Department of Chemistry

The [Cu-2(O2CMe)(4)(btd)(2)] complex as a bridging unit: preparation,
characterisation, X-ray structure and magnetism of the 2D coordination
polymer [Cu-6(O2CMe)(8)(OMe)(4)(btd)(2)](n)
(btd=2,1,3-benzothiadiazole)

English

{A systematic investigation of the {[}Cu-2(O2CMe)(4) (H2O)(2)]/btd
reaction system is described, where btd = 2,1,3-benzothiadiazole.
Reaction of {[}Cu-2(O2CMe)(4)(H2O)(2)] with 5-8 equiv. of btd in both
MeCN and MeOH yields {[}Cu-2(O2CMe)(4)(btd)(2)] (1) in 40-50\% yields.
Treatment of {[}Cu-2(O2CMe)(4)(H2O)(2)] With 1.4 or 0.7 equiv. of btd in
MeOH leads to the precipitation of the polymeric compound
\{{[}Cu-6(O2CMe)(8)(OMe)(4)(btd)(2)]\} (2) in 82\% yield. Reaction of 1
with two equivalents of {[}Cu-2(O2CMe)(4)(H2O)(2)] in MeOH under reflux
provides an additional route to 2. The structure of 1 consists of
centrosymmetric dinuclear {[}Cu-2(O2CMe)(4)(btd)(2)] molecules of the
paddle-wheel cage type. The two Cu-II ions are bridged by four eta
(1):eta (1):mu (2) acetates, while a monodentate btd is at the apex of
the square pyramid of each metal centre. The 2D structure of 2 consists
of chains of tetranuclear, planar Cu-4(OMe)(4)(O2CMe)(4) repeating units
running along the a axis, which are connected along the cell body
diagonal via Cu-2(O2CMe)(4)(btd)(2) paddle-wheel dinuclear units. The
btd molecules behave as bidentate bridging ligands. Within the
tetranuclear units, each Cu-II ion is connected via two acetate bridges
with one neighbouring Cu-II ion and via two methoxo bridges with the
other neighbouring Cu-II ion; intertetranuclear linking is provided by
two monoatomic acetate bridges. The results of solid state magnetic
susceptibility studies are described for complex 2 in the temperature
range 3-300 K. The results reveal antiferromagnetic exchange
interactions between the Cu-II ions. The complicated structure of 2 does
not permit an exact treatment for the determination of the various
exchange interactions. However, an approximate 3-J magnetic model was
constructed, resulting in an excellent fit. An orbital interpretation of
the J-trend derived is also attempted. (C) 2001 Elsevier Science B.V.
All rights reserved.}

2001

Konstantina Skorda
Giannis S Papaefstathiou
Anastasios Vafiadis
Alexandra Lithoxoidou
Catherine P Raptopoulou
Aris Terzis
Vassilis Psycharis
Evangelos Bakalbassis
Vassilis Tangoulis
Spyros P Perlepes

INORGANICA CHIMICA ACTA

ELSEVIER BV

326

1

53--64

Science

https://doi.org/10.1016/s0020-1693(01)00594-1

10.1016/s0020-1693(01)00594-1

https://pergamos.lib.uoa.gr/uoa/dl/object/2928389