Design of UV-Vis-NIR panchromatic crown-phthalocyanines with controllable aggregation

Abstract

Novel magnesium and zinc phthalocyaninates, bearing four lateral electron-rich 15-crown-5-oxanthrene fragments, were synthesized starting from benzo-15-crown-5. Being almost insoluble in common organic solvents, these complexes could be solubilised by interaction with potassium acetate due to the formation of well-defined cofacial supramolecular dimers. A characteristic feature of these dimers is the presence of additional bands in their UV-Vis spectra, which affords the expansion of light absorption region up to ∼750 nm. This new band corresponds to the charge transfer from the peripheral groups to the Pc core, as evidenced by TDDFT calculations. Potassium cations can be reversibly removed from these dimers by [2.2.2]cryptand, resulting in the formation of monodisperse nanoparticles exhibiting absorbances up to 900 nm. This approach can be further used for the fabrication of nanostructured optoelectronic materials based on the synthesized donor-acceptor panchromatic crown-phthalocyanines.

Supramolecular Approach for Enhancing Single‐Molecule Magnet Properties of Terbium(III)‐Phthalocyaninato Double‐Decker Complexes with Crown Moieties

“…[46][47][48][49] Addition of potassium acetate (KOAc) dissolved in am ixture of CHCl 3 and methanol (7:3) induced the formation of ac o-facial dimer ([1 2 K 4 ] 4 + + in Figure 1) with ac haracteristic blue shift in the Qb and (600-700 nm) as well as the Soret band (300-400 nm), as reported previously. [30][31][32][33][34][35]50] This blue shift is typical when an H-aggregate is formed, followedb ye xciton coupling. [30,31,50] As shown in Figure2a, the intensity of the absorption at 670.5 nm decreased and anew absorption at 644.5 nm appeared and becamem ore intensew ith an increase in the amounto fa dded K + ion.…”

“…Crown ethers, first reported by Pedersen, are excellent units for accommodating various positively charged cations including alkali metal ions . Combining crown ether units with planar phthalocyanine ligands has led to functional materials, the color changes of which are vivid in the presence of alkali metal ions because the guest (alkali metal ions) induces aggregation . Ishikawa et al.…”

“…[26][27][28][29] Combining crown ether units with planar phthalocyanine ligands hasl ed to functional materials, the color changes of which are vivid in the presence of alkali metal ions because the guest (alkali metal ions) induces aggregation. [30][31][32][33][34][35][36][37][38][39][40] Ishikawa et al have reported that K + ions induce co-facial dimer formation of Lu III phthalocyaninato double-decker complexes, which have four crown moietieso n one of the phthalocyaninato ligands. [31,36,40] Among doubledecker complexes, the Tb III analogue (TbPc 2 )h as al arge DE and chemical stability.…”

Advances in Tetrapyrrolic Chemistry over 2013-2017 of Research group Headed by Full Member of RAS A. Yu. Tsivadze: Highlights on the Occasion of his Anniversary

“…Design of UV-Vis-NIR panchromatic crownphthalocyanines with controllable aggregation. [24] Figure 22. A molecular chameleon: reversible pH-and cationinduced control of the optical properties of phthalocyanine-based complexes in the visible and near-infrared spectral ranges.…”

“…[23] Reversible formation of supramolecular cation-induced dimers was used as a powerful tool to control aggregation of new class of panchromatic compounds -crown-substituted oxanthrenocyanines (Figure 21). [24] Peculiarities of UVVis spectral properties of these compounds were interpreted by TDDFT calculations and MCD spectroscopy. [25] Novel "molecular chameleons", namely nonperipherally substituted crown-oxanthrenocyanines were synthesized ( Figure 22).…”