Growth and characterisation of a new polymorph of strontium D, l-malate: A metal organic frame work

• Metal co-ordination complexes of dicarboxylic acids have wide range of potential applications.
• Single crystals of a new polymorph of distrontium D, l-dimalatepentahydrate (DSM), is grown by gel technique for the first time.
• The novel 3D polymeric DSM structure is stabilized by intermolecular hydrogen bonds.
• The 3D porous structure improves biological activity, gas adsorption and storage.
• Transparency of DSM in the entire visible region favors optoelectronic applications.
• DSM shows good antibacterial activity.

A new non-centrosymmetricpolymorph of distrontium D, l-dimalatepentahydrate (DSM) with chemical formula Sr2(C4H4O5)2·5H2O is grown by conventional gel method for the first time. Transparent block like crystals were obtained. Single crystal X-ray Diffraction analysis was done to determine the structure and the crystal belongs to triclinic system, P1 space group with cell dimensions a=6.3815(3) Å, b=7.7753(3) Å, c=9.0309(4) Å, α=73.528(2)°, β=75.608(2)°, γ=86.901(2)°. Hydrogen bonding stabilises the three dimensional polymeric crystal structure. Fourier Transform Infrared spectroscopic method was utilised for the analysis of various functional groups present in the complex. The stoichiometry of the complex was confirmed by elemental analysis. Thermal properties of the crystal were studied by TGA/DTA. The optical transparency of the crystal was studied using UV–visible absorption spectra. The optical band gap is found to be 5.39 eV.The biological activity of the complex was screened against different bacteria using the disc-diffusion method. DSM is found to have antibacterial activity against groups of bacteria excluding Escherichia coli.