Experimental and computational studies on pseudotetrahedral nickel(ii)-(S or R)-dihalogen-salicylaldiminates with Δ- or Λ-chirality induction at-metal

Abstract

Three pairs of pseudotetrahedral C2-symmetrical bis[(S or R)-N-1-(phenyl)ethyl-(2,4-X1,X2-salicylaldiminato-κ2N,O)]-Δ/Λ-nickel(II), Δ/Λ-NiSL1-3 or Λ/Δ-NiRL1-3 (X1, X2 = Cl, Cl; Br, Br; Cl, Br) with Δ- or Λ-chirality induction at-metal are synthesized, respectively. The...

Polymorphism, mesomorphism and anti-oxidant character of homoleptic bis[(E)-2-(1-((o-ethylphenyl)imino)ethyl)phenolato-κ2-N,O]Ni/Cu(ii) complexes

“…1, inset). 24,27,28,32,34,38 The absorption spectra were modelled using time-dependent density functional theory (TD-DFT) calculations using singlepoint calculations based on the DFT-optimized structures of 1 and 2 (Fig. 1 and Fig.…”

“…The Ni/Cu(II)-Schiff bases complexes in general can present both square-planar 28,32 and more pseudotetrahedral geometry. [24][25][26][27]29,38 Compounds 1 and 2a are isostructural, both solving in the triclinic space group P% 1. Compound 2b, in contrast, crystallises in the monoclinic space group P2 1 /n.…”

“…The results are consistent with irreversible electron transfer reactions, akin to what is generally seen for Cu/ Ni(II) complexes of similar Schiff base ligands. 24,27,32,37,43…”

“…Our recent research in this area has focused on the preparation and characterization of four-coordinate complexes of divalent transition metal ions with the Schiff base ligands (S or R)-N-1-(Ar)ethyl-salicylaldimine or -naphthaldimine (Ror S-HL 0 ; Ar = C 6 H 5 , p-CH 3 OC 6 H 4 ; p-Cl/BrC 6 H 4 ). [24][25][26][27][28][29][30] Molecular structures of such complexes with C 2 -symmetric, pseudotetrahedral geometry present induced D/L-chirality at-metal in the form of the diastereomers L-M(R-L 0 ) and D-M(R-L 0 ) (or D-M(S-L 0 ) and L-M(S-L 0 )). C 2 -symmetric pseudo-tetrahedral Co/Zn(II) complexes with the achiral Schiff bases (E)-2-(1-((Xphenyl)imino)methyl)naphthalen-2-ol (X = p-methyl, o-ethyl), for example, form D-M and L-M (M = Co, Zn) stereoisomers as a racemic mixture.…”