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The formation of metal clusters in solution and on biopolymers investigated by first‐principles molecular dynamics
Author(s) -
Colombi Ciacchi L.,
De Vita A.,
Seidel R.,
Mertig M.,
Pompe W.
Publication year - 2003
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200310002
Subject(s) - nucleation , autocatalysis , cluster (spacecraft) , chemical physics , platinum , metal , covalent bond , molecular dynamics , molecule , chemistry , crystallography , computational chemistry , materials science , catalysis , organic chemistry , computer science , programming language
We investigate the molecular mechanisms of platinum cluster nucleation and growth in solution and on biopolymers by means of first‐principles molecular dynamics. In contrast with a classical picture where clusters nucleate by aggregation of metallic Pt(0) atoms, we find that Pt–Pt bonds can form between dissolved Pt(II) complexes already after a single reduction step. Furthermore, we observe that small clusters grow by addition of unreduced PtCl 2 (H 2 O) 2 complexes, consistently with an autocatalytic growth mechanism. Moreover Pt(II) ions covalently bound to biopolymers are found to act as preferred nucleation sites for the formation of clusters. This is a consequence of the strong donor character of the organic ligands which induce the formation of stronger metal‐metal bonds than those obtained in solution. In fact, in metallization experiments we obtain a clean and purely heterogeneous metallization of single DNA molecules leading to thin and uniform Pt cluster chains extended over several microns.