Near-Infrared Emitters: Stepwise Assembly of Two Heteropolynuclear Clusters with Tunable Ag(I):Zn(II) Ratio.
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.
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Zhi
Z
Wang
College of Chemical Engineering and Materials Science, Zhejiang University of Technology , Hangzhou, 310032, People's Republic of China.
Gui-Lin
GL
Zhuang
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Yong-Kai
YK
Deng
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Zhen-Yu
ZY
Feng
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Zhao-Zhen
ZZ
Cao
Institut de Chimie de Strasbourg, Université de Strasbourg, CNRS-UMR 7177 , 4 Rue Blaise Pascal, 67008 Strasbourg Cedex, France.
Mohamedally
M
Kurmoo
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Chen-Ho
CH
Tung
Key Lab of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China.
Di
D
Sun