|
|||||
|
|
Study of the stability of aluminium trimeric clusters in aqueous solutions |
|
| Authors: | G. Lanzani A. Sarpola J. Saukkoriipi K. Laasonen C. A. Morrison B. Slater |
| Affiliation: | 1. Thule Institute, University of Oulu , P.O. Box 7300, 90014, Oulu , Finland giorgio.lanzani@oulu.fi;3. Maintpartner Oy, Kemirantie , 67100 , Kokkola , Finland;4. River Basin Management Unit, Finnish Environment Institute (SYKE), Freshwater Centre, The Oulu Office , Oulu , Finland;5. Department of Chemistry , Aalto University , P.O. Box 16100, 00076, Espoo , Finland;6. School of Chemistry and EaSTCHEM Research School, The University of Edinburgh , Joseph Black Building, West Mains Road, Edinburgh , Scotland , EH9 3JJ , UK;7. Kathleen Lonsdale Materials Chemistry, Department of Chemistry , University College London , 20 Gordon Street, London , WC1H 0AJ , UK |
| Abstract: | Ab initio molecular dynamics (AIMD) based on density functional theory has been used to study small aluminium–oxygen complexes in water. Such Al–O clusters have been seen in several recent mass spectrometry studies. In this study, we have focused on trimeric Al–O clusters. The initial very compact trimeric Al–O structures opened up and formed linear Al–O chains. The typical Al–O coordination number in these chain structures was 5. We have performed long (up to 200 ps) AIMD simulations and these chain structures are stable on the nanosecond time scale. We have also studied the reactivity of the Al–O dimer and solvated Al. We found a formation path for the trimeric cluster, which has a action barrier (0.04 eV) and a reaction free energy of ? 0.55 eV. This suggests that the association of a dimer and a monomer Al–O species is fast and thermodynamically a very favourable process. |
| Keywords: | trimeric aluminium complexes constrained molecular dynamics simulations density functional theory electrospray ionisation time-of-flight mass spectroscopy |