Aggregation of slipped-cofacial phthalocyanine J-type dimers: Spectroscopic and AFM study

Alexander Yu Tolbin; Victor E Pushkarev; Marina V Sedova; Sergey S Maklakov; Larisa G Tomilova

doi:10.1016/j.saa.2018.07.052

Aggregation of slipped-cofacial phthalocyanine J-type dimers: Spectroscopic and AFM study

Spectrochim Acta A Mol Biomol Spectrosc. 2018 Dec 5:205:335-340. doi: 10.1016/j.saa.2018.07.052. Epub 2018 Jul 18.

Authors

Alexander Yu Tolbin¹, Victor E Pushkarev², Marina V Sedova³, Sergey S Maklakov³, Larisa G Tomilova²

Affiliations

¹ Institute of Physiologically Active Compounds, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russian Federation; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation. Electronic address: tolbin@ipac.ac.ru.
² Institute of Physiologically Active Compounds, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russian Federation; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation.
³ Institute for Theoretical and Applied Electrodynamics RAS (ITAE RAS), Izhorskaya St., 13, 125412 Moscow, Russian Federation.

PMID: 30036802
DOI: 10.1016/j.saa.2018.07.052

Abstract

Direct metallation of 2-hydroxyphthalocyanine J-type slipped-cofacial dimeric ligand by Mg, Zn, Cu, Ni and Co salts has been carried out to obtain corresponding metal complexes selectively without any noticeable dissociation or polymerization of the starting ligand. Integrated analysis of aggregation properties in the synthesized series has been conducted with the involvement of AFM microscopy, UV/Vis spectroscopy and theoretical assessment. As a result, a nonlinear relationship between absorption and concentration was found, with aggregation beginning to appear at concentrations above 3.3 × 10^-5 mol L^-1 with predominant formation of trimers from the dimeric molecules in THF solutions.

Keywords: AFM study; Aggregation; Beer's law; Deviation; J-type dimers; Nonlinear absorbance; Phthalocyanine.