FT-IR Spectroscopic and XRD Studies on Tris-Thiourea Strontium Chloride Single Crystals

The synthesized salt was purified by several time re-crystallizations. TTSC single crystals were grown by slow evaporation technique at room temperature. The growth vessel was closed and through a small opening slow evaporation was allowed.

A constant temperature water bath with ± 0.1^oC accuracy was used to maintain the constant temperature. Crystal growth was completed in about 10 days. In the present investigation, the growth of TTSC single crystals by slow evaporation technique at room temperature and its characterization by using FT-IR and powder XRD are reported.

Results and Discussion

FT-IR Study

The FT-IR spectrum of bis-thiourea zinc chloride¹⁴ and zinc tris thiourea sulphate¹⁵ have been reported. The FT-IR spectrum of the grown crystals was recorded in the wave number range 4000-400 cm^-1. Fig. 1 shows the spectrum of the grown crystals.

The C – S stretching vibrations occur at 3277 cm^-1, while the C – S bending occurs at 1083 cm^-1. The N – H primary stretching vibrations occur at 3381 cm^-1 and 3178 cm^-1, while the NH₂ stretching vibrations occur at 1472 cm^-1. The vibrations occurring below 900 cm^-1 may be due to metal and halogen bonding vibrations.

Figure 1: Shows the spectrum of the grown crystals

Click on image to enlarge

Powder XRD Study

The grown crystals have been characterized by powder X-ray diffractometer. Fig. 2 represents the powder X-ray pattern of the grown crystals.

Using powder X computer software the h, k and l parameters as well as d and 2θ values were generated in such a way that these values match with the powder X-ray diffraction pattern. The estimated values of unit cell parameters of TTSC crystals are a = 9.850 A^o, b = 9.700 A^o, c = 18.000 A^o and α = β = γ = 90^o, which shows orthorhombic crystal structure. Earlier workers reported the powder XRD study and estimated the unit cell parameters of bis-thiourea zinc chloride.¹⁴ Orthorhombic form of BTCA was also reported earlier.¹⁶

Figure 2: X-ray pattern of the grown crystals

Click on image to enlarge

Conclusion

TTSC crystals were grown by slow solvent evaporation technique. The grown crystals were characterized by FT-IR spectroscopic and XRD. The FT-IR spectrum of the grown crystals revealed the presence of C – S and N – H bond. From the XRD study of the grown crystal, the estimated values of unit cell parameters of TTSC crystals were found to be a = 9.850 A^o, b = 9.700 A^o, c = 18.000 A^o and α= β = γ = 90^o, which confirmed the orthorhombic crystal structure.

References