Formation of extended polyiodides at large cation templates.
Alexander J BlakeCarlo CastellanoVito LippolisEnrico PoddaMartin SchröderPublished in: Acta crystallographica. Section C, Structural chemistry (2024)
By studying the structures of (μ-1,4,10,13-tetrathia-7,16-diazacyclooctadecane)bis[iodidopalladium(II)] diiodide penta(diiodine), [Pd 2 I 2 (C 12 H 26 N 2 S 4 )](I) 2 ·5I 2 or [Pd 2 I 2 ([18]aneN 2 S 4 )](I) 2 ·(I 2 ) 5 , and 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane triiodide iodide hemipenta(diiodine) dichloromethane monosolvate, C 18 H 38 N 2 O 6 2+ ·I 3 - ·I - ·2.5I 2 ·CH 2 Cl 2 or [H 2 ([2.2.2]cryptand)](I 3 )(I)(I 2 ) 2.5 ·CH 2 Cl 2 , we confirm the structural variety of extended polyiodides achievable upon changing the shape, charge and dimensions of the cation template, by altering the synthetic strategy adopted and/or the experimental conditions. Although it is still often difficult to characterize discrete [I 2m+n ] n- polyiodides higher than I 3 - on the basis of structural parameters, such as I-I bond distances, FT-Raman spectroscopy appears to identify them as aggregates of I 2 , I - and (symmetric or slightly asymmetric) I 3 - building blocks linked by I...I interactions of varying strengths. However, because FT-Raman spectroscopy carries no information about the topological features of extended polyiodides, the two techniques should therefore be applied in combination to enhance the analysis of this kind of compounds.