Premium
Ligand‐Exchange Processes on Solvated Beryllium Cations. Part III
Author(s) -
Puchta Ralph,
van Eldik Rudi
Publication year - 2008
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200890114
Subject(s) - chemistry , ligand (biochemistry) , activation barrier , activation energy , crystallography , molecule , cluster (spacecraft) , beryllium , solvent , density functional theory , computational chemistry , biochemistry , receptor , organic chemistry , computer science , programming language
Abstract On the basis of DFT calculations (B3LYP/6‐311+G**), the possibility to include solvent effects is considered in the investigation of the H 2 O‐exchange mechanism on [Be(H 2 O) 4 ] 2+ within the widely used cluster approach. The smallest system in the gas phase, [Be(H 2 O) 4 (H 2 O)] 2+ , shows the highest activation barrier of +15.6 kcal/mol, whereas the explicit addition of five H‐bonded H 2 O molecules in [{Be(H 2 O) 4 (H 2 O)}(H 2 O) 5 ] 2+ reduces the barrier to +13.5 kcal/mol. Single‐point calculations applying CPCM (B3LYP(CPCM:H 2 O)/6‐311+G**//B3LYP/6‐311+G**) on [Be(H 2 O) 4 (H 2 O)] 2+ lower the barrier to +9.6 kcal/mol. Optimization of the precursor and transition state of [Be(H 2 O) 4 (H 2 O)] 2+ within an implicit model (B3LYP(CPCM:H 2 O)/6‐311+G** or B3LYP(PCM:H 2 O)/6‐311+G**) reduces the activation energy further to +8.3 kcal/mol but does not lead to any local minimum for the precursor and is, therefore, unfavorable.