Emulating exhalative chemistry: synthesis and structural characterization of ilinskite, Na[Cu5O2](SeO3)2Cl3, and its K-analogue

Abstract

The K-and Na-synthetic analogues of the fumarolic mineral ilinskite have been synthesized by the chemical vapor transport (CVT) reactions method. The A-[Cu 5 O 2 ](SeO 3 ) 2 Cl 3 (A + = K + , Na + ) compounds crystallize in the orthorhombic space group Pnma: a = 18.1691(6) Å, b = 6.4483(2) Å, c = 10.5684(4) Å, V = 1238.19(7) Å 3 , R 1 = 0.018 for 1957 unique reflections with F > 4σ F for K[Cu 5 O 2 ](SeO 3 ) 2 Cl 3 (KI), and a = 17.7489(18) Å, b = 6.4412(6) Å, c = 10.4880(12) Å, V = 1199.0(2) Å 3 , R 1 = 0.049 for 1300 unique reflections with F > 4σ F for Na[Cu 5 O 2 ](SeO 3 ) 2 Cl 3 (NaI). The crystal structures of KI and NaI are based upon the [O 2 Cu 5 ] 6+ sheets consisting of corner-sharing (OCu 4 ) 6+ tetrahedra. The Na-for-K substitution results in the significant expansion of the interlayer space and changes in local coordination of some of the Cu 2+ cations. The A + cation coordination changes from fivefold (for Na + ) to ninefold (for K + ). The CVT reactions method provides a unique opportunity to model physicochemical conditions existing in fumarolic environments and may be used not only to model exhalative processes, but also to predict possible mineral phases that may form in fumaroles. In particular, the K analogue of ilinskite is not known in nature, whereas it may well form from volcanic gases in a K-rich local geochemical environment.

Oxocentered Units in Three Novel Rb‐Containing Copper Compounds Prepared by CVT Reaction Method

“…The presence of oxocentered tetrahedral units in the crystal structures of I – III provides an indirect evidence that polynuclear Cu‐based oxoclusters may serve as forms of Cu transportation in the gaseous phase in CVT reactions, which would explain their occurrence in the crystal structures of phases formed in dry natural and synthetic environments , …”

“…The chemical vapor transport (CVT) reactions is a synthetic method, where the solid is transferred by a transport agent and crystallized at another place due to the temperature difference between source and deposition zones . The CVT method can be used to simulate natural conditions existing in volcanic fumaroles and also provides access to novel Cu compounds, especially those containing oxocentered tetrahedral units . In this paper we report on the syntheses and crystal structures of three novel copper oxocompounds, Rb 4 Cu 4 OCl 10 ( I ), Rb 2 Cu 3 O(SeO 3 ) 2 Cl ( II ), and RbCu 3 (OH)(SeO 3 )Cl 4 (H 2 O) 3 ( III ) obtained using CVT method.…”

Polyoxometalate chemistry at volcanoes: discovery of a novel class of polyoxocuprate nanoclusters in fumarolic minerals

“…Kondinski clusters (M = Fe 3+ , Ti 4+ ) in arsmirandite and lehmannite found in Tolbachik fumaroles provides a useful clue for the targeted synthesis of their analogues under laboratory conditions. As it has been demonstrated previously [49][50][51] , fumarolic minerals with oxocentered cores can be conveniently synthesized using chemical vapor transport techniques. The occurrence of the [M⊂Cu 12 O 8 (AsO 4 ) 8 ] q− nanoclusters in Tolbachik fumaroles testifies that they are stable under high temperatures (500-700 °C) at least in the gaseous and crystalline phases and may as well possess interesting physical and chemical properties.…”

Se–Cl Interactions in Selenite Chlorides: A Theoretical Study

“…Sophiite, α-Zn 2 (SeO 3 )Cl 2 , was first discovered in fumaroles of the Tolbachik volcano, Kamchatka peninsula, Russia [12]. Its β-polymorph was synthesized by chemical transport reactions [45], which has repeatedly been used for simulation of fumarolic mineralization [54]. It is noteworthy that both polymorphs of Zn 2 (SeO 3 )Cl 2 are highly hygroscopic.…”