Infrared spectrum of crystalline and glassy pyrophosphates : preservation of the pyrophosphate group in the glassy structure

FTIR and Raman spectra of the Na2O–CuO–Bi2O3–P2O5 glasses

“…The spectrum of this glass exhibits no band of PO 2 asymmetric stretching vibration and shows the existence of mPO 3 groups indicating that phosphate chains are depolymerized by the incorporation of Bi 3 + through PUOUBi bonds [22,23]. The simultaneous occurrence of the two bands characteristic of the PUOUP bridge may be considered as an indication of the existence of pyrophosphate groups [28]. This is consistent with the O/P ratio, which is equal to 3.5.…”

“…The characteristic features of 50Na 2 O -10Bi 2 O 3 -40P 2 O 5 glass spectrum are the PO 2 symmetric stretching vibration band at 1180 cm À 1 [22,24], the m of P -O À groups (chain terminator) [25] at 1085 and 970 cm À 1 , the m of PO 3 groups (chain end groups) at 1000 cm À 1 [26], the m as of POP groups at 880 cm À 1 [27], the m s of POP groups at 720 cm À 1 [28] and m of deformation modes of P -O À (PO 4 3 À ) groups [22,26,29] at 545 cm À 1 . The spectrum of this glass exhibits no band of PO 2 asymmetric stretching vibration and shows the existence of mPO 3 groups indicating that phosphate chains are depolymerized by the incorporation of Bi 3 + through PUOUBi bonds [22,23].…”

Effects of Temperature and Pressure on ZDDP

“…The present IR study even at highest pressure (18.4 GPa) and temperature (498 K) yielded no new features in the spectral region from 700 to 1,000 cm -1 , where characteristic vibrational modes of polyphosphate chains would have been observed. It has been reported that the P-O-P bridge vibrational frequencies in the shortest polyphosphate, pyrophosphate (P 2 O 7 4-) occurs at 960-900 cm -1 and 800-700 cm -1 corresponding to antisymmetric and symmetric stretchings [15]. The lack of these characteristic IR modes indicates even under extreme pressure and temperature conditions there is no crosslinkage of phosphate groups in ZDDP.…”

Spectrofluorimetric Study on the Weak Interaction between ATP and Nα‐4‐Tosyl‐L‐arginine Methyl Ester Hydrochloride

“…Bands at 1254 and 1105 cm -1 assigned to the anti-symmetric and symmetric stretching modes of the PO 2 group of ATP were shifted to 1250 and 1100 cm -1 respectively. [21][22][23][24][25] The band at 969 cm -1 assigned to the stretching mode of P-O-P was shifted to 955 cm -1 in the adduct. These results indicated the formation of an adduct resulted in lower wave-number shift of P-O group due to the hydrogen bonding.…”