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4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H 2 NC 6 H 4 OH. Typically available as a white powder, [ 3 ] it is commonly used as a developer for black-and-white film , marketed under the name Rodinal .
The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
The classical methods for the production of paracetamol involve the acetylation of 4-aminophenol with acetic anhydride as the last step. They differ in how 4-aminophenol is prepared. In one method, nitration of phenol with nitric acid affords 4-nitrophenol, which is reduced to 4-aminophenol by hydrogenation over Raney nickel.
The bulk compounds should be contrasted with nanoparticles which exhibit melting-point depression, meaning that they have significantly lower melting points than the bulk material, and correspondingly lower Tammann and Hüttig temperatures. [4] For instance, 2 nm gold nanoparticles melt at only about 327 °C, in contrast to 1065 °C for a bulk ...
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry , alcohols and carboxylic acids contain one or more hydroxy groups.
The carbon–oxygen bond length in these cations is near 1.1 Å (110-112 pm), which is shorter than the 112.8 pm of carbon monoxide and indicates triple-bond character. [ 5 ] [ 6 ] [ 7 ] The carbon centres of acylium ions generally have a linear geometry and sp atomic hybridization , and are best represented by a resonance structure bearing a ...
Morpholine undergoes most chemical reactions typical for other secondary amines, though the presence of the ether oxygen withdraws electron density from the nitrogen, rendering it less nucleophilic (and less basic) than structurally similar secondary amines such as piperidine. For this reason, it forms a stable chloramine. [10]