Premium
Global Minimum‐Energy Structure and Spectroscopic Properties of I 2 .− ⋅ n H 2 O Clusters: A Monte Carlo Simulated Annealing Study
Author(s) -
Pathak Arup Kumar,
Mukherjee Tulsi,
Maity Dilip Kumar
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200900551
Subject(s) - raman spectroscopy , chemistry , cluster (spacecraft) , dimer , monte carlo method , annealing (glass) , spectral line , molecule , aqueous solution , molecular physics , analytical chemistry (journal) , crystallography , materials science , physics , optics , statistics , mathematics , organic chemistry , chromatography , astronomy , computer science , programming language , composite material
The vibrational (IR and Raman) and photoelectron spectral properties of hydrated iodine‐dimer radical‐anion clusters, I 2 .− ⋅ n H 2 O ( n =1–10), are presented. Several initial guess structures are considered for each size of cluster to locate the global minimum‐energy structure by applying a Monte Carlo simulated annealing procedure including spin–orbit interaction. In the Raman spectrum, hydration reduces the intensity of the II stretching band but enhances the intensity of the OH stretching band of water. Raman spectra of more highly hydrated clusters appear to be simpler than the corresponding IR spectra. Vibrational bands due to simultaneous stretching vibrations of OH bonds in a cyclic water network are observed for I 2 .− ⋅ n H 2 O clusters with n ≥3. The vertical detachment energy (VDE) profile shows stepwise saturation that indicates closing of the geometrical shell in the hydrated clusters on addition of every four water molecules. The calculated VDE of finite‐size small hydrated clusters is extrapolated to evaluate the bulk VDE value of I 2 .− in aqueous solution as 7.6 eV at the CCSD(T) level of theory. Structure and spectroscopic properties of these hydrated clusters are compared with those of hydrated clusters of Cl 2 .− and Br 2 .− .