title: Nanoclusters synthesized by synchrotron radiolysis in concert with wet chemistry.
abstract: Wet chemical reduction of metal ions, a common strategy for synthesizing metal nanoparticles, strongly depends on the electric potential of the metal, and its applications to late transition metal clusters have been limited to special cases. Here, we describe copper nanoclusters grown by synchrotron radiolysis in concert with wet chemistry. The local structure of copper aggregates grown by reducing Cu(II) pentanedionate using synchrotron x-ray beam was studied in situ by x-ray absorption spectroscopy. A detailed analysis of the XANES and EXAFS spectra, compared with DFT calculations and full-potential non-muffin-tin multiple scattering calculations, identified the nanocluster as Cu13 with icosahedral symmetry. The novel "charged" nanoclusters tightly bound to electron-donating amido molecules, which formed as a result of photo-induced deprotonation of ligand amines, were stabilized by irradiation. Monodispersive deposition of nanoclusters was enabled by controlling the type and density of "monomers", in remarkable contrast to the conventional growth of metallic nanoparticles.
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oyanagi
authors.affiliation: Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan.
authors.forename: Yuuichi
authors.initials: Y
authors.lastname: Orimoto
authors.affiliation: INFN Laboratori Nazionali di Frascati, c.p. 13, I-00044 Frascati, Italy.
authors.forename: Kuniko
authors.initials: K
authors.lastname: Hayakawa
authors.affiliation: 1] INFN Laboratori Nazionali di Frascati, c.p. 13, I-00044 Frascati, Italy [2] Groupe Théorie, Département Matériaux-Nanosciences, Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes-1, 35042 Rennes cedex, France.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hatada
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Zhihu
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Uehara
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Atsuyuki
authors.initials: A
authors.lastname: Fukano
authors.affiliation: 1] Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology, 807-1 Shuku-machi, Tosu, Saga 841-0052, Japan [2] Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan [3] CREST, Japan Science and Technology Agency, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Maeda