Structure description
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Hybrid organic-inorganic materials occupy a prominent position by virtue of
their applications in catalysis, optical materials, membranes, and sorption
(Ngo et al., 2004; Evans et al., 2001; Vioux et al.,
2004; Sanchez et al., 2003; Evans & Lin, 2001; Jannasch, 2003; Javaid
et al., 2001; Honma et al., 2001; Sudik et al., 2005;
Rowsell et al., 2004; Kitaura et al., 2002). The design of
organic-inorganic hybrid materials is conceived of the metal, metal cluster,
or metal oxide substructure as a node from which rigid or flexible multitopic
organic ligands radiate to act as tethers to adjacent nodes in the bottom-up
construction of complex extended architectures. While a variety of organic
molecules have been investigated as potential tethers, materials incorporating
multitopic carboxylates and pyridine ligands have witnessed the most
significant development. However, ligands offering alternative tether lengths,
different charge-balance requirements, and orientations of donor groups may
afford advantages in the design of materials. One such ligand is 1,2,4-
triazole, a member of the polyazaheteroaromatic family of compounds, which
exhibit an extensively documented ability to bridge metal ions to afford
polynuclear compounds. Triazole is an attractive ligand for the design of
novel hybrid materials because of the unusual structural diversity associated
with the di- and trinucleating properties of the neutral and anionic ligand
forms, respectively. Herein, one new complex,[(1,2,4-triazolato) iron(II)
chloride]n, obtained from 1,2,4-triazole and iron dichloride under
hydrothermal reaction is reported, which is iso-structural to reported ones
(Gao et al., 2007a,b; Ouellette et al., 2006; Kröber
et al., 1995).
The coordination polyhedron of the iron atom is shown in Fig. 1 and can be
described as a slightly distorted tetrahedron. The iron cation is surrounded
by three crystallographically independent nitrogen atoms belonging to three
different triazolato ligands, and a chlorine atom. The Fe—N bond lengths are
in the range of 1.998–2.022 Å, very close to each other. The Fe—Cl bond
length is 2.238 Å. The bond angles around the iron atom are in the range of
106.47 to 113.23 Å. The polymeric layers as shown in Fig. 2 is formed due to
the triply bridging nature of the 1,2,4-triazolato moieties. The
1,2,4-triazolato ligand is simultaneously bound to three different iron atoms
through its three nitrogen atoms, and its symmetry is very close to C2v. A
layer contains both binuclear units and tetranuclear cavities. In the
binuclear unit two iron atoms are bridged by two nearly coplanar triazolato
groups through the 1,2-positions, affording a six-membered ring around an
inversion center; the Fe···Fe separation within the binuclear unit is equal to
3.781 Å. The chlorine atoms bonded to the metals of a binuclear unit point
out in opposite parallel directions. Each binuclear unit is further connected
to four parallel units through the four positions of the triazolato groups.
Four adjacent units, which are pairwise parallel, afford sixteen-membered
tetranuclear cavities. In such a cavity the two nearest neighbor iron atoms
are bridged by a single triazolate group through the 1,4 positions with
Fe···Fe separations of 5.785 and 6.202 Å.
For background information, see: Evans et al. (2001); Evans & Lin (2001);
Honma et al. (2001); Jannasch (2003); Javaid et al. (2001);
Sudik et al. (2005); Kitaura et al. (2002); Rowsell et
al. (2004); Sanchez et al. (2003); Suzuki et al. (2002);
Vioux et al. (2004). For the isostructural compounds, see: MnII (Gao
et al., 2007a); CoII (Ouellette et al., 2006); NiII
(Gao et al., 2007b); ZnII (Kröber et al., 1995). For
related literature, see: Ngo et al. (2004).
Hybrid organic-inorganic materials occupy a prominent position by virtue of their applications in catalysis, optical materials, membranes, and sorption (Ngo et al., 2004; Evans et al., 2001; Vioux et al., 2004; Sanchez et al., 2003; Evans & Lin, 2001; Jannasch, 2003; Javaid et al., 2001; Honma et al., 2001; Sudik et al., 2005; Rowsell et al., 2004; Kitaura et al., 2002). The design of organic-inorganic hybrid materials is conceived of the metal, metal cluster, or metal oxide substructure as a node from which rigid or flexible multitopic organic ligands radiate to act as tethers to adjacent nodes in the bottom-up construction of complex extended architectures. While a variety of organic molecules have been investigated as potential tethers, materials incorporating multitopic carboxylates and pyridine ligands have witnessed the most significant development. However, ligands offering alternative tether lengths, different charge-balance requirements, and orientations of donor groups may afford advantages in the design of materials. One such ligand is 1,2,4- triazole, a member of the polyazaheteroaromatic family of compounds, which exhibit an extensively documented ability to bridge metal ions to afford polynuclear compounds. Triazole is an attractive ligand for the design of novel hybrid materials because of the unusual structural diversity associated with the di- and trinucleating properties of the neutral and anionic ligand forms, respectively. Herein, one new complex,[(1,2,4-triazolato) iron(II) chloride]n, obtained from 1,2,4-triazole and iron dichloride under hydrothermal reaction is reported, which is iso-structural to reported ones (Gao et al., 2007a,b; Ouellette et al., 2006; Kröber et al., 1995).
The coordination polyhedron of the iron atom is shown in Fig. 1 and can be described as a slightly distorted tetrahedron. The iron cation is surrounded by three crystallographically independent nitrogen atoms belonging to three different triazolato ligands, and a chlorine atom. The Fe—N bond lengths are in the range of 1.998–2.022 Å, very close to each other. The Fe—Cl bond length is 2.238 Å. The bond angles around the iron atom are in the range of 106.47 to 113.23 Å. The polymeric layers as shown in Fig. 2 is formed due to the triply bridging nature of the 1,2,4-triazolato moieties. The 1,2,4-triazolato ligand is simultaneously bound to three different iron atoms through its three nitrogen atoms, and its symmetry is very close to C2v. A layer contains both binuclear units and tetranuclear cavities. In the binuclear unit two iron atoms are bridged by two nearly coplanar triazolato groups through the 1,2-positions, affording a six-membered ring around an inversion center; the Fe···Fe separation within the binuclear unit is equal to 3.781 Å. The chlorine atoms bonded to the metals of a binuclear unit point out in opposite parallel directions. Each binuclear unit is further connected to four parallel units through the four positions of the triazolato groups. Four adjacent units, which are pairwise parallel, afford sixteen-membered tetranuclear cavities. In such a cavity the two nearest neighbor iron atoms are bridged by a single triazolate group through the 1,4 positions with Fe···Fe separations of 5.785 and 6.202 Å.