Tuning Structural and Optical Properties of Thiolate-Protected Silver Clusters by Formation of a Silver Core with Confined Electrons

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• 作者：Lars Gell ; Alexander Kulesza ; Jens Petersen ; Merle I. S. R枚hr ; Roland Mitri膰 ; Vlasta Bona膷i膰-Kouteck媒
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：July 18, 2013
• 年：2013
• 卷：117
• 期：28
• 页码：14824-14831
• 全文大小：566K
• 年卷期：v.117,no.28(July 18, 2013)
• ISSN：1932-7455

文摘

We present a systematic theoretical investigation of the structural and optical properties of thiolate-protected silver clusters with the goal to design species exhibiting strong absorption and fluorescence in the UV鈥搗is spectral range. We show that the optical properties can be tuned by creating systems with different counts of confined electrons within the cluster core. We consider liganded silver complexes with n silver atoms (Ag_n) and x ligands (L_x) in anionic complexes [Ag_nL_x]^{鈭?/sup> with L = SCH₃. Variation of the composition ratio gives rise to systems with (i) zero confined electrons for x = n + 1, (ii) two confined electrons for x = n 鈥?1, and (iii) four confined electrons for x = n 鈥?3. We show that the number of confined electrons within the cluster core and the geometric structure of the latter are responsible for the spectral patterns, giving rise to intense absorption transitions and fluorescence in the visible or even infrared range. Our results open a perspective for the rational design of stable ligand-protected silver cluster chromophores that might find numerous applications in the field of biosensing.}