New Schiff bases have been prepared by reacting 3-hydroxy-4-pyridine- carboxaldehyde with various amines. NMR spectroscopic methods provided clear evidence that the Schiff bases exist in the solid state and in solution as hydroxyimino tautomers with the E-configuration. A study of the stabilities of the tautomeric forms and the different conformers has been carried out using density functional ...

In the title compound, [Zn(C(12)H(11)N(2)O)(2)], the Zn(II) atom, lying on an inversion center, is coordinated by two O atoms and two N atoms from two salicylal Schiff base ligands in a distorted square-planar geometry. A three-dimensional network is formed by inter-molecular C-H⋯N hydrogen bonds and C-H⋯π contacts.

The title Schiff base, C(14)H(14)N(2)O(2), is close to being planar (r.m.s. deviation for the non-hydrogen atoms = 0.052 Å) and an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, the moleucles are linked by O-H⋯O hydrogen bonds, giving rise to helical chains propagating along the c axis of the tetra-gonal unit cell.

The Zn(II) atom in the title compound, [Zn(C(14)H(11)N(3)O(2)S)(C(12)H(8)N(2))]·0.5C(10)H(8)N(2), is N,N'-chelated by the N-heterocycle and N,O,S-chelated by the deprotonated Schiff base in a square-pyramidal environment. The hydr-oxy group of the Schiff base is a hydrogen-bond donor to 4,4'-bipyridine, which is located about a center of inversion, resulting in the formation of a supra-molecula...

We consider the problem of implementing mutually unbiased bases (MUB) for a polarization qubit with only one wave plate, the minimum number of wave plates. We show that one wave plate is sufficient to realize two MUB as long as its phase shift (modulo 360°) ranges between 45° and 315°. It can realize three MUB (a complete set of MUB for a qubit) if the phase shift of the wave plate is within [1...

In the monomeric dinuclear title complex, [CuSm(C(20)H(22)N(2)O(4))(NO(3))(3)], the four-coordinate Cu(II) ion has a square-planar geometry involving two O atoms and two N atoms of the deprotonated Schiff base ligand. The Sm(III) ion is ten-coordinate, chelated by four O donor atoms of the Schiff base and two O atoms each from three bidentate nitrate groups, one of which is disordered over two ...

In the title compound, [Sn(C(6)H(11))(2)(C(19)H(14)N(2)O(3))], the Sn(IV) atom is O,N,O' chelated by the deprotonated Schiff base ligand and exists in a cis-trigonal-bipyramidal environment, completed by the two cyclohexyl ligands.

The asymmetric unit of the title compound, [Ni(C(17)H(12)I(4)N(2)O(2))], comprises half of a Schiff base complex. The Ni(II) and central C atom of the propyl chain are located on a twofold rotation axis. The geometry around the Ni(II) atom is square planar, supported by the N(2)O(2) donor atoms of the coordinated ligand. In the crystal, there are no significant inter-molecular inter-actions pre...

In the title Schiff base, C(22)H(20)N(2)O(2), the benzene ring forms dihedral angles of 53.92 (1) and 3.62 (1)° with the two salicylaldimine groups. There are two strong O-H⋯N intra-molecular hydrogen bonds. The crystal packing is stabilized by weak inter-molecular C-H⋯O hydrogen bonds and π-π stacking inter-actions (average distance 3.39 Å).