Success in Making Zn+ from Atomic Zn0 Encapsulated in an MFI-Type Zeolite with UV Light Irradiation

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• 作者：Akira Oda ; Hiroe Torigoe ; Atsushi Itadani ; Takahiro Ohkubo ; Takashi Yumura ; Hisayoshi Kobayashi ; Yasushige Kuroda
• 刊名：Journal of the American Chemical Society
• 出版年：2013
• 出版时间：December 11, 2013
• 年：2013
• 卷：135
• 期：49
• 页码：18481-18489
• 全文大小：498K
• 年卷期：v.135,no.49(December 11, 2013)
• ISSN：1520-5126

文摘

For the first time, the paramagnetic Zn⁺ species was prepared successfully by the excitation with ultraviolet light in the region ascribed to the absorption band resulting from the 4s鈥?p transition of an atomic Zn⁰ species encapsulated in an MFI-type zeolite. The formed species gives a specific electron spin resonance band at g = 1.998 and also peculiar absorption bands around 38,000 and 32,500 cm^鈥? which originate from 4s鈥?p transitions due to the Zn⁺ species with paramagnetic nature that is formed in MFI. The transformation process (Zn⁰ 鈫?Zn⁺) was explained by considering the mechanism via the excited triplet state (³P) caused by the intersystem crossing from the excited singlet state (¹P) produced through the excitation of the 4s鈥?p transition of an atomic Zn⁰ species grafted in MFI by UV light. The transformation process was well reproduced with the aid of a density functional theory calculation. The thus-formed Zn⁺ species which has the doublet spin state exhibits characteristic reaction nature at room temperature for an O₂ molecule having a triplet spin state in the ground state, forming an 畏¹ type of Zn²⁺鈥揙₂^{鈥?/sup> species. These features clearly indicate the peculiar reactivity of Zn+ in MFI, whereas Zn0鈥?H+)₂MFI hardly reacts with O₂ at room temperature. The bonding nature of [Zn2+鈥揙₂鈥?/sup>] species was also evidenced by ESR measurements and was also discussed on the basis of the results obtained through DFT calculations.}