A synthetic strategy to control the density of Mn-12 clusters anchored on silicon(100) was investigated. Diluted monolayers suitable for Mn-12 anchoring were prepared by Si-grafting mixtures of the methyl 10-undecylenoate precursor ligand with I-decene spectator spacers. Different ratios of these mixtures were tested. The grafted surfaces were hydrolyzed to reveal the carboxylic groups available for the subsequent exchange with the [Mn12O12- (OAc)(16)(H2O)(4)]-4H(2)O-2AcOH cluster. Modified surfaces were analyzed by attenuated total reflection (ATR)-FTIR spectroscopy, X-ray photoemission spectroscopy (XPS), and AFM imaging. Results of XPS and ATR-FTIR spectroscopy show that the surface mole ratio between grafted ester and decene is higher than in the source solution. The surface density of the Mn-12 cluster is, in turn, strictly proportional to the ester mole fraction. Well-resolved and isolated clusters were observed by AFM, using a diluted ester/ decene 1:1 solution.
Density control of dodecamanganese clusters anchored on silicon(100)
CONDORELLI, Guglielmo Guido;
2006-01-01
Abstract
A synthetic strategy to control the density of Mn-12 clusters anchored on silicon(100) was investigated. Diluted monolayers suitable for Mn-12 anchoring were prepared by Si-grafting mixtures of the methyl 10-undecylenoate precursor ligand with I-decene spectator spacers. Different ratios of these mixtures were tested. The grafted surfaces were hydrolyzed to reveal the carboxylic groups available for the subsequent exchange with the [Mn12O12- (OAc)(16)(H2O)(4)]-4H(2)O-2AcOH cluster. Modified surfaces were analyzed by attenuated total reflection (ATR)-FTIR spectroscopy, X-ray photoemission spectroscopy (XPS), and AFM imaging. Results of XPS and ATR-FTIR spectroscopy show that the surface mole ratio between grafted ester and decene is higher than in the source solution. The surface density of the Mn-12 cluster is, in turn, strictly proportional to the ester mole fraction. Well-resolved and isolated clusters were observed by AFM, using a diluted ester/ decene 1:1 solution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.