Hydration of inorganic phosphates in crystal lattices and in aqueous solution. An experimental and theoretical study.
B3LYP/6-31G* and 6-311++G** calculations have been carried out in order to study the hydration of phosphates in aqueous media. Optimized geometries and relative stabilities for PO4(-3), HPO(4)-2, H2PO4(-1) have been calculated considering the interaction with one, two, three, four and five discrete water molecules and taking into account the solvent effect by using the self-consistent reaction field theory (Onsager and PCM methods). The role of specific and bulk contributions of solvent effect on the observable properties of phosphate compounds is analysed. Good agreement between theoretical and available experimental results of harmonic vibration frequencies is found. Significant effects on the geometrical and vibrational frequencies are found for those studied phosphate anions. The results presented here provide a first step toward the understanding of the phosphate group as a hydration sensor in lipid bilayers.
Brandán
S A
SA
Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, 4000 Tucumán, Argentina.
Díaz
S B
SB
Picot
R Cobos
RC
Disalvo
E A
EA
Altabef
A Ben
AB
D018360:Crystallography, X-Ray; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014732:Vibration; D014867:Water / Q000737:chemistry*
D010710:Phosphates; D012996:Solutions; D014867:Water