DOI: 10.1002/chem.201502775
Communication
&
Coordination Chemistry
Highly Dynamic Coordination Behavior of Pn Ligand Complexes
towards “Naked” Cu+ Cations
Martin Fleischmann,[a] Stefan Welsch,[a] Eugenia V. Peresypkina,[b, c] Alexander V. Virovets,[b, c]
and Manfred Scheer*[a]
Dedicated to Professor Kenton H. Whitmire on the occasion of his 60th birthday
spheres or capsules with a fullerene-like construction of five-
and six-membered rings.[4] Reactions of Pn ligand complexes
with salts of metal cations M+ (M=Cu, Ag, Au) containing
small anions, such as halides, [BF4]À, or [PF6]À, tend to result in
almost insoluble products, which complicates further charac-
terization of the products. In the meantime, the use of the
weakly coordinating anion (WCA) [Al{OC(CF3)3}4]À ([TEF]) al-
lowed the isolation of coordination compounds including Pn
ligand complexes and the monocations Ag+,[5] Ga+,[6] In+[7]
and Tl+,[8] which have good solubility even in CH2Cl2 and show
a highly dynamic behavior in solution. Recently, a synthesis for
the Cu+ salt [Cu(o-DFB)2][TEF] (o-DFB=ortho-difluorobenzene)
was published by Krossing and co-workers.[9] Intrigued by the
fact that this “naked” Cu+ cation enabled the coordination of
Abstract: Reactions of Cu+ containing the weakly coordi-
nating anion [Al{OC(CF3)3}4]À with the polyphosphorus
complexes [{CpMo(CO)2}2(m,h2:h2-P2)] (A), [CpM(CO)2(h3-P3)]
(M=Cr(B1), Mo (B2)), and [Cp*Fe(h5-P5)] (C) are presented.
The X-ray structures of the products revealed mononu-
clear (4) and dinuclear (1, 2, 3) CuI complexes, as well as
the one-dimensional coordination polymer (5a) contain-
ing an unprecedented [Cu2(C)3]2+ paddle-wheel building
block. All products are readily soluble in CH2Cl2 and exhib-
it fast dynamic coordination behavior in solution indicated
by variable temperature 31P{1H} NMR spectroscopy.
Supramolecular
coordination
chemistry of multidentate linker
molecules connecting metal cen-
ters has become an established
field of research during the last
decades.[1] Next to a large variety
of extended metal organic
frameworks (MOFs), prominent
examples also include molecular
cycles, spheres, and cubes.[2] Our
Scheme 1. Representation of the Pn ligand complexes (n=2, 3, and 5) reacted with [Cu(o-DFB)2][TEF].
group contributed to this field in particular by the use of Pn
ligand complexes as linkers. These organometallic linker com-
plexes possess substituent-free P atoms, which can donate to
multiple metal atoms in a variety of bonding modes.[3] This
flexible coordination ability afforded a large number of unique
coordination compounds in the last years. The most prominent
examples represent “inorganic fullerenes” consisting of
[Cp*Fe(h5-P5)] (Scheme 1 C) and CuI halides, which represent
the weakly nucleophilic ligands, elemental sulfur (S8)[9] and
white phosphorus (P4),[10] we strived to investigate the reactivi-
ty of this new Cu+ source towards Pn ligand complexes under
these weakly coordinating conditions. We expect that the
higher Lewis acidity of Cu+ will have an impact on the ob-
served arrangements and facilitate different coordination
modes of the Pn complexes compared to former studies includ-
ing Ag+ and Tl+. The latter showed mainly formation of coor-
dination polymers with cyclo-P3 or cyclo-P5 ligand com-
plexes.[5–7]
[a] M. Fleischmann, Dr. S. Welsch, Prof. Dr. M. Scheer
Institut für Anorganische Chemie
Herein, we describe the reactions of [Cu(o-DFB)2][TEF] with
selected Pn ligand complexes containing two, three, and five P
atoms (Scheme 1)[11] and the full characterization of the result-
ing products. Among other new structural motifs, an unprece-
dented paddle-wheel building block was found in addition to
molecular units that have previously been proposed as inter-
mediates for aggregation in Ag+ chemistry.
Universität Regensburg, 93040 Regensburg (Germany)
[b] Dr. E. V. Peresypkina, Dr. A. V. Virovets
Nikolaev Institute of Inorganic Chemistry, Siberian Division of RAS
Acad. Lavrentyev str. 3, 630090 Novosibirsk (Russia)
[c] Dr. E. V. Peresypkina, Dr. A. V. Virovets
Novosibirsk State University
It is noteworthy that the isolated yields from all described
reactions are generally between good and excellent (ca. 50–
85%).[12] When the Cu+ source [Cu(o-DFB)2][TEF] was reacted
Pirogova str. 2, 630090 Novosibirsk (Russia)
Supporting information for this article is available on the WWW under
Chem. Eur. J. 2015, 21, 14332 – 14336
14332
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