IR spectra and structure of H-complexes of DI-(2-ethylhexyl)phosphoric acid with strong hydrogen bonding and proton transfer

Stoyanov, Evgenii S.; Popov, V. M.; Mikhailov, V. A.

doi:10.1007/bf00660254

Cited by 1 publication

(3 citation statements)

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“…However, unlike the HR-TOA system, in which hydrogen bonding with proton transfer takes place, in these systems strong hydrogen bonding without IR Spectroscopy for Examining HR 517 proton transfer occurs. The structure of the associates corresponds to the associate with a (Scheme 3) type structure, in a similar way to the systems of di(2-ethylhexyl)phosphoric acid-TOA, TOPO, TBP [19] and nitric acid-TOA, triisoamylphosphine oxide (TIAPO), TBP in CCl 4 , [20] in which the formation of the Hcomplexes with strong hydrogen bonding was found for all cases, except for the system with TOA wherein hydrogen bonding with proton transfer occurs. Apparently such a difference in the state of the H-complexes is due to the stronger electron-donor properties of the nitrogen atom in the TOA molecule, as compared to that of the sulfur and oxygen atoms in TIBPS, TBP, and TOPO.…”

Section: Ir Spectroscopymentioning

confidence: 98%

“…When strong hydrogen bonding between TOAH + and An -arises, the ν(NH) absorption band appears at 2100 cm -1 . [19] The ν(NH) value of ,2360 cm -1 provides evidence for hydrogen bonding between the trioctyl amine cation and the dithiophosphinate ion in the ion pair [TOAH + ][R -], structure (Scheme 5). The shift of the stretching vibrations of the P¼S band to the low frequency range (from 617 cm -1 for HR to 610 cm -1 for HR+TOA mixture) appears to provide support for the dithiophosphinate ion formation.…”

Section: Ir Spectroscopymentioning

confidence: 99%

“…The latter, apparently, is caused by the formation of the H-complexes with proton transfer and the trioctylamine cation (TOAH + ), which has a characteristic ν(NH) absorption band in the 2100-3120 cm -1 range in the IR absorption spectra. [19,20] The position of this band depends strongly on the degree of polarity of the cation-anion (TOAH + An -) bond. For the more ionic type bond, the ν(NH) absorption band appears at ,3120 cm -1 .…”

Section: Ir Spectroscopymentioning

confidence: 99%

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Investigation of the State of Bis(2,4,4-trimethylpentyl)dithiophosphinic Acid in Nonane in the Presence of Electron-Donor Additives

Grigorieva¹,

Павленко²,

Пашков³

et al. 2010

Solvent Extraction and Ion Exchange

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An IR-spectroscopy method is used to examine the state of nonane diluted bis (2,4,4-trimethylpentyl)dithiophosphinic acid (HR) in the presence of various electrondonor additives (L). Trioctyl amine (TOA), n-octanol, trioctylphosphine oxide (TOPO), tributylphosphate (TBP), and triisobutylphosphine sulfide (TIBPS) were used as additives. The formation of hydrogen bonded complexes (H-complexes) via proton transfer and a [TOAH + ][R -] ion pair was shown to occur in the system containing HR and TOA. For the other additives, except n-octanol, during the formation of the H-complexes, hydrogen bonding without proton transfer takes place. In the HR and n-octanol mixture H-complexes having a structure in which the acid exhibits both proton and electron-donor properties are formed. The concentrations of the monomers (C HR ) and the activity coefficients for the dithiophosphinic acid (γ HR(tot) ) in the presence of the additives were calculated. It was shown that C HR and γ HR(tot) depend essentially on the type of additive and that their values decrease when passing from n-octanol to TOA. The strength of the interaction between HR and L decreases in the series TOA > TOPO > TBP > TIBPS > n-octanol. This series coincides with the basicity series of the additives. An antagonistic effect takes place when zinc is extracted with the HR and L mixture, where L is the trialkyl amine (TAA), the trialkyl phosphine oxide (TAPO), TBP, and n-octanol. A decrease in extraction is observed in the series TAA > TAPO > TBP > n-octanol. This series coincides with the series for decreasing HR activity in the presence of additives. Thus a decrease in the extractant activity resulting from the interaction between HR and L is the determinant factor during zinc extraction with bis(2,4,4-trimethylpentyl)dithiophosphinic acid in the presence of the electron-donor additives.

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Section: Ir Spectroscopymentioning

confidence: 98%

Section: Ir Spectroscopymentioning

confidence: 99%

Section: Ir Spectroscopymentioning

confidence: 99%

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