title: Detaching thiolates from copper and gold clusters: which bonds to break?
abstract: The interaction of alkanethiolates with small coinage metal clusters of copper and gold was studied based on density functional theory with a focus on the metal-thiolate junction. Calculation of fragmentation energies indicate that for Cu(n)-thiolate (n = 1,3,5,7, and 9) there is a progressive lowering in energy for the fragmentation of the S-C bond in the thiolate from a value of 2.9 eV for n = 1 to 1.4 eV for n = 9. The detailed electronic origins of this specific weakening are attributed to a polarization of electron density in the S-C bond as induced by bonding with the Cu(n) cluster. For the gold analogues, this effect is not observed and fragmentation at the S-C bond experiences only a slight 10% destabilization as n increases from 3 to 9. The relativistic origin of this difference between Cu and Au is discussed, and an analysis of bonding considerations is presented.
authors.affiliation: Center for Computational Materials Science, Slovak University of Technology (FEI STU), Ilkovicova 3, 81219, Bratislava, Slovakia. martin.konopka@stuba.sk
authors.forename: Martin
authors.initials: M
authors.lastname: Konôpka
authors.forename: Roger
authors.initials: R
authors.lastname: Rousseau
authors.forename: Ivan
authors.initials: I
authors.lastname: Stich
authors.forename: Dominik
authors.initials: D
authors.lastname: Marx