Exact mass analysis of sulfur clusters upon encapsulation by a polyaromatic capsular matrix

S. Matsuno, M. Yamashina, Y. Sei, M. Akita, A. Kuzume, K. Yamamoto, M. Yoshizawa
Nature Commun. 2017, 8, 749.

硫黄ナノクラスターの精密質量分析法

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_n), 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 S₆ and S₈ clusters are exclusively detected by common electrospray ionization time-of-flight mass spectrometry analysis. Furthermore, mass spectrometry analysis of a cyclic S₁₂ cluster, which is in situ prepared from two S₆ clusters within the matrix upon light irradiation, is achieved by the same way. The present matrix can remarkably stabilize the otherwise labile S₆ and S₁₂ clusters in the polyaromatic shell not only under mass spectrometry conditions but also in an ambient solution state.

化学工業日報「白金クラスター触媒…」

Nature Communications誌に掲載された原子数明確な担持白金クラスターの化学合成の成果に関する記事が9月27日発行の化学工業日報(4面)に掲載されました。
東工大ニュース
Nature Communications

化学工業日報 (2017年9月27日 4面)

Platinum clusters with precise numbers of atoms for preparative-scale catalysis

T. Imaoka, Y. Akanuma, N. Haruta, S. Tsuchiya, K. Ishihara, T. Okayasu, W.-J. Chun, M. Takahashi, K. Yamamoto
Nature Commun. 2017, 8, 688.

原子数明確な白金クラスター担持触媒の大量合成

Subnanometer noble metal clusters have enormous potential, mainly for catalytic applications. Because a difference of only one atom may cause significant changes in their reactivity, a preparation method with atomic-level precision is essential. Although such a precision with enough scalability has been achieved by gas-phase synthesis, large-scale preparation is still at the frontier, hampering practical applications. We now show the atom-precise and fully scalable synthesis of platinum clusters on a milligram scale from tiara-like platinum complexes with various ring numbers (n = 5–13). Low-temperature calcination of the complexes on a carbon support under hydrogen stream affords monodispersed platinum clusters, whose atomicity is equivalent to that of the precursor complex. One of the clusters (Pt₁₀) exhibits high catalytic activity in the hydrogenation of styrene compared to that of the other clusters. This method opens an avenue for the application of these clusters to preparative-scale catalysis.

JST-Leibniz Association Joint Workshop

研究室合宿（長瀞）

長瀞 (埼玉県) へ研究室合宿に行きました。