Characterization of a Novel Cu
II
/4,4’-Bipyridine Coordination Polymer
Containing Square Grids
Patricia A. M. Williams, Evelina G. Ferrer, and Enrique J. Baran*
La Plata/Argentina, CEQUINOR (CONICET/UNLP), Facultad de Ciencias Exactas, Universidad Nacional de la Plata
Oscar E. Piro
La Plata/Argentina, Departamento de Fi
´
sica and Instituto IFLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata
Eduardo E. Castellano
Sa
˜
o Carlos (SP)/Brazil, Instituto de Fisica de Sa
˜
o Carlos, Universidade de Sa
˜
o Paulo
Received May 7
th
, 2002.
Abstract. In an attempt to obtain new square grid polymers we
could prepare the copper(II) complex [Cu(4,4’-bipy)
2
(H
2
O)
2
]-
(sac)
2
· DMF (4,4’-bipy ⫽ 4,4’-bipyridine; sac ⫽ anion of sac-
charin; DMF ⫽ dimethylformamide). Its structure was determined
by single crystal X-ray diffraction methods. It crystallizes in the
orthorhombic space group Pcnb (a ⫽ 14.4994(2), b ⫽ 15.8128(3),
c ⫽ 16.6850(2) A
˚
,Z⫽ 4) and is a square grid polymer with the
Charakterisierung eines neuartigen, viereckige Gitter enthaltenden Cu
II
/4,4’-Bipyridin
Koordinationspolymer
Inhaltsübersicht. Bei Versuchen neue viereckige Gitter-Polymere zu
erhalten, gelang es den Kupfer(II)-Komplex [Cu(4,4’-bipy)
2
(H
2
O)
2
]-
(sac)
2
· DMF (4,4’-bipy ⫽ 4,4’-Bipyridin; sac ⫽ Anion des Saccha-
rins; DMF ⫽ Dimethylformamid) darzustellen. Seine Struktur
wurde röntgenographisch an Einkristallen bestimmt. Er kristalli-
siert in der orthorhombischen Raumgruppe Pcnb ( a ⫽ 14.4994(2),
1 Introduction
Crystal engineering offers potential applications for the
synthesis and development of new crystalline materials, in
particular for those with functional properties as micropo-
rous solids for molecular absorption, ion exchange and het-
erogeneous catalysis [1⫺12].For example, metal-organic
networks can be designed through coordination chemistry
methodologies and the obtained materials may mimic the
properties of zeolites and clays. In this context, several co-
ordination polymers containing 4,4’-bipyridine (4,4’-bipy)
and other bridging ligands with transition metal cations,
that form molecular binding blocks, have been synthesised
[2⫺12]. The 4,4’-bipy has been selected because of its rod
*Prof.Dr.E.J.Baran
CEQUINOR, Facultad de Ciencias Exactas, UNLP
C.Correo 962, 1900-La Plata/Argentina
FAX: (54) 221-425 9485
E-mail: baran@quimica.unlp.edu.ar
2044 WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002 0044⫺2313/02/628/2044⫺2048 $ 20.00⫹.50/0 Z. Anorg. Allg. Chem. 2002, 628, 2044⫺2048
saccharinate anions sandwiched between the complex layers and
the DMF molecules filling the square holes. UV-vis, diffuse reflec-
tance and IR spectra, room temperature magnetic susceptibility
and the thermal behaviour were also investigated.
Keywords: Copper; 4,4’-Bipyridine; Crystal structure; Spectroscopic
properties; Thermal behaviour
b ⫽ 15.8128(3), c ⫽ 16.6850(2) A
˚
,Z⫽ 4) und bildet ein viereckiges
Polymer-Gitter mit den Saccharinat-Anionen zwischen den Kom-
plex-Schichten und mit den DMF-Molekülen in viereckigen Lüc-
ken. UV-vis-, Reflexions- und IR-Spektren, sowie die magnetische
Suszeptibilität (bei Raumtemperatur) und das thermische Verhal-
ten, wurden auch untersucht.
like rigidity and length. Some of these networks are square
grid polymers which have guest molecules included in their
pores. Other ligands such as 1,4-bis(4-pyridyl)benzene and
1,4-bis(4-pyridyl)anthracene [13] have been used in order to
obtain different square grid dimensions.
As a part of our current studies on mixed metal sacchar-
inate (saccharin ⫽ o-sulphobenzimide ⫽ C
7
H
5
NO
3
S) com-
plexes [14⫺18] we have now attempted to prepare this type
of polymeric complexes, containing this anion. In this paper
we present the preparation and characterisation of the coor-
dination square grid polymer [Cu(4,4’-bipy)
2
(H
2
O)
2.
](sac)
2
· DMF.
2 Results and Discussion
2.1 Structural analysis
Crystal parameters and details of the used refinement pro-
cedures are given in Table 1, whereas Fig. 1 shows an
ORTEP [19] drawing of the molecule including the used