4′-Fluoro-2′-hydroxy­acetophenone

The title compound, C8H7FO2, crystallizes as discrete mol­ecules, the conformation of which may be influenced by an intra­molecular hydr­oxy–carbonyl O—H⋯O hydrogen bond

3,5-Dichloro­salicylaldehyde

The title compound (systematic name: 3,5-dichloro-2-hydroxy­benzaldehyde), C7H4Cl2O2, crystallizes as discrete mol­ecules, the conformation of which may be influenced by an intra­molecular hydr­oxy–carbonyl O—H⋯O hydrogen bond

Electron-topological, energetic and π-electron delocalization analysis of ketoenamine-enolimine tautomeric equilibrium

The ketoenamine-enolimine tautometic equilibrium has been studied by the analysis of aromaticity and electron-topological parameters. The influence of substituents on the energy of the transition state and of the tautomeric forms has been investigated for different positions of chelate chain. The quantum theory of atoms in molecules method (QTAIM) has been applied to study changes in the electron-topological parameters of the molecule with respect to the tautomeric equilibrium in intramolecular hydrogen bond. Dependencies of the HOMA aromaticity index and electron density at the critical points defining aromaticity and electronic state of the chelate chain on the transition state (TS), OH and HN tautomeric forms have been obtained

CO₂ laser dye patterning for textile design and apparel manufacture

Digital dyeing technique, described as ‘Digital Laser Dyeing’ (DLD) was studied in this research using CO2 laser technology, synthetic textiles, workshop coloration methods and industry standard dyes and dyeing procedures. Laser beam energy was used as an image creation tool to modify surface fibres with graphic patterns and coloured dyed effects through a Computer Aided Design (CAD) approach. The research was supported by a textile design perspective in order to explore the creative potential of DLD methods for textile processing, fabric finishing, fashion design and apparel manufacture. Combined technical and scientific inquiry ensured experimental rigor in terms of the repeatable methods employed and reliable results achieved using an energy density (J/cm2) approach. Outcomes of the study identified CO2 laser-dye patterning as an innovative alternative textile coloration approach and dye on demand manufacturing process relevant to textile and clothing production. Explorations with polyester/elastane sportswear and intimate garments in this study suggest a potential sector for the development of on demand processing for synthetic textiles and clothing

Hydrogen bonding interactions of benzylidene type Schiff bases studied by vibrational spectroscopic and computational methods

The structural features of four benzylidene type Schiff bases [(E)-benzaldehyde-N-phenyl imine, (A) (E)-2-hydroxybenzaldehyde-N-phenyl imine (B) (E)-benzaldehyde-N-2-hydroxyphenyl imine (C) (E)-2-hydroxybenzaldehyde-N-2-hydroxyphenyl imine (D)] were studied by FT-IR spectroscopy in solution, photoacoustic and Raman spectroscopies in the solid state and quantum chemical calculations. It was found that molecule D dimerised in the solid state with concomitant loss of aromaticity in the benzylidene ring. Beside the intermolecular C=O...HO hydrogen bonds, intramolecular N-H...C=O hydrogen bonds could be found experimentally as well as computationally. Spectra taken in solution and ab initio quantum chemical calculation helped to identify hydrogen bonding interactions occurring for compounds B and C. Intramolecular OH...N hydrogen bond predominated in molecule B, while this interaction, although it existed, was weaker

Digital laser-dyeing for polyester fabrics

Surface polyester fibers modified by laser beam energy have been found to display improved dye uptake (Lau et al. 1997; Kamel et al. 2012; Shahidi et al. 2013). This research considers “laser-dye” patterning as an alternative coloration method within a textile design context. In this study, standardized polyester (PET) knitted jersey and plain, woven fabrics were modified with CO2 laser technology to engineer dye onto the fabric with high-resolution graphics. The work considered the aesthetic possibilities, production opportunities, and environmental potential of the process compared to traditional and existing surface design techniques. Laser-dyed patterns were generated by a digital dyeing technique involving CAD, laser technology, and dye practices to facilitate textile coloration and patterning. An understanding of energy density was used to define the tone of a dye in terms of color depth in relation to the cloth. In so doing, a system for calibrating levels of color against laser energy in order to build a tonal image was found. Central to the investigation was the consideration of the laser beam spot as a dots-per-inch tool, drawing on the principles used in digital printing processes. It was therefore possible to utilize the beam as an image-making instrument for modifying textile fibers with controlled laser energy. Quantitative analysis of the outcomes alongside creative exploration facilitated both a tacit understanding of, and ability to control, processing parameters. This enabled repeatability of results parallel to design development and has established the potential to apply the technique commercially. Sportswear prototypes produced in the study suggest a suitable market for processing polyester garments in this way

Di-n-butyl 4,4′-dihy­droxy-3,3′-{[(3aRS,7aRS)-2,3,3a,4,5,6,7,7a-octa­hydro-1H-1,3-benzimidazole-1,3-di­yl]bis­(methyl­ene)}dibenzoate

The complete molecule of the title compound, C31H42N2O6, is generated by crystallographic twofold symmetry, with one C atom lying on the axis. The dihedral angle between the aromatic rings is 57.03 (6)°. The central heterocyclic ring adopts a half-chair conformation. The mol­ecular conformation is stabilized by two intra­molecular O—H⋯N hydrogen bonds with the N atoms of the heterocyclic ring as the acceptors. In the crystal, mol­ecules are linked into chains along the c axis by non-classical C—H⋯O hydrogen bonds

2,2′-[Imidazolidine-1,3-diylbis(methyl­ene)]diphenol

In the title mol­ecule, C17H20N2O2, the imidazolidine ring adopts a twist conformation. The mean plane through the five atoms of the imidazolidine ring makes dihedral angles of 70.18 (4) and 74.14 (4)° with the planes of the two aromatic rings. The dihedral angle between the benzene rings is 53.11 (5)°. Both phenol –OH groups form intra­molecular hydrogen bonds to the N atoms, with graph-set motif S(6). In the crystal, pairs of O—H⋯O hydrogen bonds link the mol­ecules into dimers with R 4 4(18) ring motifs. The crystal packing is further stabilized by C—H⋯O and weak C—H⋯π inter­actions

2-[(4-Chloro­phen­yl)imino­meth­yl]hydro­quinone

The title compound, C13H10ClNO2, exists in the phenol–imine form in the crystal, and the aromatic rings are oriented at a dihedral angle of 2.82 (9)°. An intra­molecular O—H⋯N hydrogen bond results in the formation of a planar six-membered ring. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into chains