Gem-bis(disubstitutedphosphinyl)alkanes—II

The Chemistry of Solvent Extraction

“…Previously calculated values of 0-15-0-20 for the formation constant oftheequimolar complexTBP.HNO3 has been confirmed/ 254 ' 288 ' 289 > 295 > With trioctylphosphine oxide the reported values are 9-l (252> 253) and 10-2, (294) and with tetrahexylmethylene diphosphonate 15-2. (294) The special case of the salting-out of nitric acid by another, independently well-extractable mineral acid has been investigated in considerable detail/ 291, 292, 296 ' 2 "-301 ) The extraction of nitric acid is enhanced by the addition of HC1, HBr, HC10 4 or H 2 S0 4 to the aqueous solution, due to its increased activity.…”

“…Diphosphonates (and pyrophosphates) form two types of complexes, the mono-and disolvates/ 294,330,342) the latter being formed when the extractant is in large excess. Though there is a difference in the extractive capacity of various esters/ 261, 303) the composition of the organic phase complex is invariably M0 2 (N0 3 ) 2 *2S.…”

“…(405) Other metal salts. So, for example, different values of the mean solvation number for U0 2 (C104) 2 have been obtained when HCIO4 or LiC10 4 or NaC10 4 were used as the salting electrolyte/ 294,406) Equally questionable is the solvation number of protactinium(V) derived from slope analysis/ 359 ) Extraction of metals from sulphate solutions is generally poor/ 200) Hafnium fluoride can be extracted from HF-HC10 4 mixed aqueous solutions, but no pure hafnium fluoride complex could be identified in the TBP phase/ 407) This is not the case, however, when niobium and tantalum are extracted from either pure HF of HF-H 2 S0 4 mixtures. So, for example, different values of the mean solvation number for U0 2 (C104) 2 have been obtained when HCIO4 or LiC10 4 or NaC10 4 were used as the salting electrolyte/ 294,406) Equally questionable is the solvation number of protactinium(V) derived from slope analysis/ 359 ) Extraction of metals from sulphate solutions is generally poor/ 200) Hafnium fluoride can be extracted from HF-HC10 4 mixed aqueous solutions, but no pure hafnium fluoride complex could be identified in the TBP phase/ 407) This is not the case, however, when niobium and tantalum are extracted from either pure HF of HF-H 2 S0 4 mixtures.…”

Organische Phosphorverbindungen XXXI. Ein einfaches Verfahren zur Herstellung von Alkylen‐ bzw. Arylen‐ bzw. diphosphiniten und von Bis‐(dialkyl‐ und diaryl‐phosphinyl)‐alkanen

“…Die Reaktion nach G1. 1 gibt gute Ausbeuten an Bis-phosphinyl-alkanen (I), ist aber (I, n = a), aber nicht die Methylen-Verbindungen [4]; diese wurden erst durch die Umsetzung von Bis-dichlorophosphonyl-methan mit GRIGNARD-Ver-2 R,P(O)MgX + X(CH2)nX --f I + 2 MgXCl (2) bindungen (Gl. 3) zuganglich [5].…”

Some bis (dialkylphosphinyl) methanes as solvent extractants

“…(4) in the hopes that it might be a chelating agent and, therefore, an even better reagent than a monodentate ligand. It was found (5,6) that it was indeed a superior extractant for uranium and probably for other .metals. Whether or not it is a chelating agent is still in doubt.…”