Photophysical and Photochemical Properties and Aggregation Behavior of Phthalocyanine and Naphthalocyanine Derivatives

Author(s)

de Souza, Thalita F. M. ^[1] ; Antonio, Felipe C. T. ^[1] ; Zanotto, Mateus ^[1] ; Homem-de-Mello, Paula ^[1] ; Ribeiro, Anderson O. ^[1]

Affiliation

^[1] Univ Fed ABC UFABC, Ctr Ciencias Nat & Humanas, Ave Estados 5001, Bloco B, BR-09210170 Santo Andre, SP - Brazil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 29, n. 6, p. 1199-1209, JUN 2018.
• Web of Science Citations: 3

Abstract

The photophysical and photochemical properties of phthalocyanine and naphthalocyanine with similar structures were studied in solution and with density-functional theory (DFT) computational method. The extended π-conjugated system in naphthalocyanines causes a bathochromic shift in UV-Vis, emission and excitation bands, and promotes lesser generation of singlet oxygen in solution when compared to phthalocyanines. Time dependent DFT (TD-DFT) calculations point out the molecular orbitals involved in Q-band transition, corresponding to highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) transition with a concentration of charge along x-axis, while the transition to LUMO+1 is in y-axis direction. The presence of tert-butyl substituents does not affect the molecular orbitals shape, but affect their energies. Aggregation studies in dimethyl sulfoxide (DMSO):water solutions showed that naphthalocyanines studied have more aggregation tendency than the phthalocyanines. DFT studies indicated that stacked-dimers are preferred to rotated-stacked conformation due the interaction between ZnII and nitrogen atom from different monomers. (AU)

• FAPESP's process: 14/18527-8 - Phthalocyanines and Naphthalocyanines: synthesis and characterization of amphiphilic macrocyles for photodynamic therapy
• Grantee: Anderson Orzari Ribeiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/50680-5 - Photosensitization in life sciences
• Grantee: Mauricio da Silva Baptista
• Support Opportunities: Research Projects - Thematic Grants