Triple-Vertex Linkage of (BO )-Tetrahedra in a Borosulfate: Synthesis, Crystal Structure, and Quantum-Chemical Investigation of Sr[B O(SO ) (SO H)].

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 )- and (SO )-tetrahedra, whereas bridging between two (SO )- or even between two (BO )-tetrahedra is scarce. The herein presented compound Sr[B O(SO ) (SO H)] is the first borosulfate with a triple-vertex linkage of three (BO ) tetrahedra via one common oxygen atom. DFT calculations complement the experimental studies. Bader charges (calculated for all atoms) as well as charge-density calculations give hint to the electron distribution within the anionic substructure and density-of-states calculations support the interpretation of the bonding situation.