Synthesis, crystal structure and characterization of a new optical di-lithium di-phthalate single crystals

Single crystals of a new alkali phthalic complex salt of di-lithium di-phthalate (C32H30Li4O21) (DLDP) were grown by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in a monoclinic system with a centrosymmetric space group having the unit cell parameters; a=17.037(5) Å, b=5.134(5) Å, and c=21.398(5) Å and α=90.000(5)°, β=113.195(5)°, and γ=90.000(5)° with Z=2. The structure has been refined up to a R-value of 0.0828 from 26,248 observed reflections using a three-dimensional X-ray diffraction intensity data. The vibrational structure of the compound confirms the presence of various functional groups in the molecule. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurring in the compound. Thermal stability of the crystal was also studied by simultaneous TGA/DTA analyses. The UV-VIS-NIR spectrum was recorded to study the transmittance properties of the grown crystals. The obtained results are discussed in detail.