Abstract:
We argue that l-alanine thiourea (LATU) 1 (J Therm Anal Calorim 112:1059-1066, 2013) l-valine nickel chloride (LVNiC) 2 (J Therm Anal Calorim 108:887-894, 2012) and l-valine thiourea (LVTU) 3 (J Therm Anal Calorim 119:907-913, 2015) reported by Sangeetha et al. are improperly characterized nonlinear optical crystals. A so-called NaBr-added l-alanine crystal (l-ANaBr) 4 reported by Jayanalina et al. (J Therm Anal Calorim 112:1025-1030, 2013) is actually l-alanine. In this letter, we show that compounds 1-4 are not novel crystals and use these as examples to express the necessity of reporting molecular formula for new compounds instead of abbreviations such as LATU, LVNiC, LVTU and l-ANaBr.
