Giorgi Nicole, Haridasan Rahul Koottanil, Dobrzycki Lukasz M, Abboud Khalil A, Searles Keith
Center for Catalysis, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
Inorg Chem. 2024 Oct 14;63(41):19098-19104. doi: 10.1021/acs.inorgchem.4c02442. Epub 2024 Oct 1.
A bis-dipyrromethane ligand, 4,4'-bis(1,1-bis(3,5-dimethyl-1H-pyrrol-2-yl)ethyl)-1,1'-biphenyl, [H-BDPM-BPh] (), is synthesized via acid-catalyzed electrophilic aromatic substitution of 2,4-dimethylpyrrole with 4,4'-diacetylbiphenyl. Subsequent deprotonation of with -BuLi yields the corresponding Li-salt [Li-BDPM-BPh] (). Transmetalation involving and either CoCl or [Co(HMDS)] (HMDS = -N(Si(CH))) results in dinuclear Co(II) complexes. In the case of CoCl, the formation of the ate-complex 2[Li(THF)][(BDPM-BPh){Co(μ-Cl)Li(THF)}] () is observed where each metal center occupies a tetrahedral geometry with noninteracting metal centers. However, when utilizing [Co(HMDS)], the dinuclear complex 2[Li(THF)][(BDPM-BPh){Co(HMDS)}] () is obtained with the formation of LiHMDS as the product of elimination. The Co metal centers of complex are both three-coordinate and trigonal planar. Displacement of LiHMDS from readily occurs upon treatment with the ylide base, HCPPh, yielding the neutral complex [(BDPM-BPh){Co(HCPPh)}] (). At room temperature, complexes - have magnetically noninteracting metal centers with S = 3/2 spin states.
