Ligand-Based Control of Single-Site vs. Multi-Site Reactivity by a Trichromium Cluster

Amymarie K Bartholomew; Cristin E Juda; Jonathon N Nessralla; Benjamin Lin; SuYin Grass Wang; Yu-Sheng Chen; Theodore A Betley

doi:10.1002/anie.201901599

Ligand-Based Control of Single-Site vs. Multi-Site Reactivity by a Trichromium Cluster

Angew Chem Int Ed Engl. 2019 Apr 16;58(17):5687-5691. doi: 10.1002/anie.201901599. Epub 2019 Mar 27.

Authors

Amymarie K Bartholomew¹, Cristin E Juda², Jonathon N Nessralla³, Benjamin Lin², SuYin Grass Wang⁴, Yu-Sheng Chen⁴, Theodore A Betley²

Affiliations

¹ Department of Chemistry, Columbia University, New York, NY, 10027, USA.
² Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA, 02138, USA.
³ Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
⁴ ChemMatCARS Beamline, The University of Chicago, Advanced Photon Source, Argonne, IL, 60429, USA.

Abstract

The trichromium cluster (^tbs L)Cr₃ (thf) ([^tbs L]^6- =[1,3,5-C₆ H₉ (NC₆ H₄ -o-NSi^t BuMe₂ )₃ ]^6- ) exhibits steric- and solvation-controlled reactivity with organic azides to form three distinct products: reaction of (^tbs L)Cr₃ (thf) with benzyl azide forms a symmetrized bridging imido complex (^tbs L)Cr₃ (μ³ -NBn); reaction with mesityl azide in benzene affords a terminally bound imido complex (^tbs L)Cr₃ (μ¹ -NMes); whereas the reaction with mesityl azide in THF leads to terminal N-atom excision from the azide to yield the nitride complex (^tbs L)Cr₃ (μ³ -N). The reactivity of this complex demonstrates the ability of the cluster-templating ligand to produce a well-defined polynuclear transition metal cluster that can access distinct single-site and cooperative reactivity controlled by either substrate steric demands or reaction media.

Keywords: azides; bridging ligands; chromium complexes; cluster compounds; multi-electron reactivity.

Abstract

Grants and funding