Tuning the LUMO energy of 1,10-phenanthroline in α-diimine-dithiolate Ni(II) complex and enhancement of nonlinear optical properties

摘要: Abstract The synthesis, characterization, nonlinear optical properties and DFT calculations for a new Ni-diiminedithiolate complex [Ni(Cl4-phen)(mi-5edt)] (Cl4-phen = 3,4,7,8-tetrachloro-1,10-phenanthroline; mi-5edt = 1-(N-methylindol-5-yl)-ethene-1,2-dithiolate), are reported. UV–Vis spectrum shows solvatochromic absorption at 700 nm in DMF (e = 5520 mol−1 dm3 cm−1) due to charge-transfer (CT) highest occupied molecular orbital (HOMO)–lowest unoccupied (LUMO) transition, typical of push–pull complexes. CT character this electronic transition is confirmed by with the HOMO mainly centered on mi-5edt moiety LUMO Cl4-phen ligand. By comparison unsubstituted analogue compound, computational studies confirm role chlorination enhancing complex. second order were measured EFISH technique (at 1.907 μm), giving values −2030 −810 × 10−48 esu μβ1.907 μβ0, respectively. These among reported so far class d8 square-planar compounds.