[Ag59(2, 5-DCBT)32]3−: a new cluster and a precursor for three well-known clusters. Issue 24 (5th June 2017)

• Record Type: Journal Article
• Authors: Khatun, Esma; Ghosh, Atanu; Ghosh, Debasmita; Chakraborty, Papri; Nag, Abhijit; Mondal, Biswajit; Chennu, Sudhakar; Pradeep, Thalappil
• Is Part Of: Nanoscale. Volume 9:Issue 24(2017)
• Page Start: 8240
• Page End: 8248
• Publication Date: 2017-06-05
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr01670k
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : We report the synthesis of a new silver cluster, [Ag59 (2, 5-DCBT)32 ] 3− (I ), which acts as a precursor for the synthesis of three well-known silver clusters, [Ag44 (2, 4-DCBT/4-FTP)30 ] 4− (II ), [Ag25 (2, 4-DMBT)18 ] − (III ) and [Ag29 (1, 3-BDT)12 (PPh3 )4 ] 3− (IV ). Abstract : We report the synthesis of a new silver cluster, [Ag59 (2, 5-DCBT)32 ] 3− (I ) (2, 5-DCBT: 2, 5-dichlorobenzenethiol), which acts as a precursor for the synthesis of three well-known silver clusters, [Ag44 (2, 4-DCBT/4-FTP)30 ] 4− (II ) (4-FTP: 4-fluorothiophenol and 2, 4-DCBT: 2, 4-dichlorobenzenethiol), [Ag25 (2, 4-DMBT)18 ] − (III ) (2, 4-DMBT: 2, 4-dimethylbenzenethiol) and [Ag29 (1, 3-BDT)12 (PPh3 )4 ] 3− (IV ) (1, 3-BDT: 1, 3-benzenedithiol and PPh3 : triphenylphosphine). This newly synthesized silver cluster, I, is characterized using UV-vis absorption studies, high resolution electrospray ionization mass spectrometry (ESI MS) and other analytical tools. The optical absorption spectrum shows distinct features which are completely different from the previously reported silver clusters. We perform the rapid transformations ofI to other well-known clustersII, III andIV by reaction with different thiols. The time-dependent UV-vis and ESI MS measurements reveal thatI dissociates into distinct thiolate entities in the presence of thiols and the thiolates recombine to produce different clusters. The conversion mechanism is found to be quite different from the previous reports where it occurs through the initial formation of ligand exchanged products. Here, we also show the synthesis of a different cluster core, [Ag44 (2, 4-DCBT)30 ] 4− (IIa ) using 2, 4-DCBT, a structural isomer of 2, 5-DCBT under the same synthetic conditions used forI . This observation demonstrates the effect of isomeric thiols on controlling the size of silver clusters. The conversion of one cluster to several other clusters under ambient conditions and the effect of ligand structure in silver cluster synthesis give new insights into the cluster chemistry.