Another look at organic/metal interfacial interactions: Application of the quantum theory of atoms in molecules

摘要

Ovaj rad dopunjuje naš prethodni rad (P.M. Mitrašinović. Can. J. Chem. 81, 542 (2003)) u kome je, po prvi put u herniji materijala, pokazano da je kvantna teorija atoma u molekulima (KTAUM) vredno sredstvo za proučavanje prirode veza između organskih molekula i metalnih površina sa fizički opravdanih stanovišta. Pošto osobine elektronske gustine na kritičnoj tački hemijske veze pružaju kvantitativne karakteristike te interakcije, mi predlažemo opštu metodologiju za određivanje prirode veza na metalnim površinama proučavajući prdmene kritičnih parametara kao posledice uvećanja veličine kao i menjanja oblika metalnih klastera koji simuliraju pravu povrsinu. Točnije, mi proučavamo adsorpciju akrilonitrila (AN) na klastere od bakra koji poseduju između 9 i 20 atoma, Cu_n (n = 9-14, 16, 18, 20). Priroda hemijske veze je analizirana statističkom ekstrapolacijom rezultata baziranih na toplogiji elektronske gustine. Ovaj novi pristup nije vezan za fizički neopravdane orbitale.%This article supplements our previous study (P.M. Mitrasinovic. Can. J. Chem. 81, 542 (2003)) in which, for the first time in materials chemistry, the quantum theory of atoms in molecules (QTAIM) was fundamentally established as an invaluable tool for the investigation of the interfacial interactions between organic molecules and metallic surfaces from the physically justified standpoints. Because the properties of the electron density at the bond-critical point (BCP) provide quantitative information on the characteristics of a specific bond, we propose a general methodology for the determination of the nature of the interfacial interactions by investigating the changes of the organic/metal bond-critical parameters as consequences of increasing the size and changing the shape of the metal clusters. In particular, we analyze the adsorption of acrylonitrile (AN) on the copper (100) surface by considering model clusters (Cu_n, n = 9-14,16,18,20) for the actual surface. Statistical models with their goodness of fitting the data obtained by use of the topological analysis of the charge density at the AN/Cu_n (n = 9-14,16,18,20) BCPs are reported. In getting these results essentially associated with the electronic properties and reactivity of various copper clusters, no reference to orbitals has been invoked.