dppbz, due
to the additional presence of the unsaturated ligand backbone.
A would then facilitate the formal intramolecular oxidative
addition of a P−Aryl unit to the iron centre. This behaviour is
similar the one of the nickel(0) complex [Ni0(IMe4)2(PPh3)]
which rapidly transforms into [NiII(IMe4)2(Ph)(PPh2)]
(IMe4=l,3,4,5- tetramethylimidazol-2-ylidene) and contrasts the
behaviour of phosphine stabilized iron(0) species which prefer
cyclometallation via adjacent C−H bonds of the phosphine
substituents, especially in case of aryl groups.17
Ph2P PPh2
THF, 1 min
-
-
P
Ph2
P
H
Ph2
H
hmds
hmds
hmds
hmds
Fe
5
Fe
H
H
Ph2
P
Ph2
P
(cis)
Scheme 2. Synthesis of complexes 4 and 5 and proposed isomerisation mechanism.
Figure 2. Sections of the crystal structure of complexes 4 and 5. K{18c6} cations,
disorders and hydrogen atoms are omitted (with the exception of the ethylene H atoms).
Selected bond lengths (Å) and angles (°): (4) Fe1–C1 2.085(2), Fe1–C2 2.064(2), Fe1–N1
2.009(2), Fe1–N2 2.000(2); C1–C2 1.438(3), N1–Fe1–N2 116.33(7). (5) Fe1–C1 2.153(12),
Fe1–C2 2.1187(12), Fe1–N1 2.001(6), Fe1–N2 1.998(6), C1–C2 1.463(15); N1–Fe1–N2
116.4(2).
Given the observed reactivity of dppbz with 1, which contrasts
the inertness of arylated diphosphines with a saturated
backbone such as dppe, we speculated about some degree of
back donation or partial electron transfer from the metal to the
ligand backbone that might initiate redox disproportionation
and formation of 3. As such we turned our attention to cis-1,2-
The 1H NMR spectrum of isolated 4, which can also directly be
obtained when reacting 1 with trans-dppee, shows one set of
paramagnetically shifted signals, with the signal attributed for
the hmds protons at −4.53 ppm which is similar to the value
observed for iron(II) bound hmds ligands.21 The magnetic
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 5
ChemComm
Please do not adjust margins
Journal Name
COMMUNICATION
susceptibility of compound 4 amounts to eff = 4.38 B and not the phosphorous atoms is observed. Further, an unusual
View Article Online
DOI: 10.1039/C9CC08968C
corresponds to the values of other low-coordinate iron(I) alkene cis–>trans isomerisation of this very bond took place, that
complexes.22 However, given the strong elongation of the C=C involved no apparent metal hydride or allyl species, and could
double bond it implicates significant charge transfer from iron be performed on a catalytic scale. Overall, it shows that for low-
to the alkyne.
coordinate, anionic iron complexes (and potentially of other
1
An immediately recorded H-NMR spectrum of the reaction of metals) the role of phosphines as a simple and robust P donor
compound 1 with cis-dppee gave a single set of paramagnetic ligand should not be readily assumed.
signals attentively attributed to the cis-isomer 5 (hmds = −2.67
ppm), which transformed completely to compound 4 over the
course of three days (45% after 16 h). The identity of the cis-
Conflicts of interest
dppee complex 5 was confirmed by X-ray diffraction analysis. In
complex 5 The C1−C2 bond length of the iron bound dppee
amounts to 1.463(15) Å which is even more elongated than in
case of the trans-complex 4. The planes spanned by N1−Fe1−N2
and C1−Fe1−C2 are also more twisted (56.6(7)°), which is
probably due to the different steric demand of cis-dppee.
The observed metal mediated cis–>trans C−C double bond
isomerisation is rather unexpected. It is commonly seen during
olefin metathesis, mediated by a metal hydride via 1,2-addition
to a C−C double bond or scrambling of a metal (hydride) bound
allylic species.23 However, in our case such possibilities can be
excluded due to the absence of a metal hydride species or allylic
substrate positions. The only comparable example is an iron
mediated stilbene isomerisation, although the mechanism and
the identity of the iron species remained elusive.24 As in
complex 5 the C=C bond of cis-dppee is significantly elongated
this very bond could be sufficiently weakened to allow for the
rotation of the substituents. A more speculative mechanism
would be a reversible formal 1e--transfer from the metal(I) ion
to the substrate (similar to complex 1 mediated irreversible
reduction of 2,2’-bipyridine)25 under intermittent formation of
a formally metal(II) ion bound 1-cis-alkenyl radical anion.
Alkenyl radical anions are calculated to exhibit no rotational
barrier, however were so far not observed in the proximity of a
metal ion.26 As the C=C isomerisation is an electroneutral
process, we aspired a catalytic transformation. Indeed, when
employing 10% of compound 1 cis-dppee is slowly isomerized
over the course of several days, (66%, r.t. 6 d, Scheme 3).
However, the catalysis is limited by simultaneous
decomposition of complex 1 within this timeframe.
There are no conflicts to declare.
Notes and references
1
a) R. Martin and S. L. Buchwald, Acc. Chem. Res., 2008, 41,
1461–1473; b) T. J. Colacot, Chem. Rev., 2003, 103, 3101–3118;
c) L. M. Pignolet, Homogeneous Catalysis with Metal Phosphine
Complexes, Springer, New York, NY, 2013; d) C. A. Tolman,
Chem. Rev., 1977, 77, 313–348; e) R. H. Crabtree, J.
Organomet. Chem., 2005, 690, 5451–5457; f) L. C. Misal Castro,
H. Li, J.-B. Sortais and C. Darcel, Green Chem., 2015, 17, 2283–
2303;
2
a) A. W. Parkins, Coord. Chem. Rev., 2006, 250, 449–467;
b) P. W.N.M. van Leeuwen, Applied Catalysis A: General,
2001, 212, 61–81; c) E. Igartúa-Nieves, A. J. Rivera-Brown
and J. E. Cortés-Figueroa, Inorg. Chem. Commun., 2012,
21, 43–46;
3
4
P. E. Garrou, Chem. Rev., 1985, 85, 171–185.
a) D. K. Morita, J. K. Stille and J. R. Norton, J. Am. Chem.
Soc., 1995, 117, 8576–8581; b) T. Rünzi, U. Tritschler, P.
Roesle, I. Göttker-Schnetmann, H. M. Möller, L. Caporaso,
A. Poater, L. Cavallo and S. Mecking, Organometallics,
2012, 31, 8388–8406; c) W. H. Watson, G. Wu and M. G.
Richmond, Organometallics, 2006, 25, 930–945; d) F. E.
Goodson, T. I. Wallow and B. M. Novak, J. Am. Chem. Soc.,
1997, 119, 12441–12453; e) W. H. Watson, S. Kandala and
M. G. Richmond, J. Organomet. Chem., 2007, 692, 1648–
1652;
5
a) A. G. Abatjoglou and D. R. Bryant, Organometallics,
1984, 3, 932–934; b) N. M. Doherty, G. Hogarth, S. A.R.
Knox, K. A. Macpherson, F. Melchior, D. A.V. Morton and
A.G. Orpen, Inorganica Chim. Acta, 1992, 198-200, 257–
270; c) R. A. Dubois and P. E. Garrou, Organometallics,
1986, 5, 466–473; d) N. M. Doherty, G. Hogarth, S. A. R.
Knox, K. A. Macpherson, F. Melchior and A. G. Orpen,
Chem. Commun., 1986, 540–542; e) R. A. Dubois, P. E.
Garrou, K. D. Lavin and H. R. Allcock, Organometallics,
1984, 3, 649–650;
Scheme 3. Catalytic cis->trans isomerisation of cis-dppee mediated by complex 1.
Concluding, we presented the peculiar behaviour of the two-
coordinate iron(I) complex 1 towards commonly used
phosphine and diphosphine ligands. Thereby it shows, that
most phosphines (as well as various N/O donor ligands) do not
interact with the anionic iron(I) complex 1, despite its accessible
metal ion. However, in case of dppbz the facile rupture of a
P−Aryl bond is observed leading to the formation of an iron(II)
phenyl complex ligated by
phosphine/phosphide ligand. For cis-dppee the unprecedented
sole coordination via the C=C bond of the ethylene linker but
a novel bidentate mixed
6
a) H. Xu, P. G. Williard and W. H. Bernskoetter,
Organometallics, 2013, 32, 798–806; b) S. Ahmed, D. G.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 5
COMMUNICATION
Journal Name
Holah, A. N. Hughes and R. T. Markewich, Polyhedron,
1993, 12, 1101–1102;
17 a) S. D. Ittel, C. A. Tolman, P. J. Krusic, A. D. English and J.
View Article Online
DOI: 10.1039/C9CC08968C
P. Jesson, Inorg. Chem., 1978, 17, 3432–3438; b) H. Azizian
and R. H. Morris, Inorg. Chem., 1983, 22, 6–9; c) G. Hata,
H. Kondo and A. Miyake, J. Am. Chem. Soc., 1968, 90,
2278–2281; d) F. Mohr, S. H. Privér, S. K. Bhargava and M.
A. Bennett, Coord. Chem. Rev., 2006, 250, 1851–1888;
7
8
D. J. Elliot, D. G. Holah, A. N. Hughes, H. A. Mirza and E.
Zawada, Chem. Commun., 1990, 85, 32–33.
a) G. Hogarth, J. Organomet. Chem., 1991, 407, 91–95; b)
G. Hogarth, S. A. R. Knox and M. L. Turner, Chem.
Commun., 1990, 85, 145–146;
18 a) G. B. Robertson, P. A. Tucker and P. O. Whimp, Inorg.
Chem., 1980, 19, 2307–2315; b) B. J. Barrett and V. M. Iluc,
Inorg. Chem., 2014, 53, 7248–7259; c) P. Binger, B.
Biedenbach, R. Mynott, R. Benn, A. Rufińska, P. Betz and C.
Krüger, J. Chem. Soc., Dalton Trans., 1990, 98, 1771–1777;
d) Z. Qiu, L. Deng and Z. Xie, J. Organomet. Chem., 2013,
747, 225–228;
9
M. Itazaki, N. Tsuchida, Y. Shigesato, K. Takano and H.
Nakazawa, Dalton Trans., 2016, 45, 19216–19220.
10 a) S. Sabater, M. J. Page, M. F. Mahon and M. K.
Whittlesey, Organometallics, 2017, 36, 1776–1783; b) J.
Cao, X. Huang and L. Wu, Chem. Commun., 2013, 49,
7747–7749; c) D. R. Fahey and J. E. Mahan, J. Am. Chem.
Soc., 1976, 98, 4499–4503;
19 S. J. Berners-Price, L. A. Colquhoun, P. C. Healy, K. A. Byriel
and J. V. Hanna, J. Chem. Soc., Dalton Trans., 1992, 3357.
20 C. Pelizzi and G. Pelizzi, Acta. Cryst. B, 1979, 35, 1785–
11 C. G. Werncke, P. C. Bunting, C. Duhayon, J. R. Long, S.
Bontemps and S. Sabo-Etienne, Angew. Chem. Int. Ed.,
2015, 54, 245–248.
1790.
21 C. G. Werncke, J. Pfeiffer, I. Müller, L. Vendier, S. Sabo-
Etienne and S. Bontemps, Dalton Trans., 2019, 48, 1757–
1765.
12 a) S. Pfirrmann, C. Limberg, C. Herwig, R. Stösser and B.
Ziemer, Angew. Chem. Int. Ed., 2009, 48, 3357–3361; b) T.
R. Dugan, X. Sun, E. V. Rybak-Akimova, O. Olatunji-Ojo, T.
R. Cundari and P. L. Holland, J. Am. Chem. Soc., 2011, 133,
12418–12421; c) K. C. MacLeod, R. A. Lewis, D. E.
DeRosha, B. Q. Mercado and P. L. Holland, Angew. Chem.
Int. Ed., 2017, 56, 1069–1072; d) M. I. Lipschutz, T.
Chantarojsiri, Y. Dong and T. D. Tilley, J. Am. Chem. Soc.,
2015, 137, 6366–6372; e) Y. Gao, G. Li and L. Deng, J. Am.
Chem. Soc., 2018, 140, 2239–2250; f) J. Hicks and C. Jones,
Organometallics, 2015, 34, 2118–2121; g) R. Wolf, M.
Brynda, C. Ni, G. J. Long and P. P. Power, J. Am. Chem.
Soc., 2007, 129, 6076–6077;
22 Y. Yu, J. M. Smith, C. J. Flaschenriem and P. L. Holland,
Inorg. Chem., 2006, 45, 5742–5751.
23 a) E. Larionov, H. Li and C. Mazet, Chem. Commun., 2014,
50, 9816–9826; b) M. Hassam, A. Taher, G. E. Arnott, I. R.
Green and W. A. L. van Otterlo, Chem. Rev., 2015, 115,
5462–5569; c) G. Li, J. L. Kuo, A. Han, J. M. Abuyuan, L. C.
Young, J. R. Norton and J. H. Palmer, J. Am. Chem. Soc.,
2016, 138, 7698–7704; d) E. H. P. Tan, G. C. Lloyd-Jones, J.
N. Harvey, A. J. J. Lennox and B. M. Mills, Angew. Chem.
Int. Ed., 2011, 50, 9602–9606; e) A. Kapat, T. Sperger, S.
Guven and F. Schoenebeck, Science, 2019, 363, 391–396;
f) A. Schmidt, A. R. Nödling and G. Hilt, Angew. Chem. Int.
Ed., 2015, 54, 801–804; g) G. Hilt, ChemCatChem, 2014, 6,
2484–2485; h) S. H. Hong, D. P. Sanders, C. W. Lee and R.
H. Grubbs, J. Am. Chem. Soc., 2005, 127, 17160–17161; i)
K. J. Ivin and J. C. Mol, Olefin Metathesis and Metathesis
Polymerization, Elsevier professional, s.l., 2nd edn., 1997;
13 a) R. Shang, L. Ilies, S. Asako and E. Nakamura, J. Am.
Chem. Soc., 2014, 136, 14349–14352; b) K. Gao and N.
Yoshikai, Acc. Chem. Res., 2014, 47, 1208–1219; c) J. A.
Garduño, A. Arévalo and J. J. García, Dalton Trans., 2015,
44, 13419–13438; d) R. B. Bedford, P. B. Brenner, E.
Carter, P. M. Cogswell, M. F. Haddow, J. N. Harvey, D. M.
Murphy, J. Nunn and C. H. Woodall, Angew. Chem. Int. Ed.,
2014, 53, 1804–1808;
24 M. Mayer, A. Welther and A. Jacobi von Wangelin,
ChemCatChem, 2011, 3, 1567–1571.
14 G. T. Sazama and T. A. Betley, Inorg. Chem., 2014, 53, 269–
281.
25 I. Müller, C. Schneider, C. Pietzonka, F. Kraus and C. G.
Werncke, Inorganics, 2019, 7, 117.
15 J. A. van Doom, J. H. G. Frijns and N. Meijboom, Recl. Trav.
Chim. Pays-Bas, 1991, 110, 441–449.
26 a) H. C. Wang, G. Levin and M. Szwarc, J. Am. Chem. Soc.,
1977, 99, 2642–2647; b) J. E. Gano, E. J. Jacob, P. Sekher,
G. Subramaniam, L. A. Eriksson and D. Lenoir, J. Org.
Chem., 1996, 61, 6739–6743;
16 C. J. Adams, R. B. Bedford, E. Carter, N. J. Gower, M. F.
Haddow, J. N. Harvey, M. Huwe, M. Á. Cartes, S. M.
Mansell, C. Mendoza, D. M. Murphy, E. C. Neeve and J.
Nunn, J. Am. Chem. Soc., 2012, 134, 10333–10336.
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 5
ChemComm
View Article Online
DOI: 10.1039/C9CC08968C
P
P
Ph2
Ph2
P-aryl bond
cleavage
-
hmds
FeI
P
P
Ph2
Ph2
-
cis trans
isomerisation
hmds
other
(di)phosphines
no interaction
A quasilinear iron(I) complex facilitates C-C bond isomerisation or P-aryl bond cleavage of
diphosphines but is otherwise inert to simple phosphine coordination.