ARTIKEL
Synthesis, Structure, and Clathration Ability of the Microporous
Three-Dimensional Coordination Polymer
3
1
[{CuCN(4,4'-bpy)} ´ 2(4,4'-bpy)]
O. Teichert and W. S. Sheldrick*
Bochum, Lehrstuhl fuÈr Analytische Chemie der Ruhr-UniversitaÈt Bochum
Received December 22nd, 1999.
Professor Ulrich MuÈ ller zum 60. Geburtstag gewidmet
Abstract. The respectively yellow and red coordination poly-
mers
2
1
[(CuCN)
2
(l-4,4'-bpy)] (1) and
3
1
[{CuCN(l-4,4'-
bpy)} ´ 2(4,4'-bpy)] (2) (4,4'-bpy = 4,4'-bipyridine) may be
prepared by self-assembly of CuCN and 4,4'-bpy at the ap-
propriate molar ratio in acetonitrile solution at 100 °C. In 1
infinite CuCN chains are linked by 4,4'-bpy ligands into
lamellar polymers which exhibit short Cu ´ ´ ´ C(N) contacts
of 2.41(1) A
Ê
between one of the crystallographically inde-
pendent copper atoms and cyanide carbon atoms of a neigh-
bouring corrugated sheet. At a molar ratio of CuCN : 4,4'-
bpy below 2 : 3, the heteroaromatic ligands also adopt a
structure-directing role to afford 3, in which
2
1
[(CuCN)
2
(l-
4,4'-bpy)] sheets are now joined by additional bridging 4,4'-
bpy spacer molecules to provide a three-dimensional frame-
work, whose nanometer-sized channels (12.76 ´ 13.12 A
Ê
)
accomodate two noncoordinated 4,4'-bpy guest molecules. A
DTA/TGA trace demonstrates that these can be removed in
two steps at 150 and 176 °C.
Keywords: Copper(I) cyanide; 4,4'-Bipyridine; Coordination
polymers; Microporous framework; Clathration
Synthese, Struktur und Wirtseigenschaften des mikroporo
È
sen dreidimensionalen
Koordinationspolymers
3
1
[{CuCN(4,4'-bpy)} ´ 2(4,4'-bpy)]
Inhaltsu
È
bersicht. Die gelben bzw. roten Koordinationspoly-
mere
2
1
[(CuCN)
2
(l-4,4'-bpy)] (1) und
3
1
[{CuCN(l-4,4'-bpy)} ´
2(4,4'-bpy)] (2) (4,4'-bpy = 4,4'-Bipyridin) koÈ nnen durch
Selbstorganisation aus CuCN und 4,4'-bpy im entsprechen-
den MolverhaÈltnis in AcetonitrilloÈ sung bei 100 °C dargestellt
werden. Unendliche CuCN-Ketten werden in 1 durch 4,4'-
bpy Liganden zu lamellaren Polymeren verknuÈ pft, die kurze
Cu ´ ´ ´ C(N) Kontakte von 2.41(1) A
Ê
zwischen einem der
kristallographisch unabhaÈngigen Kupferatome und Cyanid-
Kohlenstoffatomen einer benachbarten welligen Schicht auf-
weisen. Bei MolverhaÈltnissen CuCN : 4,4'-bpy niedriger als
2:3 uÈbernehmen die heteroaromatischen Liganden auch
eine strukturdirigierende Rolle bei der Herstellung von 3,
wo Schichten
2
1
[(CuCN)
2
(l-4,4'-bpy)] nunmehr durch
zusaÈtzlich verbruÈckende 4,4'-bpy-MolekuÈlen zu einem drei-
dimensionalen Raumnetz zusammengefuÈ gt werden. Die
nanometer-dimensionierten KanaÈle (12.76 ´ 13.12 A
Ê
) in die-
sem Polymer beherbergen zwei nichtkoordinierte 4,4'-bpy
GastmolekuÈ le. Eine DTA/TGA-Analyse zeigt, dass diese
GaÈste in zwei Schritten bei 150 bzw. 176 °C entfernt werden.
Introduction
Much recent effort in the expanding field of inorganic
crystal engineering has been directed towards the ra-
tional design of microporous coordination polymers.
Most approaches to this goal have involved the em-
ployment of rigid bidentate heteroaromatic N-donor
ligands such as pyrazine (pyz) or 4,4' -bipyridine (4,4'-
bpy) to connect Group 9±12 metal ions so as to afford
cationic networks, whose connectivities and cavity
shapes may also depend on the structure-directing
properties of the necessary counter ions [1, 2]. How-
ever, although many examples of one- and two-dimen-
sional coordination polymers with organoamine
spacer molecules are now known [3], surprisingly few
reports have appeared of microporous frameworks
that can clathrate larger guest molecules with a degree
of shape or size specificity [4±12]. This failure can, in
part, be ascribed to the characteristic phenomenon of
Z. Anorg. Allg. Chem. 2000, 626, 1509±1513 Ó WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000 0044±2313/00/6261509±1513 $ 17.50+.50/0 1509
* Prof. Dr. W. S. Sheldrick,
Lehrstuhl fuÈr Analytische Chemie,
Ruhr-UniversitaÈt Bochum,
D-44780 Bochum,
Fax: (Int. Code) +(0)2 34/32-1 44 20
E-mail: shel@anachem.ruhr-uni-bochum.de