Reversible Chromism of Tethered Ruthenium(II) Complexes in the Solid State.

Tethered ruthenium(II) complexes [Ru(η 6 :κ 1 -arene:N)Cl 2 ] (where arene:N is 2-aminobiphenyl ( 1 ) and 2-benzylpyridine ( 2 )) can convert into their open-tethered chlorido counterparts [Ru(η 6 -arene:NH)Cl 3 ], 1·HCl and 2·HCl , at room temperature via solid-state reaction in the presence of HCl vapors. The reaction is accompanied by a change in color, is fully reversible, and crystallinity is maintained in both molecular materials. Organoruthenium tethers are presented as nonporous materials capable of capturing and releasing HCl reversibly in the crystalline solid state.