Coordination polymers exemplify how crystal engineering holds great promise for control of the arrangement of atoms in space. The “node and spacer” approach developed for the characterization of inorganic compounds in terms of their topology may be extended on metallorganic compounds by utilizing metal ions to serve as nodes and organic molecules as linear spacers for the generation of infinite architectures. This strategy offers great potential for rational design and synthesis of functional materials and nanostructures that find a wide range of applications in science and nanotechnology. The design and investigation of these new inorganic-organic hybrid materials attract tremendous interest, investments and efforts around the world, which has recently been driven by the rapid growth of their practical use, especially in emerging fields such as information storage, green catalysis, energy conversion and storage, sensors, storage and transport of hydrogen. Recently, more attention has been paid to the metal clusters as molecular building blocks (MBB), which can be used as nodes with enhanced variety of coordination algorithms and size compare with single metal ion and give rise to the family of cluster based polymers. Apart from design perspective, multimetallic clusters may introduce their inherent extraordinary physical properties to the polymeric structure. Cluster based polymers may be assembled from predesigned and pre-synthesized MBB [1]. Employing 1,2-bis(4-pyridyl)ethane (bpe) as bridging ligand and m3-oxo trinuclear pivalate cluster [Fe3O(O2CCMe3)6(H2O)3]O2CCMe3·2Me3CCO2H a new iron(III) coordination polymer {[Fe3O(O2CCMe3)6(HCO2)(bpe)] · Me3CCO2H · THF}n (1) has been synthesized and characterized by IR spectroscopy, single crystal X-ray method and thermogravimetric analysis. Crystals 1 are monoclinic, space group P21/n, a = 12.0218(3), b = 31.5039(7), c = 19.0691(8)Å, β = 100.430(3)°, V = 7102.8(4) Å3 and reveals an 1-D zigzag chain which consists of the trinuclear [Fe3O(O2CCMe3)6] clusters linked by 1,2-bis(4pyridyl)ethane spacer organic ligand (Fig.). The chains are running along the b crystallographic axis. In the crystal the chains are packed as rods in parallel/anti-parallel fashions. Each Fe(III) atom is coordinated by an oxygen atom of the central triangle and four oxygen atoms from bridging pivalate ligands. Two of iron atoms are additionally coordinated by nitrogen atoms of 1,2-bis(4-pyridyl)ethane ligand at apical positions and third metal atom is capped by monodentate formato ligand. figureUpon removal neutral solvent molecules 1 reveals the porous structure with large total potential solvent area volume of 2367Å3 (33.3%) per unit cell. Acknowledgement: This study is supported by Supreme Council for Science and Technological Development of R. Moldova, project 09.836.05.02A.

Coordination polymers exemplify how crystal engineering holds great promise for control of the arrangement of atoms in space. The “node and spacer” approach developed for the characterization of inorganic compounds in terms of their topology may be extended on metallorganic compounds by utilizing metal ions to serve as nodes and organic molecules as linear spacers for the generation of infinite architectures. This strategy offers great potential for rational design and synthesis of functional materials and nanostructures that find a wide range of applications in science and nanotechnology. The design and investigation of these new inorganic-organic hybrid materials attract tremendous interest, investments and efforts around the world, which has recently been driven by the rapid growth of their practical use, especially in emerging fields such as information storage, green catalysis, energy conversion and storage, sensors, storage and transport of hydrogen. Recently, more attention has been paid to the metal clusters as molecular building blocks (MBB), which can be used as nodes with enhanced variety of coordination algorithms and size compare with single metal ion and give rise to the family of cluster based polymers. Apart from design perspective, multimetallic clusters may introduce their inherent extraordinary physical properties to the polymeric structure. Cluster based polymers may be assembled from predesigned and pre-synthesized MBB [1]. Employing 1,2-bis(4-pyridyl)ethane (bpe) as bridging ligand and m3-oxo trinuclear pivalate cluster [Fe3O(O2CCMe3)6(H2O)3]O2CCMe3·2Me3CCO2H a new iron(III) coordination polymer {[Fe3O(O2CCMe3)6(HCO2)(bpe)] · Me3CCO2H · THF}n (1) has been synthesized and characterized by IR spectroscopy, single crystal X-ray method and thermogravimetric analysis. Crystals 1 are monoclinic, space group P21/n, a = 12.0218(3), b = 31.5039(7), c = 19.0691(8)Å, β = 100.430(3)°, V = 7102.8(4) Å3 and reveals an 1-D zigzag chain which consists of the trinuclear [Fe3O(O2CCMe3)6] clusters linked by 1,2-bis(4pyridyl)ethane spacer organic ligand (Fig.). The chains are running along the b crystallographic axis. In the crystal the chains are packed as rods in parallel/anti-parallel fashions. Each Fe(III) atom is coordinated by an oxygen atom of the central triangle and four oxygen atoms from bridging pivalate ligands. Two of iron atoms are additionally coordinated by nitrogen atoms of 1,2-bis(4-pyridyl)ethane ligand at apical positions and third metal atom is capped by monodentate formato ligand. figureUpon removal neutral solvent molecules 1 reveals the porous structure with large total potential solvent area volume of 2367Å3 (33.3%) per unit cell. Acknowledgement: This study is supported by Supreme Council for Science and Technological Development of R. Moldova, project 09.836.05.02A.