From abstract: "Bis(di-n-hexylphosphinyl)methane, HDPM, [(C6H13)2P(O)]2CH2, has been studied as an extractant for a variety of metals. HDPM was evaluated as an extractant for uranium(VI) and compared with tri-n-octylphosphine oxide, TOPO, (C8H13)3PO. In nonpolar solvents, HDPM forms a polymeric-like substance with compounds of uranium(VI). Viscosity measurements indicate that the molecular weight of this polymeric-like substance is about 100 times greater than the corresponding complex with TOPO. Polymer formation occurs only when nonpolar solvents are used as diluents for HDPM and is easily avoided by using polar solvents such as 1,2-aichlorobenzene. HDPM forms 1:1 and 2:1 complexes with uranium(VI) nitrate. Equilibrium constants for these complexes as well as that for the 2:1 TOPO complex were calculated and it was shown that the over-all constant is at least ten times larger for the HDPM complex than for the TOPO complex. The effect of concentration of various mineral acids, extractant concentration, temperature, and diluents on the extraction of uranium are discussed."

From introduction: "In order to locate systematic trends of states with a certain angular momentum and parity Jπ in nuclei having constant neutron excess, both the ground state and the level energies will be considered simultaneously: we plot the total nuclear binding energy or nuclidic mass excess of excited states, whereby the ground states appear as a special case. Such a natural correlation of level schemes has been employed before Inglis already in 1953."