Photoinduced Isomerization of [N<sub>2</sub>]<sup>2–</sup> in a Bimetallic Lutetium Complex
Mingbin Yuan, Andrew J. McNeece, Ekaterina A. Dolgopolova, Laura E. Wolfsberg, Eric G. Bowes, Enrique R. Batista, Ping Yang, Alexander S. Filatov, Benjamin L. Davis
Abstract
The first lanthanide dinitrogen photoswitch [(C 5 Me 4 H) 2 (THF)Lu] 2 (μ–η 2:η 2 -N 2 ), 1, is reported. 1 is a unique example of controlled isomerization between side-on and end-on coordination modes of [N 2 ] 2– in a bimetallic lutetium dinitrogen complex that results in photochromism. Near-infrared light (NIR) was used to promote this effect, as evidenced by single X-ray diffraction (XRD) connectivity and Raman data, generating the [N 2 ] 2– end-on bound isomer, [(C 5 Me 4 H) 2 (THF)Lu] 2 (μ–η 1:η 1 -N 2 ), 2 . Although different ligands and coordinating solvents were studied to replicate and control the optical properties in 1/2, only the original configuration with C 5 Me 4 H ligands and THF as the coordinating solvent worked. Supported by the first-principles calculations, the electronic structures along with the mechanistic details of the side-on to end-on isomerization were unraveled. Preliminary reactivity studies show that 2 formed with NIR light reacts with anthracene, generating dihydroanthracene and anthracene dimers, indicating new redox reaction pathways.