Infrared spectroscopic and thermal analysis of different modifications of calcium valproate

Vibrational spectra of calcium, strontium and barium valproates. Self-assembly of valproate nanostrands in aqueous solution and in the solid state

“…Only the crude (non-recrystallized) samples, obtained from ethanol, were used to record the spectra. In order to obtain information about their structures, we recorded and analyzed in great detail their vibrational (IR and Raman) spectra, which except for the IR data for a few forms of CaVal, 10 have not been reported yet.…”

“…The previous studies on this compound showed 9,10 that it can exist as several forms, of which only compounds of composition Ca(Val) 2 $2H 2 O 9 and Ca(Val) 2 (Hval)$2H 2 O have been mentioned in the literature (in fact, in ref. 10 the composition provided by the producer of the latter compound was cited). The IR spectra of our sample, obtained by crystallization from ethanol, showed that it is identical with the samples obtained by slow evaporation from water, acetonitrile, methanol and acetone, reported by Kalinkova and Hristov.…”

“…The IR spectra of our sample, obtained by crystallization from ethanol, showed that it is identical with the samples obtained by slow evaporation from water, acetonitrile, methanol and acetone, reported by Kalinkova and Hristov. 10 The broad and structured band at 3426 cm À1 in its spectrum can be associated both with the stretches of the moderately strongly hydrogen bonded OH group of the valproic acid and with OH stretches from the water molecule. The spectrum of SrVal contains three weak bands in this spectral region, at 3680, 3310 and 3180 cm À1 (Fig.…”