New chiral Schiff base–Cu(II) complexes as cyclopropanation catalysts

Copper(II) complexes of coumarin-derived Schiff bases and their anti-Candida activity

“…Coordination of the Cu(II) centre to both ligands is via the imine nitrogen and phenolic oxygen atoms. Bond lengths between the Cu(II) centre and the donor atoms are consistent with previously reported compounds of similar structures [54,67]. There is no centre of symmetry in the molecule which is reflected particularly in the bond length differences between copper and each of the nitrogen atoms of the two ligands coordinated to it; 1.973 (5) (Fig.…”

“…Upon complexation, the phenolic m C-O stretching vibration shifted to lower frequency, suggesting coordination of this oxygen atom. Several new bands present in the region 400-600 cm À1 in the spectra of the complexes were assigned to m Cu-N and m Cu-O stretching vibrations [52][53][54][55].…”

“…In the IR spectra of almost all the complexes the m CN stretching vibration associated with the imine functional group of the ligand was shifted to a lower wavelength compared to that in the corresponding free ligand, indicating that coordination to the Cu(II) ion occurs via the imine nitrogen (Table 7) [54,55]. The m C@O stretching vibration of the carbonyl function in the lactone ring of the free ligands appeared as a strong sharp band in the range 1688-1733 cm À1 .…”

Anticancer and antifungal activity of copper(II) complexes of quinolin-2(1H)-one-derived Schiff bases

“…Two MeOH molecules and one DMSO molecule are also present within the asymmetric unit. The ligand coordinated to the copper(II) ion via the phenolic oxygen (at C15) and the nitrogen of the imine bond as expected [59,60]. The copper atom was surrounded by a N 2 O 2 donor set formed by the phenolic oxygens: Cu1-O20 = 1.915(3) and Cu1-O1 = 1.916(3) Å and the nitrogen of azomethines from two ligand molecules: Cu1-N28 = 1.964(3), Cu1-N9 = 1.975(3) Å.…”

Bidentate Schiff bases derived from (S)-α-methylbenzylamine as chiral ligands in the electronically controlled asymmetric addition of diethylzinc to aldehydes

“…6,7,16 and 17. The detailed analysis revealed that our compounds have already been synthesized as the same enantiomers (2, 4, 8) 6,7 , or as Renantiomers (1, 9) 16,17 while all our compounds have S-configuration. Comparison of our results The solution spectra indicated that the electronic properties of SB 1-9 were strongly dominated by the donor-acceptor chromophore (Fig.…”