Polymorphism and optical, magnetic and thermal properties of the either phyllo- or inosilicate-analogous borosulfate Cu[B₂(SO₄)₄]

Abstract

Two polymorphs of the borosulfate Cu[B2(SO4)4] can be selectively prepared by solvothermal syntheses. The crystal structures of inosilicate-analogous α-Cu[B2(SO4)4] (P , no. 2, a = 5.2636(2), b = 7.1449(2), c...

The Unconventional Cadmium Borosulfates Cd[B2O(SO4)3] and Cd4[B2O(SO4)6]

“…Here, the stability increases from SÀ OÀ S via BÀ OÀ S to BÀ OÀ B bridges containing borosulfates. [3,8,9,12,15,27] Since the title compounds were prepared by the thermal decomposition of the conventional borosulfate Cd[B 2 (SO 4 ) 4 ] this provides a detailed case study of the complex thermal decomposition behaviour of such borosulfates.…”

“…Borosulfates are a fast‐growing class of silicate‐analogous materials [1] . Despite the first crystal structure being reported as recently as 2012 [2] there are over 70 borosulfates with known crystal structure up to date [3] . Borosulfates can be classified as silicate‐analogous in two ways: Firstly, they comprise – with rare exceptions showing trigonal planar coordinated boron [4,5] – exclusively corner sharing borate and sulfate tetrahedra.…”

“…[1] Despite the first crystal structure being reported as recently as 2012 [2] there are over 70 borosulfates with known crystal structure up to date. [3] Borosulfates can be classified as silicate-analogous in two ways: Firstly, they comprise -with rare exceptions showing trigonal planar coordinated boron [4,5] exclusively corner sharing borate and sulfate tetrahedra. Secondly, these structures can be considered to comprise supertetrahedra TX 4 formed by a boron atom acting as centre T coordinated tetrahedrally by four SO 4 moieties X as frequently observed in the building unit [B(SO 4 ) 4 ] 5À .…”

Cd[B2(SO4)4] and H2[B2(SO4)4] – a phyllosilicate-analogous borosulfate and its homeotypic heteropolyacid

“…with infinite two dimensional heteropolyanions, only structures with divalent cations have been reported so far. They generally follow the composition M[B 2 (SO 4 ) 4 ] with M = Mg 2+ [15] , Ca 2+ [29] , Co 2+ [17,18] , Ni 2+ [17] , Zn 2+ [30] , Mn 2+ [30] , Cu 2+ [31] . All of these compounds share the structural motif of connected zwölfer and vierer rings, consisting of alternating (BO 4 )-and (SO 4 )-tetrahedra as their heteropolyanion.…”

“…They generally follow the composition M[B 2 (SO 4 ) 4 ] with M = Mg 2+ , 15 Ca 2+ , 29 Co 2+ , 17,18 Ni 2+ , 17 Zn 2+ , 30 Mn 2+ , 30 Cu 2+ . 31 All of these compounds share the structural motif of connected zwölfer and vierer rings, consisting of alternating (BO 4 )-and (SO 4 )-tetrahedra as their heteropolyanion. This set of compounds can be grouped by the adapted crystal structure differing in the location of the cations in the structure.…”