Resorcinol, structure

Most of the metal chelates of 4-(2-pyridylazo)resorcinol (structure LXXXIX) are stable and form at low pH 62). The pH ranges of chelate... 

The resorcinol residue in (III) has predominantly catered for as a biologically effective replacement of the catechol moiety present in (IV). Importantly, the resorcinol structural analogue (III), in a striking contrast to the catechol (IV), is not a substrate for catechol-O-methyltransferase (COMT)-an extremely important metabolic enzyme and henee, it possesses a marked and pronounced longer duration of action. In fact, terbutaline serves as a useful selective (P2-adrenergic stimulant for the treatment of bronchial asthma and related physiologieal eonditions administered orally). 

Figure 2.6 The conventional way of presenting the resorcinol structure. Dotted lines represent hydrogen bonds, hydrogen atoms omitted. Compare to Figure 2.4.

Hydroquinone [123-31 -9] resorcinol [108-46-3] and catechol [120-80-9] (or pyrocatechol) are represented by structures (1), (2), and (3), respectively. This article reviews their syntheses and derivatives, production and use, and toxicology. 

Laminated beams (glulam), parallam (or LSL) and fingerjoints a flat pressed multilayer wood beam, thiek wood planks constituting the layers, used for structural exterior applications and bonded with PRF (phenol-resorcinol-formaldehyde) cold-setting resins, or MUF cold-setting resins, or even with certain types of polurethanes (although the use of these latter ones is only established in one country and can show creep and temperature-induced creep problems). The indi-... 

Resorcinol-formaldehyde (RF) and phenol-resorcinol-formaldehyde (PRF) coldsetting adhesives are used primarily in the manufacture of structural, exterior-... 

Developments in glued laminated structures and panel products such as plywood and chipboard raises the question of the durability of adhesives as well as wood. Urea-formaldehyde adhesives are most commonly used for indoor components. For exterior use, resorcinol adhesives are used for assembly work, whilst phenolic, tannin and melamine/urea adhesives are used for manufactured wood products. Urea and casein adhesives can give good outdoor service if protected with well-maintained surface finishes. Assembly failures of adhesives caused by exudates from some timber species can be avoided by freshly sanding the surfaces before glue application. 

Fig. 3.ia-c. Chemical structures of Jessner s Peel components (a Salicylic acid, b Resorcinol, and c Lactic acid)... 

It is a lipophilic compound which removes intercellular lipids that are covalently linked to the cornified envelope surrounding epithelial cells [3]. It also enhances penetration of other agents. Resorcinol (m-dihydroxy benzene) is structurally and chemically similar to phenol. It disrupts the weak hydrogen bonds of keratin [4]. Lactic acid is an alpha hydroxy acid which causes corneocyte detachment and subsequent desquamation of the stratum corneum [5]. 

Other chemicals such as hydroquinone and resorcinol, widely used in cosmetic dermatology, share a similar chemical structure with phenol (Fig. 8.1). 

As the majority of stabilisers has the structure of aromatics, which are UV-active and show a distinct UV spectrum, UV spectrophotometry is a very efficient analytical method for qualitative and quantitative analysis of stabilisers and similar substances in polymers. For UV absorbers, UV detection (before and after chromatographic separation) is an appropriate analytical tool. Haslam et al. [30] have used UV spectroscopy for the quantitative determination of UVAs (methyl salicylate, phenyl salicylate, DHB, stilbene and resorcinol monobenzoate) and plasticisers (DBP) in PMMA and methyl methacrylate-ethyl acrylate copolymers. From the intensity ratio... 

Tamon H, Ishizaka H, Mikami M, Okazaki M. Porous structure of organic and carbone aerogels synthesized by sol-gel polycondensation of resorcinol with formaldehyde. Carbon 1997 35 791-6... 

During the very first series of studies using single-crystal x-ray crystallography to determine the structures of organic molecules, Robertson reported the structure of resorcinol (1,3-dihydroxybenzene) [25]. This crystalline material corresponded to that ordinarily obtained at room temperature, and was later termed the a-form. Shortly thereafter, it was found that the a-form underwent a transformation into a denser crystalline modification (denoted as the P-form) when heated at about 74°C,... 

By its nature, resorcinol is locked into a single conformation, and it is immediately evident from a comparison of the structures in Fig. 7.9 that each form is characterized by a different motif of hydrogen bonding. In particular, the a-form features a relative open architecture that is maintained by a spiraling array of hydrogen bonding that ascends... 

Fig. 7.9. Crystal structures of the a- and P-forms of resorcinol, as viewed down the c-axis (001 plane). The figure is adapted from data given in Refs. [24] and [25],...

Chatteijee, A., Ebina, T., and Mizukami, F. 2005. Effects of water on the structure and bonding of resorcinol in the interlayer of montmorillonite nanocomposite—a periodic first principle study. J. Phys. Chem. B 109 7306-7313. 

An unusual scoop conformation of 24 has been characterised in the hydrate (C-methylcalix[4]resordnarene)(H20) [65]. The scoop conformation is a hybrid of the bowl and flattened cone conformations and there are two intramolecular O-H... 0 hydrogen bonds from adjacent resorcinol units. Adjacent 24 molecules form O-H... 0 hydrogen bonds and there are additional links via water molecules resulting a 2D sheet structure. The sheets pack in a bi-layer arrangement. 

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