TY - JOUR
T1 - Formation of Mixed-Valence Luminescent Silver Clusters via Cation-Coupled Electron-Transfer in a Redox-Active Ionic Crystal Based on a Dawson-type Polyoxometalate with Closed Pores
AU - Haraguchi, Naoya
AU - Okunaga, Tomoki
AU - Shimoyama, Yuto
AU - Ogiwara, Naoki
AU - Kikkawa, Soichi
AU - Yamazoe, Seiji
AU - Inada, Miki
AU - Tachikawa, Takashi
AU - Uchida, Sayaka
N1 - Funding Information:
This work was supported by JSPS Grants-in-Aid for Scientific Research JP19H04564 (Coordination Asymmetry), JP16H06440 and 19H04686 (Mixed Anion), JP20H04673 (Soft Crystals), and 20H02750 from MEXT of Japan, and the joint research program No. R02022 of Molecular Photoscience Research Center, Kobe University. Prof. M. Matsuo and Dr. K. Shozugawa (Univ. of Tokyo) are acknowledged for providing access to the ICP instrument. XPS measurements were performed at the Center of Advanced Instrumental Analysis of Kyushu University, and we thank Dr. Yoshinori Miura (Kyushu University) for supporting us with the measurements. XAFS experiments were conducted at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal numbers: 2020A0715 and 2020A1219).
Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/4/26
Y1 - 2021/4/26
N2 - A redox-active ionic crystal based on a Dawson-type polyoxometalate (POM) [α-P2WVI18O62]6− is utilized to form and stabilize small mixed-valence luminescent silver clusters without the aid of protecting ligands at room temperature. A reduced ionic crystal of Cs3H5[Cr3O(OOCH)6(etpy)3]3[α-P2WV5WVI13O62] ⋅ 5H2O (etpy=4-ethylpyridine) is formed by a cation-coupled electron-transfer (CCET) reaction with sodium ascorbate as a reducing reagent to provide electrons and Cs+ as counter cations of POM. Then, silver is introduced via ion-exchange between Cs+ and Ag+ jointly with CCET reaction: X-ray photoelectron spectroscopy and elemental analysis show that the ionic crystal is oxidized via electron-transfer from the POM (W5+) to Ag+, and [Ag01.5AgI1.5]H4.5[Cr3O(OOCH)6(etpy)3]3[α-P2WV3WVI15O62] ⋅ 7H2O is formed. Photoluminescence and X-ray absorption fine structure suggest that the silver species exist as mixed-valence luminescent clusters with an average formula of [Ag4]2+ probably in a tetrahedral geometry.
AB - A redox-active ionic crystal based on a Dawson-type polyoxometalate (POM) [α-P2WVI18O62]6− is utilized to form and stabilize small mixed-valence luminescent silver clusters without the aid of protecting ligands at room temperature. A reduced ionic crystal of Cs3H5[Cr3O(OOCH)6(etpy)3]3[α-P2WV5WVI13O62] ⋅ 5H2O (etpy=4-ethylpyridine) is formed by a cation-coupled electron-transfer (CCET) reaction with sodium ascorbate as a reducing reagent to provide electrons and Cs+ as counter cations of POM. Then, silver is introduced via ion-exchange between Cs+ and Ag+ jointly with CCET reaction: X-ray photoelectron spectroscopy and elemental analysis show that the ionic crystal is oxidized via electron-transfer from the POM (W5+) to Ag+, and [Ag01.5AgI1.5]H4.5[Cr3O(OOCH)6(etpy)3]3[α-P2WV3WVI15O62] ⋅ 7H2O is formed. Photoluminescence and X-ray absorption fine structure suggest that the silver species exist as mixed-valence luminescent clusters with an average formula of [Ag4]2+ probably in a tetrahedral geometry.
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U2 - 10.1002/ejic.202100101
DO - 10.1002/ejic.202100101
M3 - Article
AN - SCOPUS:85102646512
VL - 2021
SP - 1531
EP - 1535
JO - Berichte der deutschen chemischen Gesellschaft
JF - Berichte der deutschen chemischen Gesellschaft
SN - 0365-9496
IS - 16
ER -