Matsuno Sho, Yamashina Masahiro, Sei Yoshihisa, Akita Munetaka, Kuzume Akiyoshi, Yamamoto Kimihisa, Yoshizawa Michito
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
Nat Commun. 2017 Sep 29;8(1):749. doi: 10.1038/s41467-017-00605-5.
Structural determination of inorganic clusters relies heavily on mass spectrometry because of, in most cases, their poor responsivities toward nuclear magnetic resonance, ultraviolet/visible, and infrared analyses. Nevertheless, mass spectrometry analysis of oligosulfurs (S ), which are unique clusters with copious allotropic forms, usually displays their fragment peaks. Here we report that a polyaromatic capsule acts as a supramolecular matrix for the mass determination of the neutral sulfur clusters. Upon encapsulation, molecular ion peaks derived from the host-guest complexes including cyclic S and S clusters are exclusively detected by common electrospray ionization time-of-flight mass spectrometry analysis. Furthermore, mass spectrometry analysis of a cyclic S cluster, which is in situ prepared from two S clusters within the matrix upon light irradiation, is achieved by the same way. The present matrix can remarkably stabilize the otherwise labile S and S clusters in the polyaromatic shell not only under mass spectrometry conditions but also in an ambient solution state.The structures of inorganic clusters are commonly characterized by mass spectrometry (MS), but neutral sulfur clusters heavily fragment under MS conditions, preventing their exact mass determination. Here, the authors successfully perform MS on labile cyclic sulfur clusters by stabilizing them within ionic supramolecular capsules.
由于在大多数情况下，无机团簇对核磁共振、紫外/可见光谱和红外分析的响应性较差，其结构测定在很大程度上依赖于质谱分析。然而，对具有大量同素异形体的独特团簇——低聚硫（S ）进行质谱分析时，通常会显示出它们的碎片峰。在此，我们报告一种多芳族胶囊可作为用于测定中性硫团簇质量的超分子基质。在包封后，通过普通的电喷雾电离飞行时间质谱分析专门检测到源自包括环状S和S团簇在内的主客体配合物的分子离子峰。此外，通过相同方法实现了对环状S团簇的质谱分析，该环状S团簇是在光照下由基质内的两个S团簇原位制备的。本基质不仅在质谱条件下，而且在环境溶液状态下，都能显著稳定多芳族壳层中原本不稳定的S和S团簇。无机团簇的结构通常通过质谱（MS）来表征，但中性硫团簇在MS条件下会严重碎片化，从而妨碍其精确质量测定。在此，作者通过将不稳定的环状硫团簇稳定在离子超分子胶囊内，成功地对其进行了MS分析。
