Search results
Results from the WOW.Com Content Network
Zinc pyrithione (or pyrithione zinc) is a coordination complex of zinc. It has fungistatic (inhibiting the division of fungal cells) and bacteriostatic (inhibiting bacterial cell division) properties and is used in the treatment of seborrhoeic dermatitis [ 2 ] and dandruff .
The English Pronouncing Dictionary (EPD) was created by the British phonetician Daniel Jones and was first published in 1917. [1] It originally comprised over 50,000 headwords listed in their spelling form, each of which was given one or more pronunciations transcribed using a set of phonemic symbols based on a standard accent.
Zinc compounds, like those of main group elements, are mostly colourless. Exceptions occur when the compound contains a coloured anion or ligand. However, zinc selenide and zinc telluride are both coloured due to charge-transfer processes. Zinc oxide turns yellow when heated due to the loss of some oxygen atoms and formation of a defect structure
The compound crystallizes in a tetragonal body-centered unit cell of space group symmetry I4 1 md. In the solid-state diethylzinc shows nearly linear Zn centres. The Zn-C bonds measure 194.8(5) pm, while the C-Zn-C angle is slightly bent with 176.2(4)°. [6]
Pyrithione is the common name of an organosulfur compound with molecular formula C 5 H 5 NOS, chosen as an abbreviation of pyridinethione, and found in the Persian shallot. [4] It exists as a pair of tautomers, the major form being the thione 1-hydroxy-2(1H)-pyridinethione and the minor form being the thiol 2-mercaptopyridine N-oxide; it crystallises in the thione form. [5]
Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity (electrowinning). Zinc is an essential trace element for humans, [8] [9] [10] animals, [11] plants [12] and for microorganisms [13] and is necessary for prenatal and postnatal development. [14]
Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn,Cu) 5 (CO 3) 2 (OH) 6. The zinc to copper ratio is about 5:4. [3] Copper (Cu 2+) gives aurichalcite its green-blue colors. [5]
4, with a central zinc atom in the +2 or (II) valence state coordinated to four hydroxide groups. It has Sp3 hybridization. It is the most common of the zincate anions, and is often called just zincate. These names are also used for the salts containing that anion, such as sodium zincate Na 2 Zn(OH) 4 [2] and calcium zincate CaZn(OH) 4 ·2H 2 O [3]