Alkyltin Keggin Clusters Templated by Sodium

• Published in: Angewandte Chemie International Edition Vol. 56; no. 34; pp. 10140 - 10144
• Main Authors: Saha, Sumit, Park, Deok‐Hie, Hutchison, Danielle C., Olsen, Morgan R., Zakharov, Lev N., Marsh, David, Goberna‐Ferrón, Sara, Frederick, Ryan T., Diulus, J. Trey, Kenane, Nizan, Herman, Gregory S., Johnson, Darren W., Keszler, Douglas A., Nyman, May
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 14.08.2017
• Edition: International ed. in English
• Subjects: alkyltin clusters; Beta rays; Cluster analysis; Crystallization; Isomers; Keggin clusters; Lithography; nanopatterning; NMR; Nuclear magnetic resonance; Radiation; Radiation effects; Single crystals; Small angle X ray scattering; Sodium; Topology; X ray analysis; X-rays; Keggin clusters; nanopatterning; alkyltin clusters; small-angle X-ray scattering
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201701703

Dodecameric (Sn12) 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 [NaO4(BuSn)12(OH)3(O)9(OCH3)12(Sn(H2O)2)] (β‐NaSn13). SAXS, NMR, and ESI MS differentiate β‐NaSn13, Sn12, 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‐NaSn13 is neutral. Consequently, it stands as a unique model system, absent of counterions, to study the transformation of clusters to films and nanopatterns. Fishing for facts: Solution‐phase characterization of n‐BuSnOOH and structure determination of a neutral sodium‐centered organotin Keggin cluster (β‐NaSn13) extracted from the crude mixture brings new understanding to this widely used compound class. It is a unique model system, absent of counterions, to study the transformation of clusters to films and nanopatterns.