Fluorite-related one-dimensional units in natural bismuth oxysulfates: the crystal structures of Bi₁₄O₁₆(SO₄)₅and Bi₃₀O₃₃(SO₄)₉(AsO₄)₂

Abstract

The crystal structures of two new natural Bi oxysulfates with the formula Bi14O16(SO4)5 [labelled new phase I; monoclinic, space group C2, a = 21.658 (4), b = 5.6648 (9), c = 15.092 (3) Å, β = 119.433 (11)° and Z = 2] and Bi30O33(SO4)9(AsO4)2 [labelled new phase II; triclinic, space group P1, a = 5.670 (3), b = 13.9408 (9), c = 22.7908 (18) Å, α = 80.903 (5), β = 82.854 (14), γ = 78.27 (2)° and Z = 1] from the high-temperature fumarole deposit of the La Fossa crater at Vulcano (Aeolian Islands, Italy) are reported. The structures are built up by a combination of fluorite-related Bi-O units and isolated (SO4)(2-) tetrahedra (new phase I) or both (SO4)(2-) and (AsO4)(3-) tetrahedra (new phase II). Owing to the effect of stereoactive lone pairs of Bi(3+), Bi-O units in both the structures can be suitably described in terms of oxo-centered OBi4 tetrahedra. The structure of Bi14O16(SO4)5 is based upon one-dimensional [O16Bi14](10+) ribbons formed by six chains of edge-sharing OBi4 tetrahedra extending along [010]. In the structure of Bi30O33(SO4)9(AsO4)2 the same ribbon type coexists with another one-dimensional ribbon formed by seven chains of edge-sharing OBi4 tetrahedra and with the composition [O17Bi16](14+). Ribbons of the same type are joined by (SO4)(2-) and (AsO4)(3-) tetrahedra along [010] – if a reduced triclinic unit-cell setting is considered – so forming two different (001) slabs which alternate to each other along [001] and are joined by additional (SO4)(2-) tetrahedra. New phase I represents the natural analogues of synthetic Bi14O16(SO4)5, but with an ordered structure model.

Thermessaite-(NH4), (NH4)2AlF3(SO4), a new fumarole mineral from La Fossa crater at Vulcano, Aeolian Islands, Italy

“…3). This order of deposition is also consistent with finding the Bi-sulfates leguernite and balićžunićite at Vulcano fumaroles (Garavelli et al , 2014; Pinto et al , 2014, 2015a, b), as well as with the remarkable formation of the complex chloride–sulfates, which could represent the intermediate stage of the transition from a halide to sulfate assemblage after the intrusion of atmospheric oxygen into the system.

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“…The last thermal crisis, which started at Vulcano, Aeolian Islands, Italy in 1988 and reached a maximum in 1993, was characterised by an intense deposition of interesting and rare sublimate minerals. With the aim of investigating the correlation between the deposition of the mineralogical phases and the fumarole temperature, composition of the gas phase and the volcanic activity, our team began a systematic mineralogical investigation, which since 1994, has led to the discovery of a large variety of rare phases and new minerals (Garavelli, 1994; Garavelli and Vurro, 1994; Ferrara et al , 1995; Coradossi et al , 1996; Borodaev et al , 1998, 2000, 2001, 2003; Vurro et al , 1999; Cheynet et al , 2000; Garavelli et al , 1997, 2003, 2005, 2013, 2014; Pinto et al , 2006a, 2006b, 2006c, 2008, 2011, 2014, 2015a, 2015b; Mitolo et al , 2009, 2011, 2013; Balić-Žunić et al , 2016, 2018 a , 2018 b ). The abundance and variety of minerals described for La Fossa crater fumaroles attracted worldwide interest in the mineralogy of the area.…”

Synthesis, Crystal Structures, Spectroscopic Characterization, and Thermal Analyses of the New Bismuth Sulfates NaBi(SO4)2·H2O and ABi(SO4)2 (A = K, Rb, Cs)

“…These lengths agree with the previously reported bismuth sulfates. [10,11,18,30] The O-S-O bond angles vary from 98.3(2) to 129.6(3)°that reflect the distortion of the sulfate tetrahedra.…”

“…It's worth mentioning that KBiCl 2 (SO 4 ) [3] is the first bismuth chloride sulfate with second-order nonlinear optical effect. ( [13] Bi 2 O 2 (SO 4 ), [14] Bi 2 (SO 4 ) 3 , [15] Bi 26 O 27 (SO 4 ) 12 , [16] [Bi 2 (SO 4 ) 2 (dmso) 8 ](HSO 4 ) 2 , [17] [Bi 14 O 16 ](SO 4 ) 5 , [18] [Bi 2 CoO 3 (SO 4 )], [19] [Bi 12.67 O 14 ](SO 4 ) 5 , [20] alkali metal cations are located between the layers or in the tunnels of the structures, respectively. The differences in the crystal structures of the title compounds can mainly be attributed to the different sizes of the alkali metal cations and their different coordination environments.…”

“…It's worth mentioning that KBiCl 2 (SO 4 ) [ 3 ] is the first bismuth chloride sulfate with second‐order nonlinear optical effect. (C 2 N 2 H 10 ) 3 [Bi 2 (SO 4 ) 6 (H 2 O) 2 ] · 4H 2 O, (C 5 N 2 H 14 )[Bi(SO 4 ) 2 (HSO 4 )(H 2 O)] · H 2 O, (C 6 H 22 N 4 )[Bi 2 (SO 4 ) 5 (H 2 O) 2 ] · 4(H 2 O), [ 13 ] Bi 2 O 2 (SO 4 ), [ 14 ] Bi 2 (SO 4 ) 3 , [ 15 ] Bi 26 O 27 (SO 4 ) 12 , [ 16 ] [Bi 2 (SO 4 ) 2 (dmso) 8 ](HSO 4 ) 2 , [ 17 ] [Bi 14 O 16 ](SO 4 ) 5 , [ 18 ] [Bi 2 CoO 3 (SO 4 )], [ 19 ] [Bi 12.67 O 14 ](SO 4 ) 5 , [ 20 ] [Bi 14 O 20 ](SO 4 ), [ 21 ] Bi 4 O 4 (SO 4 )(OH) 2 , [ 22 ] [Bi 6.267 Cu 1.6 O 8 ](SO 4 ) 3 , [ 23 ] and K 3 Bi 2 Cl 5 O 2 (SO 4 ) 2 [ 24 ] exhibit two‐dimensional layered structures.…”