Absorbtion Spectroscopy, Molecular Dynamics Calculations, and Multivariate Curve Resolution on the Phthalocyanine Aggregation

作者：Ajloo Davood^*; Ghadamgahi Maryam; Shaheri Freshte; Zarei Kobra

来源：BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 2014, 35(5): 1440-1448.

DOI：10.5012/bkcs.2014.35.5.1440

• Phthalocyanine
• Solvent effect
• Molecular dynamics simulation
• Multivariate curve resolution
• Spectroscopy

Co(II)-tetrasulfonated phthalocyanine (CoTSP) is known to be aggregated to dimer at high concentration levels in water. A study on the aggregation of CoTSP using multivariate curve resolution analysis of the visible absorbance spectra over a concentration range of 30, 40 and 50 mu M in the presence of dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), acetonitrile (AN) and ethanol (EtOH) in the concentration range of 0 to 3.57 M is conducted. A hard modeling-based multivariate curve resolution method was applied to determine the dissociation constants of the CoTSP aggregates at various temperatures ranging from 25, 45 and 65 degrees C and in the presence of various co-solvents. Dissociation constant for aggregation was increased and then decrease by temperature and concentration of phthalocyanine, respectively. Utilizing the vant Hoff relation, the enthalpy and entropy of the dissociation equilibriums were calculated. For the dissociation of both aggregates, the enthalpy and entropy changes were positive and negative, respectively. Molecular dynamics simulation of co-solvent effect on CoTSP aggregation was done to confirm spectroscopy results. Results of radial distribution RDF), root mean square deviation (RMSD) and distance curves confirmed more effect of polar solvent to decrease monomer formation.

• 出版日期2014-5-20