Chemistry Reference
In-Depth Information
Figure 4.29
Linear chain of compound [Cd
2
(N6-benzyladenine)
2
(
µ
-Cl)
4
Cl
2
]
n
Figure 4.30
Polymeric chain of compound {[HgCl
2
(1,9-dimethyl-guanine-
N7
)]·2HgCl
2
}
n
Stanley and coworkers have reported the structures of two monodimensional
polymers of N6-substituted adenine derivatives (N6-furfuryladenine and N6-
benzyladenine) coordinated to Cd(II)
33
. Both ligands present interesting properties
as plant growth stimulants.
34
In these structures, the Cd(II) ions adopt a distorted
octahedral geometry, with coordination to N9 and fi ve chloride ions. Successive
Cd(II) ions are bridged by two chloride ions (Figure 4.29).
Lippert and coworkers have synthesized a 1D polymeric Hg(II)-nucleobase
complex from the guanine derivative (1,9 - DiMeG = 1,9 - dimethylguanine), by the
reaction of HgCl
2
in a water/alcohol mixture (Figure 4.30). The Hg(II) ion is coor-
dinated to one guanine (via the N7 position) and three Cl ligands, two of which act
as bridging ligands. The polymeric structure is cocrystallized with HgCl
2
molecules.
35
Two isomorphous Cd polymers of chelate-tethered adenine derivatives have
been characterized. Reactions of Cd(II) salts with A-Et-enH·Cl in water yielded
material with the stoichiometry [{Cd
2
X
6
(A - Et - en)
2
}
n
] (X = Cl and Br). Each com-
pound contains two unique Cd(II) ions: a central cadmium which sits on a centre
of symmetry and is coordinated in an octahedral manner by four bridging halide
anions and the N7 of two
trans
-arranged adenines. The second cadmium adopts a
distorted octahedral geometry with three halide ligands, two of these bridging and
