The BIAN ligand 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene: An electron sponge or a “normal” α-diimine ligand?

Re(i)-nitroxide complexes

“…Calculated parameters are in good agreement with typical g iso , A Re iso and A N i iso values of nitronyl/imino nitroxides 6,12 and reduced derivatives of rhenium(I) tricarbonyl diimine complexes fac-[(a-diimine À c)Re I (CO) 3 (L)]. [20][21][22][23] The high natural isotropic hyperne splitting constant of Re nuclei 24 makes it possible to clearly observe their coupling with the unpaired electron of nitroxide fragments. According to the results of molecular DFT calculations (ORCA 4.2 quantum chemistry package 25 with range-separated LC-BLYP functional and def2-TZVPP basis set), the spin density is found to be mainly localized on {O)N]C-N-cO}/{N]C-N-cO} fragments and has a very small value at the rhenium(I) center (Fig.…”

Oxidation State Assignments in the Organoplatinum One‐Electron Redox Series [(N^N)PtMes2]n, n = +,0, –,2‐

“…addition reactions . Figure , Figure , and Figure and S1–S2 also illustrate the role of N,N' substituents in the BIAN containing complexes, further shielding the metal from outside attack …”

“…below) the 1 H‐ and 195 Pt‐NMR spectra, CHN analysis and mass spectrometry confirmed the identity of the complexes. The use of N,N'‐bis(triisopropyl)‐1,2‐bis‐iminoacenaphthene ( i Pr‐BIAN) did not result in coordination of PtMes 2 , and neither did experiments with the bulkier triisopropylphenyl (Tipp) instead of mesityl ligands at platinum produce corresponding compounds.…”

“…The compounds 2–4 with the more sophisticated electronic structure of the ligands, i.e. having two close lying π* orbitals of α‐diimine and naphthalene character, 5b 2 and 4a 2 (Figure S6),, exhibit three bands between 430 and 800 nm. The corresponding transitions involving several high lying occupied MOs and variable unoccupied MOs will be subject of a further extended study.…”

“…As alternative N ^ N ligands to the conventional 2,2'‐bipyridine,[16a] 1,10‐phenanthroline,[16b] and other diimines[16c] we now employed three differently substituted R‐BIAN ligands with their special steric and electronic properties and the six‐membered chelate ring forming bik = bis(1‐methyl‐2‐imidazolyl)ketone ligand (Figure )…”