Studies on the effects of metal ions and counter anions on the aggregate behaviors of meso-tetrakis(p-sulfonatophenyl)porphyrin by absorption and fluorescence spectroscopy

Spectroscopic investigation on the effect of pairing anions in imidazolium-based ionic liquids on the J-aggregation of meso-tetrakis-(4-sulfonatophenyl)porphyrin in aqueous solution

“…Also it is deduced that BMIMBF 4 at low concentration and NaBF 4 at any concentration tested promote J-aggregation of TPPS. Both ionic species act as balancing or counter ions, locating on the boundary of TPPS monomers of J-aggregates [23,24]. While at high concentration, BMIM þ ions may be apt to associate with each other [25,26] and then break partially the J-aggregates of TPPS due to larger molecular volume, as shown in Scheme 1.…”

“…While at high concentration, BMIM þ ions may be apt to associate with each other [25,26] and then break partially the J-aggregates of TPPS due to larger molecular volume, as shown in Scheme 1. Therefore, a conclusion could be drawn that J-aggregation of TPPS is related with the structure and size of anions besides acidity [27], concentration of TPPS [28], ionic strength [23] and polarity of the solvents [29].…”

A Miniaturized Therapeutic Chromophore for Multiple Metal Pollutant Sensing, Pathological Metal Diagnosis and Logical Computing

“…The spectral difference is further contributed by steric effects with substituents on α, β, meso position of the porphyrin ring72, aggregation73747576 and axial ligation77.…”

The Role of the Counterions in Self-Assembly of J-Aggregates from meso-Aryl Substituted Porphyrin Diacids in Aqueous Solutions

“…[11] The excess negative charge neutralization on the peripheral substituents is provided by the protons abundant in acidic medium, but the presence of the external cations in the solution can significantly change the aggregation kinetics and the final product structure according to the recent observations. [12] Although the main structural features of the resulting J-aggregates seem to be counterion-independent, the kinetic parameters of TPPS self-assembly have appeared to be remarkably influenced both by the medium acidity, the ionic strength and the nature of the counterions. From the kinetic curves presented in Figure 2 one can conclude that the maximum reaction rate and the highest degree of aggregation are observed for the equimolar mixture of 1M H 2 SO 4 with 1M Na 2 SO 4 , while in the more acidic 1M H 2 SO 4 with the same ionic strength the reaction rate is twice lower.…”

“…[10] In the case of 5,10,15,20-tetrakis(4'-sulfonatophenyl)porphyrin (TPPS) there is a clear experimental evidence for the participation of the bridging anions in both J-and H-aggregate structure formation in dichloromethane, [11] while in aqueous solutions such an effect was observed only at the high ionic strength values. [12] Theoretical calculations by means of DFT and TDDFT, supported by the experimental studies performed by Rosa et al [13] have provided a quantum chemical basis for the effect of the size and nature of the hydrogen-bonded acid residues on the structural and spectroscopic properties of meso-tetraphenylporphyrin (ТРР) diacid derivatives in dichloromethane. These calculations suggested a significant impact of the halide lone pairs into the highest occupied molecular orbitals of the [H 2 TPP 2+ ](X -) 2 complex and proposed the charge-transfer covalent interactions to be an important component of the hydrogen bond energy between the pyrrole N-H groups and the halide anions.…”