The ring opening metathesis polymerization of cyclic allenes is described. Treating the monomers to a Grubbs-type catalyst afforded polymers that featured allenes integrated into their main chains, as confirmed through a range of spectroscopic, chromatographic, and chemical techniques. Acyclic, 1,3-disubstituted allenes were used as chain transfer agents in the aforementioned reactions. These additives not only provided the corresponding end-functionalized polymers but also enabled control over the molecular weights of the polymers produced. The polymers obtained from the ring opening metathesis polymerization reactions were transformed into silyl-containing derivatives using a hydrosilylation-based, post-polymerization modification. A polymerization mechanism was also deduced and proposed to proceed through a process that involved ruthenium vinylidene intermediates and selective chain transfer.

Although dicyanamide (i.e., [N(CN) ] ) has been commonly used to obtain low-viscosity, halogen-free, room-temperature ionic liquids, liquid-crystalline salts containing such anions have remained virtually unexplored. Here we report a series of amphiphilic dicyanamide salts that, depending on their structures and compositions, adopt smectic, columnar, or bicontinuous cubic thermotropic liquid-crystalline mesophases, even at room temperature in some cases. Their thermal properties were explored by polarized light optical microscopy, differential scanning calorimetry, thermogravimetric analysis (including evolved gas analysis), and variable-temperature synchrotron X-ray diffraction. Comparison of the thermal phase characteristics of these new liquid-crystalline salts featuring "V-shaped" [N(CN) ] anions with those of structural analogues containing [SCN] , [BF ] , [PF ] , or [CF SO ] anions indicated that not only the size of the counterion but also its shape should be considered in the development of mesomorphic salts. Collectively, these discoveries may be expected to facilitate the design of thermotropic ionic liquid crystals that form inverted-type bicontinuous cubic and other sophisticated liquid-crystalline phases.