Photosensitive Tin Sulfur Dioxide Complexes with Unexpected Bonding Modes

• Published in: Chemistry : a European journal Vol. 25; no. 22; pp. 5698 - 5707
• Main Authors: Liu, Xing, Liu, Xiao‐Rui
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 17-04-2019
• Subjects: Ablation; Argon; Chemistry; Condensates; Electronic structure; Infrared spectra; IR spectroscopy; Irradiation; Isomerization; matrix isolation; Photochemical reactions; Photochemicals; Photosensitivity; reaction mechanisms; reactive intermediates; Sulfur; Sulfur dioxide; tin; reaction mechanisms; tin; sulfur dioxide; reactive intermediates; matrix isolation; IR spectroscopy
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201806154

Infrared spectra of the matrix‐isolated Sn(η2‐O2S), Sn(η2‐OSO), Sn(η2‐O2S)(η1‐OSO), Sn(η2‐O2S)2, OSn2(η2‐SO), and Sn(μ2‐O2)SnS molecules were observed following laser‐ablated Sn atom reactions with SO2 during condensation in solid argon. The assignments for the major vibrational modes were confirmed by appropriate S18O2 and 34SO2 isotopic shifts and density functional vibrational frequency calculations (B3LYP and BPW91). Interestingly, the mononuclear complexes are interconvertible; that is, irradiation induces the isomerization of Sn(η2‐O2S) and Sn(η2‐O2S)(η1‐OSO) to Sn(η2‐OSO) and Sn(η2‐O2S)2, respectively, and vice versa on annealing. However, there is no evidence of isomerization reaction in between the binuclear molecules OSn2(η2‐SO) and Sn(μ2‐O2)SnS. Bonding in these products is discussed, and the electronic structure changes associated with different bonding types are revealed, which is crucial for the observed photochemical reactions.
What a difference! Sn atom reactions with SO2 were investigated by matrix isolation infrared absorption spectroscopy. The SO2 ligand association induced electronic structure changes and hence the different photochemical behaviors (see figure).