Near-Infrared Emitters: Stepwise Assembly of Two Heteropolynuclear Clusters with Tunable AgI:ZnII Ratio

详细信息    查看全文

• 作者：Zhi Wang ; Gui-Lin Zhuang ; Yong-Kai Deng ; Zhen-Yu Feng ; Zhao-Zhen Cao ; Mohamedally Kurmoo ; Chen-Ho Tung ; Di Sun
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：May 16, 2016
• 年：2016
• 卷：55
• 期：10
• 页码：4757-4763
• 全文大小：571K
• 年卷期：0
• ISSN：1520-510X

文摘

Two 3d–4d heteropolynuclear clusters with Ag–Zn ratios of 9:2 and 9:4 were stepwise constructed from a robust nonanuclear silver cluster. Their crystal structures consist of a common bucket-shaped [Ag₉(mba)₉]^9– (H₂mba = 2-mercaptobenzoic acid) core with different numbers of Zn^II connected by different exo-oriented carboxylates. Most fascinating is the observation of emission (∼703 nm) in the near-infrared (NIR) region at 300 K that may be compared to the related Ag₉Zn₃ cluster with aliphatic polyamine as auxiliary ligand that emits from the visible (∼580 nm). The shift is associated with the change of ligand field of the 2,2′-bipyridine. The emission intensity and lifetime were dramatically enhanced along with the slight bathochromic shift upon cooling from 300 K to 80 K. The results raise two significant issues: (a) the structural and electronic effects of the secondary metal binding to the metalloligand and the factors influencing the heteropolynuclear cluster assembly and (b) the use of NIR fluorescence, introduced by integrating two luminophores into one heteropolynuclear entity, in detecting free-moving zinc in biological systems both in vivo and in vitro.