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Inorganica Chimica Acta 312 (2001) 201 – 204
Note
Further investigations into the isomerism of Cu(II) complexes of
diphenylsulfimide: the preparation and X-ray crystal structure of
{[Cu(Ph
2
SNH)
4
][CuBr
2
(Ph
2
SNH)
2
]Br
2
}, the first example of a
{[CuL
4
][CuX
2
L
2
]X
2
} structure
Paul F. Kelly
a,
*, Alexandra M.Z. Slawin
b
, Kevin W. Waring
a
, Sonia Wilson
a
a
Department of Chemistry, Loughborough Uniersity, Loughborough, Leicestershire LE11 3TU, UK
b
Department of Chemistry, St.Andrews Uniersity, St Andrews, Scotland, UK
Received 7 June 2000; accepted 12 September 2000
Abstract
Green crystalline [Cu(Ph
2
SNH)
4
][CuBr
2
(Ph
2
SNH)
2
]Br
2
(2) forms when the product of the reaction of CuBr
2
with Ph
2
SNH (1)
(molar ratio 1:3) in MeCN is extracted into CH
2
Cl
2
–60/80 petroleum ether and the solvents allowed to evaporate slowly. The
product is notable for two reasons: not only does it contain the CuBr
2
(Ph
2
SNH)
2
unit in the hitherto unseen planar isomer (the
free material forming only the pseudo-tetrahedral isomer), but, more significantly, it is also the first example of a structurally
characterised [CuL
4
][CuX
2
L
2
]X
2
system. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Isomerism; Copper(II) complexes; Crystal structures; Sulfimides
As part of our continuing interest in the coordination
chemistry of sulfur – nitrogen species we have recently
reported on the reactivity of S,S -diphenylsulfimide,
Ph
2
SNH (1), towards a number of metal centres. This
work has resulted in the isolation of a range of prod-
ucts including complexes of 1 (such as [Co(Ph
2
SNH)
6
]-
Cl
2
, which, unexpectedly, exhibits strong, concerted,
directed hydrogen bonding between both sets of triple
NH units on either side of the coordination octahe-
dron) [1] and of metal-assisted nitrile adducts of 1 [2].
We have also shown that a range of copper complexes
may be formed; these include the homoleptic
[Cu(Ph
2
SNH)
4
]
2 +
cation and oxo-bridged clusters of
the type [Cu
4
(
4
-O)(-X)
6
(Ph
2
SNH)
4
] (X =Cl or Br) [3].
An intriguing aspect of the copper coordination chem-
istry of 1 was revealed by the observation that trans -
[CuCl
2
(Ph
2
SNH)
2
], the product of the 2:1 reaction of 1
with CuCl
2
, can crystallise in either square-planar or
pseudo-tetrahedral geometries [4]. Such isomerism ap-
pears to be unique for a neutral Cu(II) species and the
compound thus provided an important addition to the
known examples of concomitant polymorphs [5]. Subse-
quently, we showed that the bromo analogue trans -
[CuBr
2
(Ph
2
SNH)
2
] can only be isolated in a
pseudo-tetrahedral form [3]. All these results indicate
that the coordination chemistry of 1 is not as straight-
forward as one might have expected, a conclusion
reinforced by the observations presented in this work.
The reaction of 1 with CuBr
2
(molar ratio 3:1) in
MeCN results in a green solution. If the solvent is
removed, the residue taken into CH
2
Cl
2
and treated
with 60/80 petroleum ether, slow evaporation to half
volume yields a mass of well-formed glistening green
crystals. X-ray crystallography reveals these to corre-
spond to the formula [Cu(Ph
2
SNH)
4
][CuBr
2
-
(Ph
2
SNH)
2
]Br
2
(2), i.e. they contain both the homo-
leptic cation and the neutral trans -CuBr
2
(Ph
2
SNH)
2
in
* Corresponding author. Tel.: +44-1509-263171; fax: +44-1509-
223925.
E-mail address: p.f.kelly@lboro.ac.uk (P.F. Kelly).
0020-1693/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
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