The First Phosphates of Heptavalent Rhenium

Abstract

ReVIIO2(PO4) and (ReVII2O5)Sio2[Sit2O(PO4)6] were obtained from Re2O7 and P4O10 in sealed silica tubes (250 ≤ ϑ ≤ 400 °C). The crystal structures were solved and refined from X‐ray single crystal data (ReVIIO2(PO4): C2/c, Z = 24, a = 14.403(1) Å, b = 8.414(1) Å, c = 20.647(3) Å, β = 93.165(8)°, T = 123 K, 10352 ind. refl., 218 variables, 24 atoms in asymmetric unit, R1 = 0.041, wR2 = 0.106; (ReVII2O5)Sio2[Sit2O(PO4)6]: P$\bar{1}$, Z = 1, a = 7.8589(3) Å, b = 7.8609(3) Å, c = 10.8311(4) Å, α = 85.312(2)°, β = 73.078(2)°, γ = 60.075(2)°, T = 298 K, 2551 ind. reflections, 174 variables, 22 atoms in asymmetric unit, R1 = 0.078, wR2 = 0.208). The complex crystal structure of ReO2(PO4) can be derived from the ReO3 structure type. The crystal structure of the silicophosphate consists of distorted [Re2O11] dioctahedra (1.69 Å ≤ d(Re–O) ≤ 2.08 Å), [SiIVO6] octahedra, and [Sit2O(PO4)6]12– heteropolyanions. In ReO2(PO4) monomeric perrhenyl ions (ReO2)3+ (∠(Ot,Re, Ot) ≈ 101.5°) are formed. The silicophosphate (Re2O5)Sio2[Sit2O(PO4)6] contains dinuclear (Re2O5)4+ cations. 31P‐MAS‐NMR studies on ReO2(PO4) are in accordance with three independent sites of phosphorus. The results of 31P‐ and 29Si‐MAS‐NMR studies on (Re2O5)Sio2[Sit2O(PO4)6] are in agreement with three crystallographically independent sites for phosphorus and two sites for silicon.

Osmium(IV) pyrophosphate: Synthesis, Crystallization, and Ligand‐Field Analysis of the [OsIVO6] Chromophore

“…For all transition metals, but technetium and osmium, anhydrous phosphates have been known and crystallographically characterized [1][2][3][4][5] for some years. Remarkably, The wide variability of oxidation states of the metal and of the P/M ratio observed for anhydrous rhenium phosphates appears to be particularly noteworthy (Re IV P 2 O 7 , [6] Re V 2 O 3 (P 2 O 7 ), [7] Re VI 2 O 3 (PO 4 ) 2 , [8] Re VII O 2 (PO 4 ) [9] ). In stark contrast, for the neighbouring platinum group metals (PGM) ruthenium, rhodium and iridium anhydrous phosphates are well established only of the trivalent cations (Ru(PO 3 ) 3 , [10,11] RhPO 4 and (Rh(PO 3 ) 3 , [12] Ir(PO 3 ) 3 [13] ).…”