Modeling the interactions of phthalocyanines in water: from the Cu(II)-tetrasulphonate to the metal-free phthalocyanine.
A quantum and statistical study on the effects of the ions Cu(2+) and SO(3)(-) in the solvent structure around the metal-free phthalocyanine (H(2)Pc) is presented. We developed an ab initio interaction potential for the system CuPc-H(2)O based on quantum chemical calculations and studied its transferability to the H(2)Pc-H(2)O and [CuPc(SO(3))(4)](4-)-H(2)O interactions. The use of the molecular dynamics technique allows the determination of energetic and structural properties of CuPc, H(2)Pc, and [CuPc(SO(3))(4)](4-) in water and the understanding of the keys for the different behaviors of the three phthalocyanine (Pc) derivatives in water. The inclusion of the Cu(2+) cation in the Pc structure reinforces the appearance of two axial water molecules and second-shell water molecules in the solvent structure, whereas the presence of SO(3)(-) anions implies a well defined hydration shell of about eight water molecules around them making the macrocycle soluble in water. Debye-Waller factors for axial water molecules have been obtained in order to examine the potential sensitivity of the extended x-ray absorption fine structure technique to detect the axial water molecules.
Departamento de Química Física, Universidad de Sevilla, E-41012 Sevilla, Spain.
Elisa I
EI
Martín
Jose M
JM
Martínez
Enrique
E
Sánchez Marcos
D003300:Copper / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D013451:Sulfonic Acids / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D007211:Indoles; D054833:Isoindoles; D013451:Sulfonic Acids; D014867:Water; D003300:Copper; C013647:phthalocyanine