Title

Toward An Understanding Of Ligand Selectivity In Nanocluster Synthesis

Abstract

We performed scalar relativistic density functional theory (DFT) calculations using the projector augmented wave scheme (PAW) to examine the reactivity and selectivity of diphosphine ligands LM, with the formula PH2(CH2)MPH2 (spacer M = 3, 5), toward small-sized cationic Aun (n = 7-11) nanoclusters. By isolating the ligand-induced contribution to the stability condition, we show that such interaction selectively stabilizes the cationic Au11 cluster. Furthermore, we find that L5 with the longer spacer is more capable than L3 of relieving the strain imposed on the spacer by bidentate binding to gold clusters, which have relatively small Au-Au bond lengths. Thus L5 can interact effectively with gold clusters of various sizes, but L3 can do so only with a selected few. This result demonstrates the size-selecting power of L3 toward small gold clusters such as Au113+. To further test the validity of our results we have extended the calculation to a larger cluster, Au 13, and also considered the case of a ligand with a larger spacer, M = 10, interacting with a small cluster (Au3). We find that, for Au13(L3)65+, the strain induced by the stiff L3 spacer causes the gold cluster to disintegrate. We also predict a single-end binding for the interaction of L3 with the gold trimer: one end of the diphosphine is detached from the trimer. Finally, for an ideal, highly selective ligand, we propose a two-body ligand system, in which one part of the ideal ligand provides high reactivity toward the broad range of gold clusters and the other part provides control over the reactivity. The controllable competition between the two components of an ideal, highly selective ligand system will produce a desirable selectivity for the generation of monodisperse nanoclusters of interest through tailoring process. © 2011 American Chemical Society.

Publication Date

8-4-2011

Publication Title

Journal of Physical Chemistry C

Volume

115

Issue

30

Number of Pages

14478-14487

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/jp201723b

Socpus ID

79961078474 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/79961078474

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