6 research outputs found
Polynuclear Silver(I) Triazole Complexes: Ion Conduction and Nanowire Formation in the Mesophase
[[abstract]]Examples of polynuclear metallomesogens are few. Herein,1,2,4-triazole ligands were used to prepare mono- and polynuclear silver(I) triazole metallomesogens. Besides showing an SmA phase in the mesophase, two interesting properties were observed. First, higher ion conductivity is always found for the polynuclear complexes than for the mononuclear complexes with the same anion, an observation contrary to the knowledge that migration of a monomeric cation should be faster than that of a polymeric cation. Second, thermolysis of the polynuclear silver(I) triazole complexes in the assembled mesophase yielded Ag nanowires, in an excellent demonstration of the assembled nature of the polynuclear silver(I) ions in the thermolysis process.[[sponsorship]]MOST[[notice]]補æ£å®Œ
Tetranuclear Silver(I) Clusters Showing High Ionic Conductivity in a Bicontinuous Cubic Mesophase
The
synthesis and characterization of tetranuclear silver triazole metallomesogens,
[Ag<sub>4</sub>(L<sup>4</sup>-C<sub><i>n</i></sub>)<sub>6</sub>]Â[BF<sub>4</sub>]<sub>4</sub> (L<sup>4</sup>-C<sub><i>n</i></sub> = 4-alkyl-1,2,4-triazoles where C<sub><i>n</i></sub> stands for C<sub><i>n</i></sub>H<sub>2<i>n</i>+1</sub> with <i>n</i> = 12, 14, 16, and 18), are reported.
Upon heating, a phase transition sequence of Cr → SmC →
Cub → SmA → isotropic liquid is observed for all of
these compounds. Depending on the alkyl chain length, two types of
cubic phases are found in this series of compounds. Those with shorter
alkyl chains (<i>n</i> = 12 and 14) exhibit a micellar cubic
phase, whereas long alkyl chains (<i>n</i> =16 and 18) show
a bicontinuous cubic phase. Superior ionic conductivity at the bicontinuous
cubic mesophase for [Ag<sub>4</sub>(L<sub>4</sub>-C<sub>16</sub>)<sub>6</sub>]Â[BF<sub>4</sub>]<sub>4</sub> is observed because of the presence
of a three-dimensional ion-transporting channel. Doping a small amount
of AgBF<sub>4</sub> enhances the ionic conduction dramatically, presumably
via promotion of the migration of Ag<sup>I</sup> ions in the channels