Comments on the paper “Growth and characterization of semi-organic nonlinear optical crystal: urea thiourea cadmium sulfate”

Bikshandarkoil R Srinivasan,Zbigniew Tylczyński

doi:10.1007/s10973-015-4636-7

Bikshandarkoil R Srinivasan, Zbigniew Tylczyński

Open Access

https://doi.org/10.1007/s10973-015-4636-7

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Abstract

The authors of the title paper (Hanumantharao and Kalainathan in J Therm Anal Calorim 114:239–243, 2013) claim to have grown a novel nonlinear optical urea thiourea cadmium sulfate crystal, represented by no molecular formula but by a code UTCS. Using the title crystal as an example, we wish to express the necessity of reporting molecular formula for new compounds and not abbreviations like UTCS.

Highlights

During the course of a literature survey of metal complexes containing both thiourea and urea ligands, we came across the title paper by Hanumantharao and Kalainathan reporting on the growth of single crystals of ‘urea thiourea cadmium sulfate’ by the slow evaporation method [1]
The authors claim to have characterized ‘urea thiourea cadmium sulfate’ (1) with the aid of single-crystal and powder X-ray diffraction, infrared and UV–visible spectra, thermal studies, etc., no molecular formula is reported in the entire paper for the so-called novel nonlinear optical (NLO) ‘urea thiourea cadmium sulfate crystal’
We believe that the authors named the title crystal based on an incorrect assumption that the slow evaporation of an aqueous solution containing urea, thiourea, and cadmium sulfate in equimolar ratio will result in the formation of a so-called Urea thiourea cadmium sulfate (UTCS) crystal

Summary

Introduction

During the course of a literature survey of metal complexes containing both thiourea and urea ligands, we came across the title paper by Hanumantharao and Kalainathan reporting on the growth of single crystals of ‘urea thiourea cadmium sulfate’ by the slow evaporation method [1]. The authors claim to have characterized ‘urea thiourea cadmium sulfate’ (1) with the aid of single-crystal and powder X-ray diffraction, infrared and UV–visible spectra, thermal studies, etc., no molecular formula is reported in the entire paper for the so-called novel nonlinear optical (NLO) ‘urea thiourea cadmium sulfate crystal’.

Results

Conclusion