Biobased polycarbonates were synthesized from 1,4:3,6-dianhydro-D-glucitol, 1,4:3,6-dianhydro-L-iditol, and 1,4:3,6-dianhydro-D-mannitol as the principal diols, using different types of carbonyl sources. The (co)polycarbonates resulting from polycondensation reactions in solution using triphosgene consisted of several types of polymer chains with respect to chain topology (e.g., linear or cyclic chains) and end-group structure (e.g., hydroxyl, chloroformate or alkyl chloride end-groups). The introduction of flexible comonomers seemed to increase the amount of cyclic structures in the product mixtures. The melt polymerization of diphenyl carbonate with 1,4:3,6-dianhydrohexitols required high reaction temperatures and led to almost exclusively hydroxy-functional poly(1,4:3,6-dianhydrohexitol carbonate)s. Copolymerizing the 1,4:3,6-dianhydrohexitols with 1,3-propanediol and diphenyl carbonate at high temperature resulted in the partial loss of 1,3-propanediol. On the other hand, by melt polycondensation of 1,4:3,6-dianhydrohexitol-based bis(phenyl carbonate) monomers in combination with primary diols and/or triols, the insertion of the primary alcohols could be achieved in a more controlled way. OH-functional materials were prepared, having suitable molecular weights, T g values, thermal stability, and melt viscosity profiles for (powder) coating applications. These functional biobased (co)polycarbonates were cured with polyisocyanate curing agents, resulting in colorless to pale yellow transparent, glossy coatings with good mechanical performance and solvent resistance.

Benzene-1,3,5-tricarboxamide (BTA) derivatives with one or three phenylalanine octyl ester (PheOct) moieties were synthesized and their supramolecular polymerization and chiral amplification behavior were investigated in mixing experiments between enantiomer pairs and in mixing with another, achiral BTA component. The incorporation of PheOct moieties is shown to have a major impact on the supramolecular self-assembly.

Ethylene oligomerization activities of chromium catalysts stabilized by different dipyrrole-based ancillary ligands, [(Ph 2 C(C 4 H 4 5), have been investigated using different activation methods, and the results have been compared with the commercial Chevron−Phillips ethylene trimerization system. Upon activation with triethylaluminum (TEA), chromium catalysts stabilized by dipyrrole-based ligands 2−5 showed a lower activity and selectivity compared to the Chevron−Phillips trimerization system based on 2,5-dimethylpyrrole (1) as the ancillary ligand. However, unprecedented increases in both activity and selectivity have been observed by carrying out the oligomerization in methylcyclohexane using depleted-methylaluminoxane (DMAO) along with triisobutylaluminum (TIBA) (1:2 ratio) as cocatalyst system under mild conditions, even for the Chevron−Phillips system itself. Well-defined chromium complexes, [(Ph 2 C(C 4 H 3 N) 2 )Cr(Cl)(THF) 3 ] (6) and {[Ph 2 C(C 4 H 3 N)(C 5 H 6 N]Cr(THF)(μ-Cl)} 2 (7), have been synthesized and fully characterized. Upon activating with MAO, catalyst 7 produced a statistical distribution of oligomers, whereas under identical oligomerization conditions catalyst 6/MAO was found to be inactive. The use of MeAlCl 2 as cocatalyst to activate 7 resulted in the switching of the catalyst's behavior from producing a statistical distribution of LAOs to the selective trimerization of ethylene to 1-hexene. The addition of dialkylzinc along with MAO resulted in an unprecedented activity increase.