EPR study of mono-o-iminobenzosemiquinonato nickel(II) complexes with Ni–C σ-bond

Transition metal complexes with bulky 4,6-di-tert-butyl-N-aryl(alkyl)-o-iminobenzoquinonato ligands: Structure, EPR and magnetism

“…Ruthenium complex 13 has a value of g = 2.0049 at 298 K with hyperfine coupling of the unpaired electron with both the nitrogen atom of o-iminobenzosemiquinone ligand and the ruthenium ( Table S2). The value A( 14 N) = 7.8 G is typical for ISQ complexes [34,35,39] but A( 99 Ru) = 10.1 G, A( 101 Ru) = 11.3 G are greater than those observed for other Ru-complexes (4-8 G for A( 99 Ru) and 4.4-8.6 G for ( 101 Ru)). This was rationalized in terms of a large ligand-to-metal spin transfer [11].…”

“…Eq. (3) in Scheme 3 exhibits the synthesis of mono-o-iminobenzosemiquinonato nickel complexes of (Ph 3 P)Ni(ISQ)(o-Tol) type (ISQ is ISQ L2 , 15; ISQ L3 , 16; ISQ L7 , 17) with Ni-C -bond [39]. (iii) One can use exchange reactions of the neutral ligand (e.g.…”

“…exchange of PPh 3 with AsEt 3 , Py, Pyz, Et 3 N, isonitriles RNC, Me 3 P etc.). They do not affect the oiminobenzosemiquinonato ligand in coordination sphere [39] (Eq. (3) in Scheme 3).…”

New tin(IV) complexes with sterically hindered o‐iminobenzoquinone ligand: Synthesis and structure

“…The crystal data collection and structure refinement data are listed in Table 2. Crystals suitable for X-ray analysis were obtained from pentane (2) and diethyl ether (3).…”

“…This type of ligands can coordinate to a metal ion in unreduced [2], oneelectron reduced o-iminobenzosemiquinone radical (iSQ), and two-electron reduced o-amidophenolate (AP) forms. The use of o-iminosemiquinone as a spin label in metal complexes allows us to monitor complex composition, structure, and dynamic processes in coordination sphere by simple means of EPR spectroscopy [3]. On the other hand, o-iminosemiquinones can be considered as the magnetic centers.…”