Schiff bases bearing an intramolecular hydrogen bond are known to undergo excited-state intramolecular proton transfer and E-Z isomerization, which are related to their thermochromism and solvatochromism properties. In this study, we explored these ultrafast photoinduced processes for two doubly hydroxylated Schiff bases, salicylidene-2-aminophenol and 2-hydroxynaphthylmethylidene-2-aminophenol...

In the title compound, [Na(4)(C(15)H(9)N(4)O(4))(4)(CH(3)OH)(4)], the N(3)O(3) environment around the Na(+) ion is distorted octa-hedral. In the unit cell, four Na(+) ions are bridged by four Schiff base anions, leading to a tetra-nuclear complex with -4 symmetry. O-H⋯N hydrogen bonds between the methanol mol-ecule and the Schiff base anion stabilize the structural set-up.

The mol-ecule of the title Schiff base compound, C(19)H(18)Cl(4)N(2), has crystallographic twofold rotation symmetry, with one C atom lying on the rotation axis. The dihedral angle between the two symmetry-related benzene rings is 84.70 (2)°. The plane of the -C=N-C- group is twisted away from the benzene ring by 7.5 (1)°. In the crystal structure, weak inter-molecular Cl⋯Cl [3.4851 (3) Å] cont...

In the title mononuclear copper(II) complex, [Cu(C(7)H(5)ClNO)(2)], the Cu atom, situated on an inversion center, is four-coordinated, in a slightly distorted square-planar geometry, by the N- and O-donor atoms of two symmetry-related 4-chloro-2-(imino-meth-yl)phenolate Schiff base ligands.

The crystal structure of the title Schiff base compound, C(16)H(16)N(2)O(3), is characterized by chains of mol-ecules linked by inter-molecular N-H⋯O hydrogen bonds running along the c axis. Further stabilization is provided by weak C-H⋯O contacts. The dihedral angle between the aromatic rings is 38.31 (7)°.

The mol-ecule of the title Schiff base compound, C(18)H(18)Br(2)N(2), lies across a crystallographic inversion centre and adopts an E configuration with respect to the C=N bond. In the crystal structure, mol-ecules are linked into chains along [201] through inter-molecular Br⋯Br inter-actions [3.3747 (3) Å], which are significantly shorter than the sum of the van der Waals radii for Br atoms (3...

New functionalized ethano-bridged Tröger bases are readily prepared using a simple alkylation/rearrangement sequence which affords configurationally stable derivatives as single stereoisomers (de > 96%).

The application of an external electric field to dry films of Asp-85-->Asn mutant bacteriorhodopsin causes deprotonation of the Schiff base, resulting in a shift of the optical absorption maximum from 600 nm to 400 nm. This is in marked contrast to the case of wild-type bacteriorhodopsin films, in which electric fields produce a red-shifted product whose optical properties are similar to those ...