Hemilabile and luminescent palladium(II) azo-2-phenylindole complexes

摘要: Abstract The synthesis of three azoderivatives {R1–N N–R2 with R1 = 2-phenylindole and R2 = 4-Me–C6H4– (2a), 4-Cl–C6H4– (2b) or 2-phenylindole (2c)} the study their reactivity in front Pd(II) salts are described. Treatment 2a 2b PdCl2 a CH2Cl2:CH3OH mixture at 298 K followed by action PPh3 produced cyclopalladated complexes: [Pd(κ2-C,N)Cl(PPh3)] (3a 3b) σ{Pd–C(indole)} bond. For 2c, metallation takes place on same position but required stronger reaction conditions {Pd(OAc)2 acetic acid 398 K}. A comparative spectroscopic photo-optical properties ligands 2a–2c palladium(II) derivatives (3a–3c) is also reported. Addition to CH2Cl2 solutions compounds 3a–3c opening six-membered metallacycle formation trans-[Pd(κ1-N)Cl(PPh3)2] (4a–4c). crystal structures 3c·CH2Cl2, 4a, 4b 4c·3/2CH2Cl2·1/2H2O confirm mode binding anti-(E) configuration complexes as well relative disposition remaining bound atom. Solution studies reveal that CDCl3, Pd–N bond 4a–4c hemilabile. Computational (at DFT PM6 level) have been performed order rationalize high degree regioselectivity cyclopalladation process solution behaviour 4a–4c.