Extraction of cerium(III) by polymer gels swollen with bidentate organophosphorus compounds.

Takeshita, Kenji; Takashima, Yoichi; Matsumoto, Shiro; Yamanaka, Hiromitsu

doi:10.1252/jcej.28.91

Cited by 11 publications

(1 citation statement)

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“…In spite of the relatively high stability of the complexes of TOPO with most cations including H 3 O + , bidentate ligands with another donor, additional to the phosphine oxide group were construed. Prominent among them is the ‘classical’ extraction agent octyl‐phenyl‐ N , N ‐diisobutylcarbamoylmethylphosphine oxide (CMPO) which is still under lively interest38–43 (for the structure of CMPO, see Scheme ). Considering the interesting behavior37 of TOPO with HP, we decided to put CMPO under analogous scrutiny.…”

Section: Introductionmentioning

confidence: 99%

Interaction of hydrated protons with octyl‐phenyl‐N,N‐diisobutylcarbamoylmethyl phosphine oxide (CMPO): NMR and theoretical study

Křı́ž

Dybal

Makrlík

et al. 2011

Magnetic Reson in Chemistry

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Interaction of octyl-phenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO, the 'classical' rare metal extraction agent) with fully ionized hydrated protons (HP) was studied in acetonitrile-d(3) using (1)H, (13)C, (31)P NMR, PFG NMR and magnetic relaxation. The experimental results were confronted with high-precision ab initio DFT calculations. Relative chemical shifts of NMR signals of CMPO (0.01 mol/L) under the presence of HP in the molar ratio β = 0-2.0 mol/mol show binding between CMPO and HP. Self-diffusion measurements using (1)H PFG NMR demonstrate that larger complexes with higher content of CMPO are generally formed at β < 0.75. Analyzing the collective dependence of (13)C and (31)P NMR chemical shifts on β by the use of program LETAGROP, we obtained very good fitting for the assumed coexistence of two complexes (CMPO)(2)·HP (C(2)) and CMPO.HP (C(1)). The logarithms of the respective stabilization constants log K(i) were found to be 7.518 (C(2)) and 4.581 (C(1)). The system dynamics was studied by measuring the transverse (1)H NMR relaxation using CPMG sequence with varying delays t(p) between the π pulses in the mixtures with β = 0.4-0.8. The following exchange correlation times were obtained: τ(10) = 2.35 × 10(-5), τ(20) = 0.82 × 10(-4), τ(21) = 0.45 × 10(-3) s. The DFT calculations support the conclusion that the complexes C(1) and C(2) are the main species in the mixtures of CMPO with HP. They also agree with the NMR and FTIR observation that the main site to which H(3) O(+) is bound is the P=O group, whereas the amide group does not form a strong bond with the ion when excess water molecules are present.

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Section: Introductionmentioning

confidence: 99%