Alkyltin Keggin Clusters Templated by Sodium

Abstract

Abstract Dodecameric (Sn 12 ) and hexameric topologies dominate monoalkyltin–oxo cluster chemistry. Their condensation, triggered by radiation exposure, recently produced unprecedented patterning performance in EUV lithography. A new cluster topology was crystallized from industrial n ‐BuSnOOH, and additional characterization techniques indicate other clusters are present. Single‐crystal X‐ray analysis reveals a β‐Keggin cluster, which is known but less common than other Keggin isomers in polyoxometalate and polyoxocation chemistry. The structure is formulated [NaO 4 (BuSn) 12 (OH) 3 (O) 9 (OCH 3 ) 12 (Sn(H 2 O) 2 )] (β‐NaSn 13 ). SAXS, NMR, and ESI MS differentiate β‐NaSn 13 , Sn 12 , and other clusters present in crude “ n ‐BuSnOOH” and highlight the role of Na as a template for alkyltin Keggin clusters. Unlike other alkyltin clusters that are cationic, β‐NaSn 13 is neutral. Consequently, it stands as a unique model system, absent of counterions, to study the transformation of clusters to films and nanopatterns.