American Chemical Society
om700450j_si_005.cif (34.63 kB)

Mn(CO)2 Complexes of Cyclopentadienyl/Scorpionate Hybrid Ligands

Download (34.63 kB)
posted on 2020-04-02, 15:33 authored by Kerstin Kunz, Hannes Vitze, Michael Bolte, Hans-Wolfram Lerner, Matthias Wagner
Rare examples of complexes featuring a chelating cyclopentadienyl/scorpionate hybrid ligand are reported. The compounds are obtained by photolytic decarbonylation of K[(OC)3Mn(C5H4-B(pz)(R)R‘)] (1:  R = R‘ = Me; 2:  R = Me, R‘ = pz; 3:  R = R‘ = pz; pz = pyrazol-1-yl), which leads to the constrained-geometry complexes K[(OC)2Mn(C5H4-B(μ-pz)(R)R‘)] (46) in quantitative yields. In 46, the Mn-coordinating pyrazolyl ring is tethered to the cyclopentadienyl ligand via a borate bridge. According to X-ray crystallography, the molecular frameworks of 46 are largely unstrained. The ligand scaffold is thus well adapted to the coordination requirements of the Mn(I) ion. The crystal lattices of 2, 3, and Li[(OC)3Mn(C5H4-BPh3)] (7) contain dimeric aggregates held together by K+-OC σ adducts, K+-pz σ adducts, and K+-pz π interactions (2, 3) as well as Li+-OC σ adducts and Li+-phenyl π interactions (7). In none of these cases does the π-electron cloud of the cymantrenyl substituent take part in alkali metal ion complexation.