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Bis(trimethylammonium)hexane diiodide encapsulates iodine from solution and through a gas/solid reaction yielding in a predictable and controllable manner the selective formation of the rare polyiodide species I(-)...I-I...I(-), which matches in length to the chosen dication.

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State-of-the-art density functional theory calculations are here adopted for the investigation of the crystal structure and of the vibrational properties of α, β, γ, and δ phases of poly(vinylidene fluoride) (PVDF), in comparison with IR and Raman measurements. DFT calculations allowed a detailed interpretation of the IR and Raman spectra of α and β phases, giving vibrational assignments useful for qualitative and quantitative characterization of these systems. From a molecular perspective, the computational investigation of the crystal structure and the spectra of PVDF polymorphs helped in clarifying the role of supramolecular dipole-dipole interactions, which indeed modulate the vibrational properties of these systems, indicating also that intermolecular interaction could play a significant role in the modulation of ferroelectric properties. Furthermore, the combined experimental and computational approach allowed us to identify and characterize the thermally and mechanically induced γ phase, shedding light on the far-IR marker bands of this elusive phase of PVDF.

A holistic detection system, in principle sensitive to any molecular species in the vapor phase is proposed. The sensor consists of a polymeric multilayered distributed Bragg reflector made of a perfluorinated polar polymer, Aquivion, and a nonpolar polymer, poly(N‐vinylcarbazole). Alternated layers of the two polymers provide a characteristic optical response that depends on the chemical species intercalating within the structure. Such differences arise from Flory–Huggins polymer–solvent interactions. Then, the presence of polar, nonpolar, and perfluorinated moieties in the structures, potentially, allows sensitivity to any molecular species, providing a detection system with no need for any additional chemical receptors. As a proof of concept, the study demonstrates the sensitivity of the sensor to very diverse classes of molecules in the vapor phase including perfluorinated, nonpolar hydrophobic, and hydrophilic species and the capability to distinguish them, even in binary mixtures. Additionally, a connection between the dynamic temporal response of the sensors and the chemical–physical properties of the analytes, their concentration, and effective diffusion coefficient within the polymer structure is revealed.