Near-IR absorbing donor–acceptor ligand-to-ligand charge-transfer complexes of nickel(ii)

Abstract

Ligand-to-ligand charge-transfer complexes of nickel(ii) incorporating azanidophenolate donor ligands absorb near-IR light to access highly reducing excited states.

Impact of Group 10 Metals on the Solvent‐Induced Disproportionation of o‐Semiquinonato Complexes

“…[14] The reactiono f3 ,5-DTBCatH 2 with the yellow dichloride complexes[ M II Cl 2 (DTBbpy)] (M = Ni and Pd) under basic conditions afforded dark-purple solids of [M II (3, [17] [Pd],a nd [Pt] in the solid state wereu nequivocally determined by singlecrystal X-ray diffraction analysis (Figure 1), and selected bond lengths are presented in Table 1. [14] The reactiono f3 ,5-DTBCatH 2 with the yellow dichloride complexes[ M II Cl 2 (DTBbpy)] (M = Ni and Pd) under basic conditions afforded dark-purple solids of [M II (3, [17] [Pd],a nd [Pt] in the solid state wereu nequivocally determined by singlecrystal X-ray diffraction analysis (Figure 1), and selected bond lengths are presented in Table 1.…”

“…[23] It is noteworthy that the LL'CT bands of [Pd] in polar solvents (MeOH, EtOH,D MF,a nd DMSO) appear at shorterw avelengths than those of [Pt].T he transition energies of the LL'CT bands of [Pd] show al inear correlation with the Pt(NN)(SS) solventp arameters, [24] similarly to the case of [Pt].T he slope of the fitted curve for [Pd] (4343 cm À1 ) is slightly highert han that estimated for [Pt] (4198 cm À1 ;F igure 3a). [17]. These features reveal am ore pronounced neg- (2) 1.351 (3)1.349 (4) [a] See Ref.…”

“…This solution was concentrated to approximately 10 mL and n-hexane (30 mL) was then added to afford a dark-green precipitate, which was collected by filtration, washed sequentially with n-hexane and water,a nd dried in vacuo. [38] Selected crystallographic data for [Ni], [17] [Pd], and [Pt] are presented in Ta ble 5. Elemental analysis calcd (%) for C 32 Crystallographic data collection and structure refinement:C rystallographic measurements were carried out on aR igaku VariMax Saturn CCDC diffractometerb yu sing graphite-monochromated Mo Ka radiation (l = 0.71075 ).…”

“…This spectrum could be reproduced by as uperposition of the resonances of free 3,5-DTBBQ 0 and [Pd II Cl 2 (DTBbpy)] (Figure 5e and Figure To gain furtheri nsight into the observed trends regarding the solvent-, metal-ion-, and temperature-dependent disproportionation behavior of {[M](PF 6 )} n (M = Ni (n = 2), Pd (n = 1), andP t (n = 1)), we conducted electrochemical studies as the redox potential serves as an indicator of the stability of each species. [17] On the other hand, [Pd] and [Pt] exhibit quasi-reversible one-electron reductions at À1.73 and À1.70 V, respectively. [17] On the other hand, [Pd] and [Pt] exhibit quasi-reversible one-electron reductions at À1.73 and À1.70 V, respectively.…”

“…[28] Figure 7s (Figure 7a), which indicates the instability of the bpyC À species boundt o the Ni II center. [17] Upon scanning the potentiali nt he positive direction, [Ni] undergoes ao ne-electron oxidation with poor reversibility at À0.06 V ( Figure 7a). [17] Upon scanning the potentiali nt he positive direction, [Ni] undergoes ao ne-electron oxidation with poor reversibility at À0.06 V ( Figure 7a).…”