The nature of the S–S bonds in different compounds. V. The crystal structure of ZnS₂O₄.pyridine

SO2 Activation by the Bis(guanidinato)silylene [iPrNC(NiPr2)NiPr]2Si: Formation of Neutral Six‐Coordinate Silicon(IV) Complexes with a Chelating Sulfito or Dithionito Ligand

“…As also observed for 12 , the exocyclic S–O distances of cis ‐ 13 and trans ‐ 13 [1.379(5)–1.509(5) Å] are significantly shorter than the S–O(Si) distances [1.5575(16)–1.5684(17) Å], again indicating a double bond character of the exocyclic S–O bonds. Compared with a typical single bond (2.08 Å), the S–S distances of cis ‐ 13 and trans ‐ 13 [2.3296(11) Å and 2.3436(11) Å] are remarkably long but compare very well with those of the guanidinato analogues cis ‐ 5 and trans ‐ 5 [2.3359(7) Å] and are also similar to those of the dithionite dianion of Na 2 S 2 O 4 (2.389 Å) and ZnS 2 O 4 · pyridine [2.386(2) Å] . Interestingly, these S–S bond lengths also compare with those reported for molecular complexes of Sn II , Yb III , and U IV with bridging tetradentate dithionito ligands [2.346(2)–2.413(4) Å]…”

Activation of SO2 with [(η5‐C5Me5)2Ln(THF)2] (Ln=Eu, Yb) Leading to Dithionite and Sulfinate Complexes

“…The dithionite anion bridges the two [(η 5 ‐C 5 Me 5 ) 2 Yb] fragments by binding two oxygen atoms to each metal atom (Figure 2). As in [ZnS 2 O 4 ⋅pyridine]5 and [Sn 2 (S 2 O 4 ) 2 ],6 the SS axis lies perpendicular to the YbYb axis. The SS bond length of 2.413(4) Å is in the range of the analogous bond length in [ZnS 2 O 4 ⋅pyridine] (2.39 Å).…”

“…The compounds presented are the first dithionite and sulfinate complexes of the f-elements.The reduction of sulfur dioxide to elemental sulfur (Claus process) [1] or to sodium dithionite [2] are well-established industrial processes. Although sodium dithionite was reported in the 19th century, and its structure was established almost sixty years ago, [3,4] to the best of our knowledge, besides [ZnS 2 O 4 ·pyridine] [5] and [Sn 2 (S 2 O 4 ) 2 ], [6] only two kinds of structurally characterized dithionite transition-metal complexes have been reported. The first kind are [{Rh(C 5 H 4 R)} 2 (m-CH 2 ) 2 (m-O 2 SSO 2 )] (R = Me, Ph, Et, nPr, CH 2 Ph), in which the dithionite ligand is side-on coordinated by both sulfur atoms.…”

“…The remaining reaction mixture consists of 2 and some other products. This mixture was heated at reflux in THF for 48 h. To our surprise, the reaction shifted towards the formation of the sulfinate anion, and the dinuclear tetrasulfinate complex [{(h 5 In conclusion, we have shown that the reaction of SO 2 with [(h 5 -C 5 Me 5 ) 2 Ln(THF) 2 ] (Ln = Eu, Yb) led to two major reaction pathways: 1) reductive coupling of two SO 2 molecules to form a dithionite anion S 2 O 4 2À ; and 2) nucleophilic attack of one ytterbocene C 5 Me 5 ligand to the sulfur atom of SO 2 , thus forming the sulfinate C 5 Me 5 SO 2 À anionic ligand. The formation of the corresponding products (dithionite and sulfinates) depends mainly on the reaction and on the crystallization conditions, as well as on the metal center.…”

Activation of SO2 by [Zn(Cp*)2] and [(Cp*)ZnI–ZnI(Cp*)]

“…Surprisingly, to the best of our knowledge the only other Zn complex containing dithionite ligands is the simple Zn salt, [Zn(S 2 O 4 )(NC 5 H 5 )]. 15 On the other hand, there are multiple examples of Zn sulfite complexes, but they remain a fairly limited class, and most examples feature polymeric arrays. However, related bimetallic complexes such as [Zn(m-SO 3 )(phen)] 2 16 (phen = 1,10-phenanthroline) and…”