Ag[B(S₂O₇)₂]: The First Transition Metal Borosulfate Featuring Disulfate Groups

Abstract

Hitherto, the structural diversity of transition metal borosulfates has been limited to B−O−S and B−O−B bridges. Ag[B(S2O7)2] represents the very first transition metal borosulfate featuring S−O−S bridges. The compound was synthesized solvothermally in oleum (65 % SO3) and crystallizes in a new structure type in P21/c (no. 14) with Z=4, a=950.7(4) pm, b=960.1(4) pm, c=1173.0(4) pm and β=98.350(11)°. The crystal structure comprises complex anions [B(S2O7)2]− – consisting of a central boron atom and two chelating disulfate groups – and charge balancing Ag+ ions. Vibrational spectroscopy confirms the presence of S−O−S bridges. A thermal decomposition from Ag[B(S2O7)2] towards Ag[B(SO4)2] was monitored by means of thermogravimetric analysis (TGA) and temperature programmed X‐ray diffraction (TPXRD).

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

“…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 , 3c , 3e , 4 , 5 ] and B‐O‐B[ 3i , 6 , 7 , 8 , 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 Loewenstein's rule.…”

Stabilizing the Homopolycation (I4)2+ with a Hexasulfate in (I4)[S6O19] and a Borosulfate in (I4)[B(S2O7)2]2

“…Examples are known, for example, for the alkaline metals and silver in M [B(S 2 O 7 ) 2 ] ( M =Li, Na, K, Ag). [ 35 , 36 , 37 ] and even more recently we reported on two highly untypical heteropoly Au−Cl cations stabilized by [B(S 2 O 7 ) 2 ] 2 − anions. [38] …”

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

“…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. In contrast to alumosilicates, where Al-O-Al bonds are unexpected according to Loewenstein's rule 19 and in violation of Pauling's rules, 20 several so-called unconventional borosulfates with B-O-B 15,[21][22][23][24] and even S-O-S 8,11,[25][26][27] bridges are known. Hitherto, borosulfates with anionic chains are particularly numerous, whereas 3D networks are especially scarce.…”