Vibrational spectra of Cu(II) and Co(II) tetrametaphosphates

Thermal, spectral and microscopic studies of water-rich hydrate of the type Mg2KH(PO4)2·15H2O. Thermal transformations

“…In addition, the three spectra (Fig. 7) reveal at least two important main bands: the one in the 980-860 cm −1 region and the other around 760-730 cm −1 , both ascribed to the P-O-P bridged linkage in the condensed phosphates [28,29,33] The higher-wavenumbered bands represent the asymmetric stretching mode, while the lower-wavenumbered bands represent the symmetric ones [28,29]. It is found that the frequency position of these vibrations is mainly affected by the number of the condensed PO 4 tetrahedra and the type of condensation (linear or cyclic), while the influence of the cations is less pronounced [34].…”

“…Due to the complexity of the systems and overlapping of the bands due to P-O vibrations from different configurations it is not possible to assign unambiguously each vibrational band. In the three spectra there are bands in the regions of 1180-920 cm −1 (stretching modes) and 650-450 cm −1 (bending modes) which are characteristic for isolated tetrahedral PO 4 groups [32], but the vibrations of the terminal PO 3 and PO 2 species from the different condensed phosphates appear in the same spectral regions [28,29,33,34] so the vibrations of these groups cannot be distinguished. Only the bands around 1230-1200 cm −1 could be mainly assigned to PO 3 and PO 2 species.…”

Soft Synthesis Route and Characterization of Superparamagnetic Mn1/2Fe1/2(H2PO4)2·2H2O and Its Decomposed Product

“…The FT-IR spectra of Mn 1/2 Fe 1/2 (H 2 PO 4 ) 2 ·2H 2 O (Figure a) and MnFeP 4 O 12 (Figure b) are very similar to those of M(H 2 PO 4 ) 2 · 2H 2 O and M 2 P 4 O 12 (M = Mn or Fe), respectively. ,,,,, The band position are shifted to the values between those of individual M(H 2 PO 4 ) 2 · 2H 2 O and M 2 P 4 O 12 (M = Mn or Fe), and sharp or weak bands are observed, indicating the inserting of different metal cations (Mn and Fe) in the skeleton. Consequently, vibrational bands are identified in relation to the crystal structure in terms of the fundamental vibrating units, H 2 PO 4 − and H 2 O for Mn 1/2 Fe 1/2 (H 2 PO 4 ) 2 ·2H 2 O and [P 4 O 12 ] 4− ion for MnFeP 4 O 12 , and are assigned according to the literature. ,,, It is known that the existence of short OH···O hydrogen bonds in a variety of strongly hydrogen-bonded solids is manifested by the appearance of the characteristic ABC structure of the ν(OH) vibration. Usually, the ABC bands are very broad and consist of many ill-resolved components.…”

Kinetics and Thermodynamics of the Formation of MnFeP4O12

“…FT-IR spectra of Mn 1/2 Fe 1/2 (H 2 PO 4 ) 2 ·H 2 O and its dehydration product (MnFeP 4 O 12 ) are shown in Figure . Vibrational bands are identified in relation to the crystal structure in terms of the fundamental vibrating units, namely, H 2 PO 4 − and H 2 O, for Mn 1/2 Fe 1/2 (H 2 PO 4 ) 2 ·H 2 O and the [P 4 O 12 ] 4− ion for MnFeP 4 O 12 , which are assigned according to the literature. − Vibrational bands of the H 2 PO 4 − ion are observed in the regions of (300 to 500, 700 to 900, 1160 to 900, 840 to 930, 1000 to 1200, and 2400 to 3300) cm −1 . These bands are assigned to the δ(O 2 PO 2 ), γ(POH), δ(POH), ν(PO 2 (H 2 )), ν(PO 2 ), and ν(OH) vibrations, respectively.…”

“…[11][12][13][14][25][26][27] Therefore, all detectable peaks are indexed as the Mn(H 2 PO 4 ) 2 • 2H 2 O and Mn 2 P 4 O 12 compounds with structure in standard data as PDF#350010 and PDF#380314, respectively. These results indicated that the two crystal structures are in the monoclinic system with space group 25 FT-IR spectra of Mn [25][26][27][28] Vibrational bands of the H 2 PO 4 ion are observed in the regions of (300 to 500, 700 to 900, 1160 to 900, 840 to 930, 1000 to 1200, and 2400 to 3300) cm -1…”