title: Coordination chemistry of 2,2'-biphenylenedithiophosphinate and diphenyldithiophosphinate with U, Np, and Pu.
abstract: New members of the dithiophosphinic acid family of potential actinide extractants were prepared: heterocyclic 2,2'-biphenylenedithiophosphinic acids of stoichiometry HS2P(R2C12H6) (R = H or (t)Bu). The time- and atom-efficient syntheses afforded multigram quantities of pure HS2P(R2C12H6) in reasonable yields (∼60%). These compounds differed from other diaryldithiophosphinic acid extractants in that the two aryl groups were connected to one another at the ortho positions to form a 5-membered dibenzophosphole ring. These 2,2'-biphenylenedithiophosphinic acids were readily deprotonated to form S2P(R2C12H6)(1-) anions, which were crystallized as salts with tetraphenylpnictonium cations (ZPh4(1+); Z = P or As). Coordination chemistry between [S2P((t)Bu2C12H6)](1-) and [S2P(C6H5)2](1-) with U, Np, and Pu was comparatively investigated. The results showed that dithiophosphinate complexes of U(IV) and Np(IV) were redox stable relative to those of U(III), whereas reactions involving Pu(IV) gave intractable material. For instance, reactions involving U(IV) and Np(IV) generated An[S2P((t)Bu2C12H6)]4 and An[S2P(C6H5)2]4 whereas reactions between Pu(IV) and [S2P(C6H5)2](1-) generated a mixture of products from which we postulated a transient Pu(III) species based on UV-Vis spectroscopy. However, the trivalent Pu[S2P(C6H5)2]3(NC5H5)2 compound is stable and could be isolated from reactions between [S2P(C6H5)2](1-) and the trivalent PuI3(NC5H5)4 starting material. Attempts to synthesize analogous trivalent compounds with U(III) provided the tetravalent U[S2P(C6H5)2]4 oxidation product.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov and University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. ggirolam@illinois.edu.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Macor
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Jessie L
authors.initials: JL
authors.lastname: Brown
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Justin N
authors.initials: JN
authors.lastname: Cross
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov and The University of Iowa, Iowa City, Iowa 52242-1294, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Daly
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Gaunt
authors.affiliation: University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. ggirolam@illinois.edu.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Girolami
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Janicke
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Stosh A
authors.initials: SA
authors.lastname: Kozimor
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Neu
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Angela C
authors.initials: AC
authors.lastname: Olson
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Reilly
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. gaunt@lanl.gov stosh@lanl.gov.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Scott