title: Effect of axial ligands on the molecular configurations, stability, reactivity, and photodynamic activities of silicon phthalocyanines.
abstract: To demonstrate the effect of axial ligands on the structure-activity relationship, a series of axially substituted silicon phthalocyanines (SiPcs) have been synthesized with changes to the axial ligands. The reactivity of the axial ligand upon shielding by the phthalocyanine ring current, along with their stability, photophysical, and photodynamic therapy (PDT) activities were compared and evaluated for the first time. As revealed by single-crystal XRD analysis, rotation of the axial -OMe ligands was observed in SiPc 3, which resulted in two molecular configurations coexisting synchronously in both the solid and solution states and causing a split of the phthalocyanine α protons in the (1)H NMR spectra that is significantly different from all SiPcs reported so far. The remarkable photostability, good singlet oxygen quantum yield, and efficient in vitro photodynamic activity synergistically show that compound 3 is one of the most promising photosensitizers for PDT.
authors.affiliation: State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100 Shandong (P.R. China).
authors.forename: Liqiang
authors.initials: L
authors.lastname: Luan
authors.forename: Lanlan
authors.initials: L
authors.lastname: Ding
authors.forename: Jiawei
authors.initials: J
authors.lastname: Shi
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Fang
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Ni
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D008024:Ligands; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D026082:Singlet Oxygen / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D007211:Indoles; D008024:Ligands; D017646:Organosilicon Compounds; D017319:Photosensitizing Agents; C082854:silicon phthalocyanine; D026082:Singlet Oxygen
keywords: X-ray diffraction; photochemistry; phthalocyanines; silicon; structure-activity relationships