Anion and Guest Directed Tetracyclic Macrocycles of Ag<sub>5</sub>L<sub>4</sub> and Ag<sub>6</sub>L<sub>4</sub> with an Arc-Shaped Ligand Containing Pyridine and Benzimidazole Units: Reversal of Anion Selectivity by Guest

2017-10-17T00:00:00Z (GMT) by Avishek Dey Kumar Biradha
An arc shaped tridentate ligand pyridine-3,5-bis­(1-methyl-benzimidazole-2-yl), <b>L</b>, and Ag­(I) were shown to form two isomers of Ag<sub>5</sub><b>L</b><sub>4</sub> and Ag<sub>6</sub><b>L</b><sub>4</sub> templated by ClO<sub>4</sub><sup>–</sup> and CF<sub>3</sub>SO<sub>3</sub><sup>–</sup> anions, respectively, in DCM-MeOH. Further, the Ag<sub>6</sub><b>L</b><sub>4</sub> cluster containing triflate was also found to form in the presence of nitrobenzene, toluene, and <i>p</i>-xylene. Interestingly, the presence of benzonitrile as guest exhibits reversal of anion selectivity that is perchlorate templated Ag<sub>6</sub><b>L</b><sub>4</sub> while triflate templated Ag<sub>5</sub><b>L</b><sub>4</sub>. The guest exchange form the crystalline solid of Ag<sub>6</sub><b>L</b><sub>4</sub> resulted in the solid-to-solid transformation to Ag<sub>5</sub><b>L</b><sub>4</sub>.