Hydroxyl group terms Links

The first research on these compounds was carried out by Claus,2 who described two classes of ammino-derivatives obtained from ruthenium diehloride, namely, those obtained from tlie hydroxide, Ru(NH3)4(OH)2, and those from the hydroxide of composition Ru(NH3)2(OH)2. These compounds were examined later by Jolv,3 who showed that they contained, besides ammonia and hydroxyl group, a nitroso-group linked to ruthenium, giving rise to the trivalent group (RuNO). He termed them ruthenium nitroso-ammonium compounds. These containing two molecules of ammonia were represented by the formula Ru(NH3)2NO(OH)3.H20, and those containing four molecules of ammonia in the molecule by the formula Ru(NH3)4NO.OH.R2 (where R represents a monovalent acidic radicle). 

The first synthetic plastics were the phenol-formaldehyde resins introduced by Baekeland in 1907 [1], Melamine and urea also react with formaldehyde to form intermediate methylol compounds which condense to cross-linked polymers much like phenol-formaldehyde resins. Paper, cotton fabric, wood flour or other forms of cellulose have long been used to reinforce these methylol-functional polymers. Methylol groups react with hydroxyl groups of cellulose to form stable ether linkages to bond filler to polymers. Cellulose is so compatible with these resins that no one thought of an interface between them, and the term reinforced composites was not even used to describe these reinforced systems. 

Supports used for obtaining Ziegler-Natta catalysts can differ essentially from one another. Some of the supports may contain reactive surface groups (such as hydroxyl groups present in specially prepared metal oxides) while others do not contain such reactive functional groups (such as pure anhydrous metal chlorides). Therefore, the term supported catalyst is used in a very wide sense. Supported catalysts comprise not only systems in which the transition metal compound is linked to the support by means of a chemical covalent bond but also systems in which the transition metal atom may occupy a position in a lattice structure, or where complexation, absorption or even occlusion may take place [28]. The transition metal may also be anchored to the support via a Lewis base in such a case the metal complexes the base, which is coordinatively fixed on the support surface [53,54]. 

As more than one hydroxyl group linked to a single carbon atom results in an unstable compound, the simplest di-hydroxy alcohol is the one derived from the two carbon hydrocarbon ethane (i.e.) dihydroxy ethane, or glycol, CH2—(OH) — CH2(OH). Similarly the simplest tri-hydroxy alcohol is derived from the three carbon hydrocarbon propane. It is known commonly as glycerin, but is better termed glycerol, as the termination, ol, signifies an alcohol. 

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