Triple‐Vertex Linkage of (BO₄)‐Tetrahedra in a Borosulfate: Synthesis, Crystal Structure, and Quantum‐Chemical Investigation of Sr[B₃O(SO₄)₄(SO₄H)]

Abstract

Borosulfates are classified as silicate analogue materials. The number of crystallographically characterized compounds is still limited, whereas the structural diversity is already impressive. The anionic substructures of borosulfates exhibit vertex-connected (BO 4 )-and (SO 4 )-tetrahedra, whereas bridging between two (SO 4 )-or even between two (BO 4 )tetrahedra is scarce. The herein presented compound Sr[B 3 O-(SO 4 ) 4 (SO 4 H)] is the first borosulfate with a triple-vertex linkage of three (BO 4 ) tetrahedra via one common oxygen atom. DFT calculations complement the experimental studies. Bader charges (calculated for all atoms) as well as chargedensity calculations give hint to the electron distribution within the anionic substructure and density-of-states calculations support the interpretation of the bonding situation.Mainly, borosulfates are known as glasses. [1] However, elucidation of their crystal structures gained increasing interest for several applications like solid acid polyelectrolytes or NLO materials during the recent years. [2] Up to now, the number of structurally characterized borosulfates is low compared to silicates. Still, the structural diversity is already impressive. The anionic substructures of borosulfates are similar to silicates, exhibiting soro-, neso-, cyclo-, ino-, phyllo-, and tectosilicates like topologies of vertex connected (BO 4 )and (SO 4 )-tetrahedra. [3] Even the formation of S-O-S [3b,c,e, 4, 5] and B-O-B [3i, 6-9] bonds is not uncommon. This finding is in contrast to the structures of alumosilicates, wherein Al-O-Al bonds are not to be expected according to Loewensteins rule. [10] However, also for borosulfates only vertex linkage of two (SO 4 )-or (BO 4 )-tetrahedra, resulting in the formation of (S 2 O 7 )-and (B 2 O 7 )-subunits, is known.

Achieving Short‐Wavelength Phase‐Matching Second Harmonic Generation in Boron‐Rich Borosulfate with Planar [BO3] Units

“…The bonds between sulfur and the terminal oxygen atoms are in the range of 1.449(5)–1.457(4) Å which is shorter than that of S‐O(‐B) bond (1.561(4) Å). These bond lengths are comparable to those of recently reported borates and borosulfates [4a, 16a] . At the same time, the B‐O‐B and S‐O‐S angles inside the [BO 3 ], [BO 4 ] and [SO 4 ] units are in a usual range.…”

Hierarchical Hollow Zinc Oxide Nanocomposites Derived from Morphology‐Tunable Coordination Polymers for Enhanced Solar Hydrogen Production

“…Compared to the pure ZnIn 2 S 4 , the distortion and deformation of the crystal fringes in O‐doped ZnIn 2 S 4 also reveal the structural changes in the hybrid (Supporting Information, Figure S12) [18] . The DFT calculations were conducted to explore the interference of O‐substitution in the lattice on the electronic structure (Supporting Information, Figure S13) [19] . It was discerned from the density of states (DOS) that O‐doped ZnIn 2 S 4 presents a new energy level near the Fermi level compared to the pure ZnIn 2 S 4 , resulting in a reinforced charge density around the valence band maximum (VBM).…”

“…[18] The DFT calculations were conducted to explore the interference of O-substitution in the lattice on the electronic structure (Supporting Information, Figure S13). [19] It was discerned from the density of states (DOS) that O-doped ZnIn 2 S 4 presents a new energy level near the Fermi level compared to the pure ZnIn 2 S 4 , resulting in a reinforced charge density around the valence band maximum (VBM). The orange area in the charge density distribution plane graph reveals a signal corresponding to oxygen doping, which can help to attract more charge carriers to partake in the actual photocatalytic process.…”

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

“…In recent years, interest in borosulfates has been growing steadily, not only due to their structural versatility [1] but also for their potential applications in the fields of solid acid electrolytes and SHG materials. [2][3][4] The anionic substructures of borosulfates are similar to silicates and consist -except for rare cases [4][5][6] -of (SO 4 )-and (BO 4 )-tetrahedra connected via one common vertex, respectively. Accordingly, oligomeric anions like in K 5 [B(SO 4 ) 4 ] [7] , which was the first reported representative, anionic chains [8][9][10][11][12][13][14][15] and layers [16][17][18] as well as extended 3D network structures [2,8] have been presented.…”