DNA carries genetic information in its sequence of bases. Synthetic oligonucleotides that can sequence-specifically recognize a target gene sequence are a useful tool for regulating gene expression or detecting target genes. Among the many synthetic oligonucleotides, tail-clamp peptide nucleic acid (TC-PNA) offers advantages since it has two homopyrimidine PNA strands connected via a flexible e...

In this study, a series of isatin-based Mannich bases were prepared and their biological activity was evaluated. Schiff bases of isatin were synthesized by condensation of the keto group of isatin with different aromatic primary amines. The NMannich bases of the above Schiff bases were synthesized by reaction of the acidic imino group of isatin with formaldehyde and secondary amine. The chemica...

New crown ether Schiff base derivatives were prepared by the condensation of 4'-formylbenzo-15-crown-5 or 4'-formyl-5'-hydroxybenzo-15-crown-5 with 1,2-bis(2-aminophenoxy)ethane. The structures of these new compounds were confirmed on the basis of elemental analysis, IR, (1)H- and (13)C-NMR, UV-Vis and mass spectroscopic data.

The title Schiff base compound, C(17)H(13)N(3)O(3), crystallizes in a zwitterionic form and exists in a trans configuration about the C=N bond. The mol-ecule is slightly twisted, the dihedral angle between the benzene ring and naphthalene ring system being 10.80 (9)°. The nitro group is twisted relative to the plane of the benzene ring [dihedral angle = 8.88 (12)°]. Bifurcated intra-molecular N...

In the title centrosymmetric mononuclear nickel(II) complex, [Ni(C(13)H(20)N(2)O(2))(2)](ClO(4))(2), the Ni(II) atom is four-coordinated by the imine N and phenolate O atoms of the zwitterionic forms of two Schiff base ligands in a square-planar coordination geometry. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains running along the a...

In the title compound, [ZnI(2)(C(13)H(19)N(3)O)], the Zn(II) ion is five-coordinated in a distorted square-pyramidal geometry, in which the basal plane is defined by three N atoms from the Schiff base ligand and one iodide ion. A second iodide ligand, situated in the apical position, completes the coordination geometry. In the crystal structure, C-H⋯O hydrogen bonds link a pair of mol-ecules ar...

The title compound, C(12)H(14)N(5)O(2) (+)·Br(-), is the hydro-bromide salt of a Schiff base in which protonation has taken place at the pyridine N atom. This organic cation is essentially planar (r.m.s. of all fitted non-H atoms = 0.0448 Å). In the crystal, N-H⋯Br hydrogen bonds as well as C-H⋯O and C-H⋯Br inter-actions connect the mol-ecules, forming a three-dimensional network.

The title Schiff base compound, C(14)H(9)Cl(3)N(2)O, exists in a trans configuration with respect to the C=N bond and the dihedral angle between the two benzene rings is 13.5 (2)°. In the crystal, inter-molecular N-H⋯O hydrogen bonds link adjacent mol-ecules into extended C(4) chains propagating along the c-axis direction.

In the title mononuclear cobalt(III) compound, [Co(C(9)H(8)ClNO(2))(C(9)H(9)ClNO(2))], the Co(II) atom is six-coordinated by two imine N atoms, two phenolate O atoms, and one hy-droxy and one oxide O atom from two Schiff base ligands, forming an octa-hedral geometry. In the crystal structure, adjacent mol-ecules are linked through inter-molecular O-H⋯O hydrogen bonds. The 2-oxidoethyl group is ...