Synthesis and structure of Cu3PO4[1,2,4-triazole]2OH with a hybrid layered structure: A new organically templated copper (II) hydroxyphosphate
Graphical abstract
Introduction
Following the first discovery of microporous aluminophosphates in 1982 [1], [1](a), [1](b), a large number of open framework metal phosphates have been hydrothermally synthesized, in the presence of an organic template. The elimination of the organic molecule moieties in these compounds may lead to new inorganic microporous materials which could not be obtained otherwise. The rational design and synthesis of these metal oxide based organic–inorganic hybrid materials with two or three-dimensional structure are receiving increasing interest in solid-state chemistry owing to their fascinating properties and great potential applications in many fields such as catalysis, material science, electrical conductivity, magnetism, photochemistry, biology and medicine.
Amongst the many structures known to-date, those incorporating d-block transition metal constitute an important group. In recent years, a variety of new compounds with fascinating structural architectures ranging from clusters, chains, layers and open frameworks have been prepared in the presence of organic ‘templates’. Such examples include: zinc [2], nickel [3], iron [4], manganese [5], titanium [6], vanadium [7], copper [8], molybdenum [9], cobalt [10] and tin [11]. A lot of bimetallic phases were also reported: cobalt–molybdenum [12], cobalt–tungsten [13], cobalt–manganese [14], molybdenum–manganese [15], molybdenum–zinc [16].
1,2,4-Triazole and its derivatives are interesting bridging ligands. Various coordination compounds with this group of ligands coordinated to transition metal ions have been described [8], [17], [18], [19]. In this paper, we report on the hydrothermal synthesis and crystal structure determination of a novel copper (II) hydroxy-phosphate with the following formula: Cu3PO4[C2N3H2]2OH for which single crystals have been obtained.
Section snippets
Hydrothermal synthesis and chemical analysis
All chemicals purchased were of reagent grade and used without further purification. The title compound was prepared hydrothermally, under autogenous pressure. In a typical synthesis, 0.51 g (2.98 mmol) of CuCl2·2H2O was first dissolved in 20 mL of H2O. 0.2 g (4.76 mmol) of NaF was then added, followed by 0.27 g (3.91 mmol) of 1,2,4-triazole and 0.72 g of phosphoric acid (H3PO4 85 wt%) under constant stirring. Finally, a KOH solution (0.98 g (17.5 mmol) in 2.75 mL H2O) was poured to the above
Structural description
The distances and angles values concerning the 1,2,4-triazole molecules are those expected for this ligand (Table 3).
The P atom has a rather regular tetrahedral coordination with an average P–O distance of 1.538 Å and an angle of 109.4° (range from 107.4° to 111.4°). The P–O distances are consistent with those typically seen in phosphates without hydrogen bonding [24], [25], [26]. Each vertex (O1 to O4) of the PO4 tetrahedron is coordinated to metallic Cu2+ ions (Table 3). We have calculated
Conclusion
This paper reports on a new organically templated copper hydroxyphosphate Cu3PO4(C2N3H2)2OH, synthesized hydrothermally in the presence of 1,2,4-triazole as the structure directing agent. This compound provides a new example of uncommon structure containing Cu2+ ions embedded in edge-sharing dimers which coalesce in infinite ribbons through corner-sharing connections. Its structural analysis evidences a two-dimensional character for this copper hybrid material which could begin a new series of
Acknowledgements
The authors are grateful to the “Services Communs de Diffractométrie et de Microanalyse” of the University Henri Poincaré of Nancy for access to their equipments and to L. Aranda (IJL) for the thermogravimetry measurements. We are grateful to S. Dahaoui and E. Wenger for their invaluable help when recording the single crystal diffraction data and to Y. Ravaux for the Microprobe analyses.
References (28)
- et al.
J. Solid State Chem.
(2000) - et al.
J. Solid State Chem.
(2004) - et al.
J. Mater. Chem.
(2001) - et al.
Proc Indian Acad. Sci. (Chem. Sci.)
(2003) - et al.
J. Mol. Struct.
(2006) - et al.
Inorg. Chem.
(2000) - et al.
Inorg. Chem. Commun.
(2003) - et al.
J. Mater. Chem.
(2004) - et al.
C. R. Acad. Sci. II
(2008) - et al.
Inorg. Chem. Commun.
(2007)