Molecular structures of dinuclear zinc(II) complexes of chiral tridentate imine and amine ligands: Effect of ligand geometry on diastereoselectivity
摘要:
Racemic mixtures of Schiff bases (L1H and L2H) were reduced to respective amines (L1'H and L2'H). Compounds of composition [Zn-2(L1)(2)(NCO)(2)] (1), [Zn(L1)N-3](n) (2), [Zn-2(L-2)(2)(NCO)(2)] (3), [Zn-2(L1')(2)(NCO)(2)] (1'), [Zn-2(L1)(2)(N-3)(2)]center dot 2DMF (2'center dot 2DMF) and [Zn-2(L2')(2)(NCO)(2)]center dot DMF (3'center dot DMF) were synthesized using these ligands, Zn(NO3)(2)center dot 6H(2)O and NCO or N-3 ions. Molecular structures of all six compounds have been established. Both imine and amine ligands have N2O donor set, but coordinate, respectively, in meridional and facial fashions. First four complexes are monochelates and last two are bis-chelates. The Zn2O2 unit in 1-3 has RS combination of imine where as in 1' has RR(SS) combinations of amine. In 2' and 3', zinc(II) bis-chelates have cis, cis, trans-(O-P)(2)(N-A)(2)(N-Y)(2) stereochemistry and cis-(O-P)(2) disposition further coordinate to tetrahedral zinc. Compound 1' exhibits 1D hydrogen-bonded polymer by enantioselective H-bonding interaction. In 2', DMF molecules assemble RR and SS bis-chelates through N-H center dot center dot center dot O interactions. (C) 2012 Elsevier B. V. All rights reserved.
Molecular structures of dinuclear zinc(II) complexes of chiral tridentate imine and amine ligands: Effect of ligand geometry on diastereoselectivity
摘要:
Racemic mixtures of Schiff bases (L1H and L2H) were reduced to respective amines (L1'H and L2'H). Compounds of composition [Zn-2(L1)(2)(NCO)(2)] (1), [Zn(L1)N-3](n) (2), [Zn-2(L-2)(2)(NCO)(2)] (3), [Zn-2(L1')(2)(NCO)(2)] (1'), [Zn-2(L1)(2)(N-3)(2)]center dot 2DMF (2'center dot 2DMF) and [Zn-2(L2')(2)(NCO)(2)]center dot DMF (3'center dot DMF) were synthesized using these ligands, Zn(NO3)(2)center dot 6H(2)O and NCO or N-3 ions. Molecular structures of all six compounds have been established. Both imine and amine ligands have N2O donor set, but coordinate, respectively, in meridional and facial fashions. First four complexes are monochelates and last two are bis-chelates. The Zn2O2 unit in 1-3 has RS combination of imine where as in 1' has RR(SS) combinations of amine. In 2' and 3', zinc(II) bis-chelates have cis, cis, trans-(O-P)(2)(N-A)(2)(N-Y)(2) stereochemistry and cis-(O-P)(2) disposition further coordinate to tetrahedral zinc. Compound 1' exhibits 1D hydrogen-bonded polymer by enantioselective H-bonding interaction. In 2', DMF molecules assemble RR and SS bis-chelates through N-H center dot center dot center dot O interactions. (C) 2012 Elsevier B. V. All rights reserved.
Molecular structures of dinuclear zinc(II) complexes of chiral tridentate imine and amine ligands: Effect of ligand geometry on diastereoselectivity
作者:Himanshu Sekhar Jena、Vadivelu Manivannan
DOI:10.1016/j.ica.2012.06.041
日期:2013.1
Racemic mixtures of Schiff bases (L1H and L2H) were reduced to respective amines (L1'H and L2'H). Compounds of composition [Zn-2(L1)(2)(NCO)(2)] (1), [Zn(L1)N-3](n) (2), [Zn-2(L-2)(2)(NCO)(2)] (3), [Zn-2(L1')(2)(NCO)(2)] (1'), [Zn-2(L1)(2)(N-3)(2)]center dot 2DMF (2'center dot 2DMF) and [Zn-2(L2')(2)(NCO)(2)]center dot DMF (3'center dot DMF) were synthesized using these ligands, Zn(NO3)(2)center dot 6H(2)O and NCO or N-3 ions. Molecular structures of all six compounds have been established. Both imine and amine ligands have N2O donor set, but coordinate, respectively, in meridional and facial fashions. First four complexes are monochelates and last two are bis-chelates. The Zn2O2 unit in 1-3 has RS combination of imine where as in 1' has RR(SS) combinations of amine. In 2' and 3', zinc(II) bis-chelates have cis, cis, trans-(O-P)(2)(N-A)(2)(N-Y)(2) stereochemistry and cis-(O-P)(2) disposition further coordinate to tetrahedral zinc. Compound 1' exhibits 1D hydrogen-bonded polymer by enantioselective H-bonding interaction. In 2', DMF molecules assemble RR and SS bis-chelates through N-H center dot center dot center dot O interactions. (C) 2012 Elsevier B. V. All rights reserved.