Seeding chiral ensembles of prolinated porphyrin derivatives on glass surface: simple and rapid access to chiral porphyrin films

An easy and fast method to achieve chiral porphyrin films on glass is herein reported. The on-surface formation of organized supramolecular architectures with distinctive and remarkable chiroptical features strictly depends on the macrocycles used, the solvent chosen for the casting deposition, and most importantly, on the roughness of the glass slide. Dynamic light scattering studies performed on 10−4–10−6 M porphyrin solutions revealed the presence of small porphyrin aggregates, whose size and number increase depending on the initial concentration. Once transferred on surface, these protoaggregates act as nucleation seeds for the following, self-assembling into larger structures upon solvent evaporation, with a process driven by a fine balance between intermolecular and molecule–substrate interactions. The described method represents a straightforward way to fabricate porphyrin-based chiral surfaces onto a transparent and economic substrate in few minutes. The results obtained can be particularly promising for the development of sensors based on stereoselective optical active films, targeting the detection of chiral analytes of practical relevance, such as the so-called emerging pollutants released in the environment from agrochemical, food, and pharmaceutical manufacturing

Probing the structural organization of a low temperature transition mixture for CO2 capture through spectroscopic and theoretical studies

We investigated a low temperature transition mixture (LTTM) suitable for carbon capture through infrared spectroscopy, differential scanning calorimetry, absorption of CO2 and computational studies. The system, made up of a homogeneous mixture of ethylene glycol, potassium hydroxide and boric acid (3:1:1), is sensitive to temperature changes that affect the viscosity of the solvent and its capacity to exchange CO2 at the interface.The relationship between the LTTM's molecular structure and its ability to capture the gas were investigated in order to optimize the properties of the absorbing material for developing viable and reusable carbon capture systems.The results suggest that a large number of free OH groups is available to ensure an effective CO2 capture through the formation of the organic carbonate, leading to an average absorption of 22 +/- 1 gCO2 /kgsolv at room temperature. Boric acid acts as a catalyst for the carbonate decomposition and ensures the release of CO2 at 60 degrees C.ATR-FTIR measurements proved that the solvent is mostly regenerated after desorption and can thus continue to absorb further CO2 over a large number of cycles, making the system reusable