The synthesis and properties of a set of novel ionic liquid crystals with congruently shaped cations and anions is reported to check whether pairing mesogenic cations with mesogenic anions leads to a stabilization of a liquid crystalline phase. To that avail 1-alkyl-3-methyltriazolium cations with an alkyl chain length of 10, 12 and 14 carbon atoms have been combined with p-alkyloxy-benzenesulfonate anions with different alkyl chain lengths (n = 10, 12, and 14). The corresponding triazolium iodides have been synthesized as reference compounds where the cation and anion have strong size and shape mismatch. The mesomorphic behavior of all compounds is studied by DSC (differential scanning calorimetry) and POM (polarizing optical microscopy). All compounds except 1-methyl-3-decyltriazolium iodide, which qualifies as an ionic liquid, are thermotropic ionic liquid crystals. All other compounds adopt smectic A phases. A comparison of the thermal phase behavior of the 1-methyl-3-decyltriazolium bromides to the corresponding p-alkoxy-benzensulfonates reveals that definitely the mesophase is stabilized by pairing the rod-shaped 1-alkyl-3-methyltriazolium cation with a rod-like anion of similar size.

In situ crystallization on the diffractometer of 1,1,1,3,3,3hexafluoro-2-propanol (HFIP) with and without pyridine allows to obtain the new polymorphic form II of HFIP and the cocrystal HFIPpyridine. In contrast of the known HFIP form I, single-crystal X-ray diffraction analysis of HFIP form II shows a reduced number of mol-683 ecules in the asymmetric unit (form I: ZЈ = 8, form II: ZЈ = 4) Furthermore, UNI Force Field calculations were used to gain a deeper understanding of the intermolecular potentials of the main interactions of the described crystal structures.

2-cyanopyridine and 4-cyanopyridine were investigated for the controlled synthesis of cocrystals by applying the pK a rule. Cocrystals were designed with oxalic, glutaric and adipic acids and analyzed by single crystal X-ray diffraction. To get a deeper insight into the aggregation behavior of the designed cocrystals, UNI Force Field Calculations were used to compare the intermolecular potentials of the main interactions of the crystal structures.

Functionalized porous materials could play a key role in improving the efficiency of gas separation processes as required by applications such as carbon capture and storage (CCS) and across the hydrogen value chain. Due to the large number of different functionalizations, new experimental approaches are needed to determine if an adsorbent is suitable for a specific separation task. Here, it is shown for the first time that Raman spectroscopy is an efficient tool to characterize the adsorption capacity and selectivity of translucent functionalized porous materials at high pressures, whereby translucence is the precondition to study mass transport inside of a material. As a proof of function, the performance of three silica ionogels to separate an equimolar (hydrogen + carbon dioxide) gas mixture is determined by both accurate gravimetric sorption measurements and Raman spectroscopy, with the observed consistency establishing the latter as a novel measurement technique for the determination of adsorption capacity. These results encourage the use of the spectroscopic approach as a rapid screening method for translucent porous materials, particularly since only very small amounts of sample are required.

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