New iron(III) nitrate hydrates: Fe(NO₃)₃·xH₂O withx= 4, 5 and 6

Abstract

Crystals of the title compounds were grown from their hydrous melts or solutions. The crystal structure of iron(III) trinitrate hexahydrate {hexaaquairon(III) trinitrate, [Fe(H(2)O)(6)](NO(3))(3)} is built up from [Fe(H(2)O)(6)](2+) octahedra and nitrate anions connected via hydrogen bonds. In iron(III) trinitrate pentahydrate {pentaaquanitratoiron(III) dinitrate, [Fe(NO(3))(H(2)O)(5)](NO(3))(2)}, one water molecule in the coordination octahedron of the Fe(III) atom is substituted by an O atom of a nitrate group. Iron(III) trinitrate tetrahydrate {triaquadinitratoiron(III) nitrate monohydrate, [Fe(NO(3))(2)(H(2)O)(3)]NO(3)·H(2)O} represents the first example of a simple iron(III) nitrate with pentagonal-bipyramidal coordination geometry, where two bidentate nitrate anions and one water molecule form a pentagonal plane.

Evaluation of the lgnitability Hazards in Remediated Nitrate Salt Waste

“…During recrystallization from an aqueous solution, water molecules in these hydrated metal complexes will typically remain coordinated -i.e., the "waters of hydration" associated with the resulting solid are not just taking up interstitial space in the crystal lattice (moreover, some particularly hygroscopic metal nitrates will crystallize with additional interstitial water molecules -an example is the hydrated iron nitrate Fe(NO3)3·9H2O [Ref. 4,6]) [Ref. 7].…”

Rebuttal of the Existence of Solid Rare Earth Bicarbonates and the Crystal Structure of Holmium Nitrate Pentahydrate

“…Holmium nitrate pentahydrate crystallizes isotypic to all other known rare earth nitrate pentahydrates [1,10] and some further nitrate pentahydrates, like Fe(NO 3 ) 3 ·5H 2 O ( Table 2). [22] Additionally the rare earth nitrate hexahydrates also contain the same isolated coordination units [Ln III (NO 3 ) 3 (H 2 O) 4 ]. [1] Z. Anorg.…”

On the singularity of scandium

“…A selection of crystallographically characterised Sc(III) and (highspin) Fe(III) complex compound pairs containing six-coordinate, ''octahedral'' metal ion centres Co(NO 3 ) 4 ] 81. Whilst Fe(NO 3 ) 3 Á6H 2 O contains octahedral [Fe(H 2 O) 6 ] 3+ ions, the presence of two bidentate nitrates in the coordination sphere of iron means that high-spin Fe(III) in [Fe(H 2 O) 3 (k 2 -NO 3 ) 2 ]NO 3 is seven coordinate 82. However, the analogous [Sc(H 2 O) 4 (k 2 -NO 3 ) 2 ]NO 3 39 has an extra bound water, meaning that scandium is eight coordinate, and indeed nine coordination is found in [Sc(H 2 O) 3 (k 2 -NO 3 ) 3 ](18-crown-6).…”