Theoretical investigation of dehydration of aquated Al(OH)2+ species in aqueous solution.
Reaction pathways, solvent effects and energy barriers have been investigated for the dehydration processes of aquated Al(OH)(2)(+) species in aqueous solution by density functional calculations using a supermolecule model. The dehydration processes from Al(H(2)O)(4)(OH)(2)(+) to Al(H(2)O)(2)(OH)(2)(+) involve the water exchange on cis-Al(H(2)O)(4)(OH)(2)(+) and dehydration of the following intermediate pentacoordinate Al(H(2)O)(3)(OH)(2)(+). The calculated results indicate that cis-Al(H(2)O)(4)(OH)(2)(+) exchanges water in a dissociative way with an activation energy of 27.7 kJ mol(-1). Loss of coordinated water from hexacoordinate and pentacoordinate Al(OH)(2)(+) is unfavourable by 22.1 and 6.6 kJ mol(-1), respectively, which supports the presence of the stable hexacoordinate Al(H(2)O)(4)(OH)(2)(+) in aqueous solution. Our results also indicate that both the explicit water molecules and bulk water molecules have great influences on the energy barriers, and they can not be neglected.
Qian
Zhaosheng
Z
School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry of China & Key Laboratory of MOE for Life Science, Nanjing University, Nanjing, 210093, People's Republic of China.
Feng
Hui
H
Yang
Wenjing
W
Zhang
Zhenjiang
Z
Wang
Yingjie
Y
Bi
Shuping
S
D000536:Aluminum Hydroxide / Q000737:chemistry*; D003890:Desiccation; D007477:Ions; D008958:Models, Molecular; D012996:Solutions; D014867:Water / Q000737:chemistry*
D007477:Ions; D012996:Solutions; D014867:Water; D000536:Aluminum Hydroxide