Synthesis and Reactivity of an Early-Transition-Metal Alkynyl Cubane Mn4C4 Cluster

Article abstract of DOI:10.1002/anie.201812529

While the coordination chemistry of monometallic complexes and the surface properties of extended metal particles are well understood, the control of metal nanocluster formation has remained challenging. The isolation of discrete metal clusters provides an especially rare snapshot at the nanoscale of cluster growth. The synthesis and full characterization of the first early-transition-metal alkynyl cubane and the first μ³-alkynyl Mn₃ motif are reported.

Full text of DOI:10.1002/anie.201812529

A Journal of the Gesellschaft Deutscher Chemiker
Angewandte
International Edition Chemie
www.angewandte.org
Accepted Article
Title: The First Earlier Transition Metal Alkynyl Cubane Cluster Mn4C4
Authors: Axel Jacobi von Wangelin, Uttam Chakraborty, Serhiy
Demeshko, and Franc Meyer
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.201812529
Angew. Chem. 10.1002/ange.201812529
Link to VoR: http://dx.doi.org/10.1002/anie.201812529
http://dx.doi.org/10.1002/ange.201812529

Angewandte Chemie International Edition
10.1002/anie.201812529
COMMUNICATION
The First Earlier Transition Metal Alkynyl Cubane Cluster Mn
4
C
4
[a]
[b]
[b]
[a]
Uttam Chakraborty,* Serhiy Demeshko, Franc Meyer, and Axel Jacobi von Wangelin*
While the coordination chemistry of monometallic complexes and the
surface properties of extended metal particles are well understood,
the control of metal nanocluster formation has remained challenging.
The isolation of discrete metal clusters constitutes an especially rare
snapshot at the nanoscale of cluster growth. This work reports the
of alkynylmetal complexes and their significance as catalytic
intermediates in many organic transformations, there are only
very few reports of discrete µ -alkynylmetal nanoclusters bearing
3
late transition metals other than group 11 metals (i.e. Ru, Rh and
Ni) and ancillary ligands.[13] Documented herein is the facile and
synthesis and full characterization of the first early-transition metal
high-yielding synthesis of a well-defined heteroleptic alkynyl-Mn
cluster, comprising the first σ,µ -alkynyl-Mn and the first early-
4
3
alkynyl cubane and the first  -alkynyl-Mn
3
motif.
3
3
transition metal-alkynyl cubane motifs (Scheme 2), its full
characterization, and application to nanoparticle formation and
catalysis.
Discrete metal nanoclusters constitute unique molecular
architectures between the regimes of monometal coordination
compounds and larger particles (Scheme 1).[1]-[3] The synthesis of
metal nanoclusters has direct ramifications for the understanding
of nanoparticle growth, materials design, metal-catalyzed reaction
mechanisms, and biological processes.[1]-[3] The presence of
several metal-metal interactions within a low-molecular weight
compound often results in optical and magnetic properties that are
distinct from monometal complexes.[2],[4] However, the synthesis
of well-defined nanoclusters of low-valent transition metals is
generally limited by low control over size, shape, and coordination
properties and the operation of undesired side reactions including
rapid cluster growth, metal oxidations, and redox disproportions.
The vast majority of literature reports involve sterically shielded
clusters with stable ligands (i.e. bridging carbonyl or heteroatomic
Ln
growth
[Red]
L
n
Ligand
Ln
nanocluster
superatom/nanoparticle
coinagemetals: L = PR
3
, RC
2
, RS
oxo, imido, nitrido ligands at coordinatively saturated metal
centers).[2],[5] These have mostly been studied toward the nature
and extent of metal−metal cooperativity.[6],[7] Catalytic applications,
however, have largely been neglected.[6],[7] Our group and Ohki et
other transitionmetals: L = CO, PR
3
, oxo, imidoetc.
Scheme 1. Transition metal clusters: The scarcity of CO-free alkynyl metal
clusters other than with coinage metals.
al. have successfully exploited the implementation of 
and  -hydrido ligands for the stabilization of various novel
nanocluster architectures.[8]-[10] This enabled the synthesis of
discrete Mn , Fe , Fe , and Fe clusters that exhibited planar
geometries (Scheme 2). Alkyne ligands constitute a distinct
and versatile class of ligands for the design of metal cluster
2
-amido
3
6
4
6
7
[
9],[10]
2
4
architectures. They offer various coordination modes (σ, π , π ;
terminal and bridging), are competent stabilizers of atomically
precise nanoclusters, and provide the opportunity for facile
removal or ligand exchange under mild condition.[11],[12]b Mostly,
stable alkynyl clusters of the coinage metals (Cu, Ag, Au) were
prepared - that benefit from the soft carbophilicity of the group 11
metals - and studied toward their photophysical properties and
catalytic activities (Scheme 1).[11],[12] Despite the broad availability
[
a]
Dr. U. Chakraborty,* Prof. Dr. A. Jacobi von Wangelin*
Department of Chemistry, University of Hamburg
Martin Luther King Pl 6, 20146 Hamburg (Germany)
E-mail: uttam.chakraborty@chemie.uni-hamburg.de;
axel.jacobi@uni-hamburg.de
[
b]
Dr. S. Demeshko, Prof. Dr. F. Meyer
Institute of Inorganic Chemistry, University of Göttingen
Tammannstr. 2, 37077 Göttingen (Germany)
Supporting information for this article is given via a link at the end of
the document.
Scheme 2. The 
manganese clusters (R=SiMe
3
-X-M motif in planar hydridomanganese and 3D-alkynyl-
).
3
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201812529
COMMUNICATION
We envisioned the synthesis of alkynylmetal clusters based on a
C–Mn angles (89.4 and 90.8°). The Mn–Mn distances are in good
agreement with those of other MnII
N
[16],[17]
heterocubane clusters
(hmds) (2.85622(3)–
formal exchange of the 
3
-bridging hydrido ligands of our
4
4
previously reported planar transition metal clusters with ,
3
-
and only slightly longer than in Mn
6
H
6
6
2.97627(3) Å).[ The tetranuclear Mn cluster 2 is the first well-
defined, isolated alkynyl-bridged cubane containing low-valent,
open-shell Mn ions. This structural motif has so far been
exclusively known from alkynyl coinage metal clusters. Beside the
general interest in the special electronic and magnetic properties
of multi-metallic complexes for materials and catalysis
applications, cubic manganese clusters bear a close structural
10]
alkynyl ligands which are well documented for the soft carbophilic
coinage metals and very few other late transition metals.[11],[13]
Accordingly, the reaction of divalent Mn[N(SiMe ) ] (1) with
3 2 2
phenylacetylene in n-hexane afforded a yellow-orange solution
which upon cooling led to the novel alkynylmanganese complex
{
Mn(µ
3
-C≡CPh)(N[SiMe
3
]
2
)}
4
(2, Scheme 3). This nanocluster
cubane structure in 80%
crystallized in an unprecedented Mn
4
C
4
yield. The yellow-orange crystals turned into a khaki solid upon
drying under vacuum (mp. 118 °C, which gave an orange-yellow
liquid; decomp. at 166 °C). The UV-VIS spectrum in n-hexane
exhibited two bands at 405 nm (broad) and 479 nm (weak). The
relationship to the central Mn
4
O
4
cluster of the oxygen-evolving-
complex.[
18]
Other known examples of such Mn X cluster
4 4
topologies involve group 15 and 16 ligands.[17]-[19] A similar M
heterocubane structure with two different groups of FeIII atoms
was recently observed in a [Fe (SAr)
] cluster.[20]
X
4
4
-1
characteristic C≡C IR absorption of the solid at 2012 cm is in full
4
S
4
4
1
1
agreement with that of dicopper µ
2
-η :η - and tricopper µ
η :η :η -alkynyl complexes. The H NMR signals of the para-
magnetic complex 2 were very broad and weak (−100 to 100 ppm). The solution magnetic moment of 2 (5.7  in C D ;  T = 4.1
3
-
1
1
1
[14]
1
We further investigated the structure and reactivity of the cubane.
B
6
6
M
3
–1
cm mol K) is indicative of strong antiferromagnetic interactions
between the Mn(II) ions (spin-only value of four uncoupled Mn(II)
3
–1
ions: 11.8

B
;
17.5 cm mol K). Temperature-dependent
magnetic measurements on solid 2 were in full agreement:
3
–1
Starting at 6.1 cm mol K at r.t., 
M
T decreased to almost zero at
1
5 K indicating a diamagnetic S = 0 ground state (Figure 2). The
T
experimental magnetic data were simulated based on the
Heisenberg–Dirac-van-Vleck (HDvV) spin Hamiltonian for two
isotropic exchange coupling constants (Figure 2, inset) and
[21]
Zeeman splitting (PHI program, see ESI for more details): The
–
1
coupling J
cubane faces with shorter Mn–Mn distances (3.08 Å) and J
1
1
(–24.5 cm ) represents the interaction via the two
(–
0.4 cm ) via the four faces with longer Mn–Mn distances (3.23
2
–
1
Å). So far, µ
Even for the simplest dinuclear µ
3
-alkynyl-Mn complexes have not been reported.
-alkynyl complexes[
15],[22]
only
2
–
1
one structure was magnetically characterized (J = –30.5 cm ,
d(Mn–Mn) = 2.97 Å).[15] The observed coupling constants in 2
correlate well with the Mn–Mn distances and are much higher
than for dinuclear Mn(II) complexes containing heteroatomic
bridging ligands (phenoxides, halides, azides: ǀJǀ ≤ 5 cm ) due
to the more covalent Mn–C bond character.
4 4
Scheme 3. Synthesis and reactivity of the Mn C -cubane cluster 2.
The molecular structure of 2 was confirmed by single crystal X–
ray crystallography (Figure 1). The central Mn core is an
almost perfect cube containing alternating Mn and C atoms in
-1 [23]
4
C
4
slightly distorted T
tetrahedron is capped with one µ
d
symmetry. Each Mn
3
1
triangle of the Mn
4
1
1
3
-η :η :η -bridging -alkynyl
ligand; each Mn center coordinates one terminal hexamethyl-
disilazide (hmds) ligand. In comparison, the µ -H-bridged Mn
arranged in a nearly planar nanosheet
3
3
units in [MnH(hmds)]
6
geometry.[
10]
The Mn–C distances (2.21771(4), 2.27113(4),
2
.31275(7) Å ) and C≡C bond lengths (1.22291(2) Å ) in 2 are
1
1
comparable with those of the bimetallic
2
µ -η :η -alkynyl
complexes [(nacnac)Mn(C≡CPh)] and [CpMn(C≡CPh)(THF)]
2
2
15]
(
nacnac = HC{CMeN(2,6-iPr
2
C
6
H
3
)}
, Cp = cyclopentadienyl).[
2
1
1
1
The
3
µ -η :η :η -bridging alkynylmetal motif is very well
[
11]
documented for the coinage metals Cu, Ag, and Au. Examples
containing other transition metals are very rare, with only a
handful of µ
Rh and Ni reported.[13] Related Mn complexes have hitherto been
unknown. The distorted Mn tetrahedron of 2 contains two
3
-alkynyl complexes of the late transition metals Ru,
4
different environments around Mn comprising two shorter Mn–Mn
distances (3.07999(4) Å ) with smaller Mn–C–Mn angles of 86.6°
and four longer Mn–Mn distances (3.22525(6) Å) with wider Mn–
Figure 1. Solid state structure of 2 (50% probability level; H atoms omitted).
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201812529
COMMUNICATION
1
[29]
characteristic broad H resonances at 5.5–8 ppm. The initially
formed white suspension and slow color change to dark-brown
may indicate the intermediacy of alkynyl-manganese oligomers
2
under catalytic conditions. The reaction of Mn(hmds) with 2 equiv.
phenylacetylene (or 2 with 1 equiv. phenylacetylene) presumably
gave rise to the formation of heterogeneous Mn(0) species upon
deprotonation, coordination, and reductive elimination of 1,4-di-
phenylbutadiyne. Under related conditions, we have recently
reported the first efficient Mn-catalyzed hydrogenation of alkenes,
alkynes, and imines under mild conditions.[10] Various Mn
catalysts have recently been reported for the hydrogenation of
carbonyl derivatives,[
30],[31]
whereas olefin hydrogenations are
very rare.[10] Some of the reported Mn catalysts even tolerate the
presence of alkenes under hydrogenation conditions.[31] We
therefore evaluated combinations of 1/phenylacetylene as
catalysts in hydrogenations. Various alkenes and alkynes
underwent clean hydrogenation to the fully saturated products at
M
Figure 2. Temperature-dependent magnetization  T for 2. Solid red line is the
best fit with J = –24.5 cm , J = –10.4 cm , g = fixed at 2.0. Inset: Magnetic
1 2
–1
–1
coupling scheme used for the simulation.
2
5 bar H and 70°C (Scheme 4B). The cubane 2 (1.25 mol%) also
catalyzed the hydrogenation of alkenes but with significantly lower
activity for diphenylacetylene than the in situ catalyst mixture (5
mol% 1 + 10 mol% phenylacetylene). Mono- and di- substituted
alkenes were hydrogenated with very high yields (Scheme 4).
However, the compatibility with other polar functional groups is
limited (Scheme 4 and Table S1). Rapid hydrodebromination was
observed with 4-bromo--methylstyrene.
The modular structure of 2 offers ample opportunities for catalytic
applications[24] and further cluster manipulation by ligand
exchange toward functionalized cubanes and supramolecular
Mn-cages.[
20],[25]
We investigated conditions for small molecule
coordination or bond activation and the exchange of the residual
amido ligands with other n-, - and -ligands. In the presence of
alcohols or water, 2 underwent rapid decomposition, most likely
by ligand protonation. No reactivities were observed for reactions
between
2 and cyclohexyl bromide and diphenyldiazene,
respectively. With 1 equiv. benzyl azide, the formation of an
unidentified paramagnetic species was observed. Addition of the
bifunctional S,O-ligand and CH-acid 2-acetylthiophene
(
equimolar to 2) resulted in complete consumption of the
substrate and elimination of HN(SiMe . Attempts to obtain
3 2
)
suitable single crystals of the resultant paramagnetic light yellow
product were unsuccessful. The IR spectrum of the solid exhibited
a C=O absorption at 1594 cm-1 that is 56 cm lower in energy than
-1
-1
free 2-acetylthiophene. The C≡C-IR stretch (2048 cm ) appeared
as a weak band at slightly lower energy than for cluster 2 (2012
-1 [26]
cm ). The presence of an alkynyl transition metal moiety in 2
prompted us to study the catalytic activity of 2 in alkyne reactions.
A recent report from our group has successfully demonstrated the
cyclotrimerization of terminal alkynes with catalytic Fe(hmds)
2
.[27]
A similarly effective reaction with Mn catalysts has not been
reported.[10],[28] An equimolar solution of 2 with phenylacetylene in
n-hexane afforded an off-white insoluble precipitate (Scheme 3).
Complete consumption of phenylacetylene and elimination of
1
HN(SiMe
3
)
2
was verified by H NMR (see SI). We postulate the
formation of oligomeric bis(alkynyl)manganese complexes
Mn(C≡CPh) that decomposed at 151 °C. A suspension of the
[
2 n
]
insoluble oligomer in THF underwent color change at 60 °C to give
a dark brown mixture. The concomitant formation of 1,4-diphenyl-
1
,3-butadiyne suggests the operation of a reductive elimination
pathway that would lead to the formation of Mn(0) particles
Scheme 3). Paralleling our report of iron-catalyzed cyclo-
trimerization, Mn(hmds) and 2 proved to be moderately active in
the catalytic cyclotrimerization of phenylacetylene, respectively
Scheme 4A). The remaining substrate presumably underwent
polymerization, which resulted in an orange solid with the
Scheme 4. Catalytic activity of the 1/phenylacetylene-derived Mn nanoparticles:
A) (Cyclo)oligomerization of phenylacetylene. B) Hydrogenation of
(
2
alkenes/alkynes. Standard conditions: 0.2 mmol alkene/alkyne,
5
mol%
Mn[N(SiMe
3
)
2
]
2
, 10 mol% phenylacetylene, toluene (2 mL), 5 bar H
2
, 20 h, 70 °C.
a
Yields determined by quantitative GC-FID vs. n-pentadecane. reaction with
(
1.25 mol% 2.
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201812529
COMMUNICATION
In summary, we have demonstrated that the formal substitution of
Häkkinen, N. Zheng, J. Am. Chem. Soc. 2015, 137, 4324; c) P. Maity, S.
Takano, S. Yamazoe, T. Wakabayashi, T. Tsukuda, J. Am. Chem. Soc.

3
-hydrido with 
3
-alkynyl ligands effects a change from a 2D to a
nanocluster constitutes
2013, 135, 9450; d) Y. Wang, X.-K. Wan, L. Ren, H. Su, G. Li, S. Malola,
3D Mn cluster topology. The resultant Mn
4
S. Lin, Z. Tang, H. Häkkinen, B. K. Teo, Q.-M. Wang, N. Zheng, J. Am.
Chem. Soc. 2016, 138, 3278.
the first earlier transition metal cubane cluster comprising an
Mn core and a heteroleptic ligand periphery of alkynyl and
4
C
4
[
13]
S. A. MacLaughlin, N. J. Taylor, A. J. Carty, Organometallics 1984, 3,
amido groups; the former motif was hitherto known only from
coinage metal clusters. The crystal structure documents the
presence of two sets of Mn(II) environments; SQUID magnetic
studies exhibited strong antiferromagnetic interactions via two
different Mn-Mn coupling patterns. The reactivity profile of the
3
92; b) D. Nucciarone, N. J. Taylor, A. J. Carty, Organometallics 1986,
5, 2565; c) P. Blenkiron, G. D. Enright, P. J. Low, J. F. Corrigan, N. J.
Taylor, Y. Chi, J.-Y. Saillard, A. J. Carty, Organometallics 1998, 17,
2447; d) S. Tanaka, C. Dubs, A. Inagaki, M. Akita, Organometallics 2004,
23, 317; e) S. Tanaka, C. Dubs, A. Inagaki, M. Akita, Organometallics
2005, 24, 163; f) T. Yamaguchi, T. Koike, M. Akita, Organometallics
2010, 29, 6493; g) M. Maekawa, M. Munakata, T. Kuroda-Sowa, K.
novel Mn
and acid-base, alkyne cyclotrimerization, and hydrogenation
reactions. The simple combination of Mn(hmds) and phenyl-
4
cluster was explored in Mn(0) nanoparticle formation
Hachiya, Inorg. Chim. Acta 1995, 233, 1.
2
[
[
14]
15]
a) M. S. Ziegler, K. V. Lakshmi, T. D. Tilley, J. Am. Chem. Soc. 2017,
acetylene provides a rare example of a Mn alkene hydrogenation
catalyst and leaves ample opportunities for further development.
139, 5378; b) J. Diez, M. P. Gamasa, J. Gimeno, A. Aguirre, S. Garcia-
Granda, Organometallics 1991, 10, 380.
a) J. Chai, H. Zhu, H. W. Roesky, Z. Yang, V. Jancik, R. Herbst-Irmer,
H.-G. Schmidt, M. Noltemeyer, Organometallics 2004, 23, 5003; b) C. S.
Alvarez, S. R. Boss, J. C. Burley, S. M. Humphry, R. A. Layfield, R. A.
Kowenicki, M. McPartlin, J. M. Rawson, A. E. H. Wheatley, P. T. Wood,
D. S. Wright, Dalton Trans. 2004, 3481.
Acknowledgements
This work was generously financed by the European Research
Council (ERC CoG 683150). S.D and F.M acknowledge support
from the University of Göttingen.
[
16]
U. Riese, B. Neumüller, N. Faza, W. Massa, K. Dehnicke, Z. Anorg. Allg.
Chem. 1997, 623, 351.
[17]
H.-J. Mai, R. M. zu Köcker, S. Wocadlo, W. Massa, K. Dehnicke, Angew.
Chem. Int. Ed. 1995, 34, 1235.
[
[
18]
19]
S. Mukhopadhyay, S. K. Mandal, S. Bhaduri, W. H. Armstrong, Chem.
Rev. 2004, 104, 3981.
Keywords: cluster • manganese • alkyne • cubane •
hydrogenation • cyclotrimerization
a) U. Riese, N. Faza, W. Massa, K. Harms, T. Breyhan, P. Knochel, J.
Ensling, V. Ksenofontov, P. Gütlich, K. Dehnicke, Z. Anorg. Allg. Chem.
1999, 625, 1494; b) M. Reyes-Lezama, H. Höpfl, N. Zúñiga-Villarreal,
Organometallics 2010, 29, 1537; c) H.-O. Stephan, G. Henkel, Angew.
Chem. Int. Ed. 1994, 33, 2322; d) S. B. Copp, S. Subramanian, M. J.
Zaworotko, J. Am. Chem. Soc. 1992, 114, 8719; e) S. Heinl, K. Kiefer,
G. Balázs, C. Wickleder, M. Scheer, Chem. Commun. 2015, 51, 13474.
G. Moula, T. Matsumoto, M. E. Miehlich, K. Meyer, K. Tatsumi, Angew.
Chem. Int. Ed. 2018, 57, 11594.
References
[
1]
I. Chakraborty, T. Pradeep, Chem. Rev. 2017, 117, 8208.
[
2]
P. Braunstein, L. A. Oro, P. R. Raithby, Metal Clusters in Chemistry,
Wiley-VCH, Weinheim, 1999.
[
[
3]
4]
L. Guczi, A. Beck, A. Horváth, D. Horváth, Top. Catal. 2002, 19, 157.
a) G. Karotsis, S. J. Teat, W. Wernsdorfer, S. Piligkos, S. J. Dalgarno, E.
K. Brechin, Angew. Chem. Int. Ed. 2009, 48, 8285; b) D. Gatteschi, R.
Sessoli, J. Villain, Molecular Nanomagnets, Oxford University Press,
Oxford, 2006; c) R. Sessoli, D. Gatteschi, A. Caneschi, M. A. Novak,
Nature 1993, 365, 141; d) U. Kreibig, M. Vollmer, Optical Properties of
Metal Clusters, Springer, Berlin, 1995; e) V. W.-W. Yam, V. K.-M. Au, S.
Y.-L. Leung, Chem. Rev. 2015, 115, 7589.
[20]
[21]
[22]
[23]
N. F. Chilton, R. P. Anderson, L. D. Turner, A. Soncini, K. S. Murray, J.
Comp. Chem. 2013, 34, 1164.
S. Kheradmandan, T. Fox, H. W. Schmalle, K. Venkatesan, H. Berke,
Eur. J. Inorg. Chem. 2004, 2004, 3544.
a) Y. Gao, Y. Ji, S. Ding, Z. Liu, J. Tang, Z. Anorg. Allg. Chem. 2011,
637, 2300; b) J. Chaignon, S.-E. Stiriba, F. Lloret, C. Yuste, G. Pilet, L.
Bonneviot, B. Albela, I. Castro, Dalton Trans. 2014, 43, 9704.
J. R. Carney, B. R. Dillon, S. P. Thomas, Eur. J. Org. Chem. 2016, 3912.
a) Y. Ohki, Y. Sunada, M. Honda, M. Katada, K. Tatsumi, J. Am. Chem.
Soc. 2003, 125, 4052; b) Y. Ohki, Y. Sunada, K. Tatsumi, Chem. Lett.
2005, 34, 172.
[
[
5]
6]
a) D. M. P. Mingos, R. H. Crabtree, Comprehensive Organometallic
Chemistry III, Elsevier, Amsterdam, 2007, 1st ed. Vol 5 and 6; b) C. E.
Holloway, M. Melnik, J. Organomet. Chem. 1990, 396, 129.
[24]
[25]
a) A. R. Fout, D. J. Xiao, Q. Zhao, T. D. Harris, E. R. King, E. V. Eames,
S.-L. Zheng, T. A. Betley, Inorg. Chem. 2012, 51, 10290; b) A. R. Fout,
Q. Zhao, D. J. Xiao, T. A. Betley, J. Am. Chem. Soc. 2011, 133, 16750;
c) E. Y. Tsui, M. W. Day, T. Agapie, Angew. Chem. Int. Ed. 2011, 50,
[26]
2 5
For cyclometallation of 2-acetylthiophene with PhCH Mn(CO) see: a) M.
1
668; d) Q. Zhao, T. A. Betley, Angew. Chem. Int. Ed. 2011, 50, 709; e)
J. Camacho-Bunquin, M. J. Ferguson, J. M. Stryker, J. Am. Chem. Soc.
013, 135, 5537; f) R. H. Sánchez, A. M. Willis, S.-L. Zheng, T. A. Betley,
I. Bruce, Angew. Chem. Int. Ed. 1977, 16, 73; b) J. M. Cooney, L. H.P.
Gommans, L. Main, B. K. Nicholson, J. Organomet. Chem. 1988, 349,
197.
2
Angew. Chem. Int. Ed. 2015, 54, 12009.
[27]
[28]
[29]
[30]
[31]
D. Brenna, M. Villa, T. N. Gieshoff, F. Fischer, M. Hapke, A. Jacobi von
Wangelin, Angew. Chem. Int. Ed. 2017, 56, 8451.
[
[
7]
8]
a) E. L. Muetterties, M. J. Krause, Angew. Chem. Int. Ed. 1983, 22, 135;
b) P. J. Dyson, Coord. Chem. Rev. 2004, 248, 2443.
Y. Kuninobu, M. Nishi, A. Kawata, H. Takata, Y. Hanatani, S. S. Yudha,
A. Iwai, K. Takai, J. Org. Chem. 2010, 75, 334 and references therein.
A. R. Grimm, D. F. Sauer, T. Polen, L. Zhu, T. Hayashi, J. Okuda, U.
Schwaneberg, ACS Catal. 2018, 2611.
a) Y. Ohki, Y. Shimizu, R. Araake, M. Tada, W. M. C. Sameera, J.-I. Ito,
H. Nishiyama, Angew. Chem. Int. Ed. 2016, 55, 15821; b) R. Araake, K.
Sakadani, M. Tada, Y. Sakai, Y. Ohki, J. Am. Chem. Soc. 2017, 139,
5596.
F. Kallmeier, R. Kempe, Angew. Chem. Int. Ed. 2018, 57, 46 and refs.
therein.
[
9]
T. N. Gieshoff, U. Chakraborty, M. Villa, A. Jacobi von Wangelin, Angew.
Chem. Int. Ed. 2017, 56, 3585.
a) F. Kallmeier, T. Irrgang, T. Dietel, R. Kempe, Angew. Chem. Int. Ed.
2016, 55, 11806; b) S. Elangovan, C. Topf, S. Fischer, H. Jiao, A.
Spannenberg, W. Baumann, R. Ludwig, K. Junge, M. Beller, J. Am.
Chem. Soc. 2016, 138, 8809.
[
10]
U. Chakraborty, E. Reyes-Rodriguez, S. Demeshko, F. Meyer, A. Jacobi
von Wangelin, Angew. Chem. Int. Ed. 2018, 57, 4970.
[
[
11]
12]
A. K. Gupta, A. Orthaber, Chem. Eur. J. 2018, 7536.
a) X.-K. Wan, J.-Q. Wang, Z.-A. Nan, Q.-M. Wang, Sci. Adv. 2017, 3,
e1701823; b) Y. Wang, H. Su, C. Xu, G. Li, L. Gell, S. Lin, Z. Tang, H.
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201812529
COMMUNICATION
Entry for the Table of Contents (Please choose one layout)
COMMUNICATION
The first non-coinage metal M
4
C
4
U. Chakraborty,* S. Demeshko, F.
cubane has been prepared and
characterized. The nanocluster
contains two sets of Mn(II)
Meyer, A. Jacobi von Wangelin*
Page No. – Page No.
environments that exhibit strong
The first earlier transition metal
alkynyl cubane cluster Mn C
4 4
antiferromagnetic coupling. Facile
amido ligand exchange and formation
of Mn nanoparticles have been
evaluated in catalytic studies.
This article is protected by copyright. All rights reserved.