Laser Raman and infrared spectra of tartaric acid crystals

Abstract

A systematic analysis of the IR and Raman spectra of tartaric acid (TA) [HOOC(CHOH),COOH], based on standard frequency correlations, deuteration shift and typical characteristics (with respect to intensity and width) of bands due to different modes, is reported. Almost all the vibrational modes of TA appear with two or more split components. The doublet structure of the vcH, v , and ti::,, modes arises mainly owing to crystallographically distinguishable sites for two identical oscillators. The splitting of other modes (viz. v~-~, BCH, v : : , v: $, , , )and zcooHl originates from differences in the crystallographic fields around the two identical oscillators and resonance interactions between such oscillators. The doublet of 8%: arises mainly from resonance interactions between two identical oscillators of two identical groups in TA.

Apparent and standard partial molar heat capacities and volumes of aqueous tartaric acid and its sodium salts at elevated temperature and pressure

“…The temperature-dependant expressions for V 2 (H 2 Tar(aq)) obtained by fitting equations (8), (12), (13) and (14) are shown in figure 9, along with values from the ''isothermal'' fits and those of other authors. It is interesting to note that, while V 2 (H 2 Tar(aq)) initially increases with increasing temperature, the values do not appear to diverge towards increasingly positive values at elevated temperatures, as has been observed for other aqueous non-electrolytes [1][2][3][4].…”

“…Values of C p;2 from the isothermal fits and recent values reported by Patterson and Woolley [20] are also listed in table 7 for comparison. The values for V 2 (H 2 Tar(aq)) and V 2 (Na 2 Tar(aq)) in table 8 were taken from the global fit of equations (10) and (13). The uncertainty in all the V 2 values is estimated to be less than AE1 cm 3 Á mol À1 for H 2 Tar and AE2 cm 3 Á mol À1 for Na 2 Ta.…”

“…Thermodynamics 36 (2004) 127-140 www.elsevier.com/locate/jct groups and two -COOH groups on a chain of only two alkyl carbons. Several potentiometric and spectroscopic studies have been done on tartaric acid at ambient temperatures to derive ionization constants and enthalpies of ionization [10][11][12][13]. The apparent molar volumes and heat capacities of tartaric acid and its salts near 298.15 K have been determined by Apelblat and Manzurola [14,15], Sijpkes et al [16], Høiland and Vikingstad [17,18] and by our laboratory [19].…”

“…Apparent molar volumes of H 2 Tar(aq) plotted against molality: ( ), (Ã), and (M) are experimental values at T ¼ 298 K, T ¼ 313 K and T ¼ 328 K, respectively, and ( ), (j), (N), and ( r ) are experimental values at T ¼ 377 K, T ¼ 426 K, T ¼ 476 K and T ¼ 529 K, respectively; (-) global fit of equations(8),(12) and(13).…”

NLO crystals of bis[1-(diaminomethylene)thiouron-1-ium] tartate(2−) hemihydrate and deuterated [1-(diaminomethylene)thiouron-1-ium] tartate(−)

“…In addition, the spectra are compared with the spectra of 1-(diaminomethylene)thiourea [15] and of tartaric acid [34][35][36] as well as of tartate(2À) and tartate(À) salts [37][38][39][40][41][42]. The title compounds have several functional and skeletal groups such as three NH 2 (or ND 2 ) C@S, CANAC, NACAN and NACAS groups in the cation and COO À , (COOD), OH or OD, CAC, CACAC and CAH in the anion.…”