Transformation of Mononuclear Plutonium(III) Tetrazolate Complexes into Dinuclear Complexes in the Solid State

Abstract

The salt metathesis reaction of Na(pmtz)•H 2 O [pmtz − = 5-(pyrimidyl)tetrazolate] and PuBr 3 •nH 2 O in an aqueous media leads to the formation of the mononuclear compound [Pu(pmtz) 3 (H 2 O) 3 ]•(3 + n) H 2 O (Pu1, n = ∼8) that is isotypic with the lanthanide compounds [Ln(pmtz) 3 (H 2 O) 3 ]•(3 + n) H 2 O (Ln = Ce−Nd). Dissolution and recrystallization of Pu1 in water yields the dinuclear compound {[Pu(pmtz) 2 (H 2 O) 3 ] 2 (μ-pmtz)} 2 (pmtz) 2 •14H 2 O (Pu2), which is isotypic with the lanthanide compounds {[Ln(pmtz) 2 (H 2 O) 3 ] 2 (μ-pmtz)} 2 (pmtz) 2 •14H 2 O (Ln = Nd and Sm). Like their nine-coordinate ionic radii, the M−O and M−N bond lengths in Pu1/Pu2 and Nd1/Nd2, respectively, are within error of one another. The Laporte-forbidden 4f → 4f and 5f → 5f transitions are also assigned in the UV−vis−NIR spectra for these f-element tetrazolate coordination compounds.

Investigation of Pressure Effects in the Bimetallic Transplutonium Tetrazolate Complexes [(An(pmtz)2(H2O)3)2(μ-pmtz)]2(pmtz)2·nH2O (An3+ = Cm3+, Bk3+, and Cf3+)

“…) can permit a pronounced MLCT (metal-to-ligand charge transfer), , such as BkBr 6 3– , Bk­(IO 3 ) 3 , Bk 2 [C 6 (CO 2 ) 6 ]­(H 2 O) 8 ·2H 2 O . A similar phenomenon is observed in the recently reported trivalent plutonium-pmtz compounds: [Pu­(pmtz) 3 (H 2 O) 3 ]·(3+ n )­H 2 O ( n ≈ 8) and [(Pu­(pmtz) 2 (H 2 O) 3 ) 2 (μ-pmtz)] 2 (pmtz) 2 ·14H 2 O (Figure S17) at lower energies because of the less negative Pu 3+ /Pu 4+ couple (−0.780 V, HClO 4 vs. S.C.E.)…”