Hydroxy nests

Namely, aluminium atoms can be inserted into the hydroxyl nests composed of four SiOH groups, and also into the lattice imperfections formed from the hydroxy nests by the dehydration. The above results and discussion have been described in detail elsewhere [11]. 

Fig. 10.15. Hydroxy nest produced on removal of aluminum from a zeolite.

Phosgene proved to be an appropriate reactant to remove aluminium from the zeolite framework [1,2]. Detailed measurements have been carried out to investigate the adsorption of phosgene [3], the mechanism of dealumination by infrared spectroscopic and thermogravimetric methods [4], structural consequences [5], adsorption and catalytic properties of modified mordenites [6]. In addition an NMR study has been carried out, to measure the thermal stability of so-called hydroxy nests in H-mordenite dealuminated with phosgene [7]. 

The best understood of the sexual pheromones of social insects is the queen substance of honeybees. Interestingly, the queen substance used for queen control inside the nest is also the substance used by virgin queens to attract drones for mating. Callow and Johnston (1960) and Barbier and Lederer (1960) identified 9-keto-2(E)-decenoic acid ([E]-9-oxodec-2-enoic acid) (9-ODA) as major components of the queen mandibular glands. 9-Hydroxy-2(E)-decenoic acid is also present (Callow et al., 1964) and together both attract drones. Additional components of the queen retinue pheromone have recently been identified (Keeling et al., 2003). 

The rare bird s nest fungus Cyathus intermedius produces the yellow xanthone pigment (391) in small amounts when grown in laboratory fermentations 56). The structure (391) was confirmed by synthesis involving regioselective hydroxylation of l-hydroxy-6,8-dimethylxan-thone (Scheme 65). It seems likely that the xanthone (391) arises in the fungus from an octaketide derived anthraquinone precursor. 

Ayer, W.A., and D.R. Taylor Metabolites of Bird s Nest Fungi 5. The Isolation of l-Hydroxy-6-methyl-8-hydroxymethylxanthone, a New Xanthone, from Cyathus intermedins. Synthesis via Photoenolisation. Canad. J. Chem. 54, 1703 (1976). 

The commercial polymers used in the study are characterized in Table 1. The polypropylenes PP1-PP5 were homopolymers exhibiting different melt viscosities (see Fig. 1) supplied by Neste Chemicals. Liquid-crystalline polymer 1 (LCPl) (Vectra A950 by Hoechst Celanese) is a totally aromatic polyester-type thermotropic main-chain LCP copolymer based on p-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA). Liquid-crystalline polymer 2 (LCP2) (Rodrun LC-3000 by Unitika Ltd) is a more flexible thermotropic main-chain LCP copolyester consisting of 60%... 

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