Designated nomenclature

Packed Column Design Nomenclature References Problems... 

An alternative method to specify the relative orientation of groups in bridged compounds is called designated nomenclature. This is best described by examination of its use in naming the anticholinergic compound scopolamine, 9-methyl-3-oxa-9-azatricyclo[3.3.1.0 ]nonan-7-ol [(la,2p,4p,5a,7P)]. 

Locant (Section 2 12) In lUPAC nomenclature a prefix that designates the atom that is associated with a particular structural unit The locant is most often a number and the structural unit is usually an attached substituent as in... 

Complex linear polyamines are best designated by replacement nomenclature. These trivial names are retained aniline, benzidene, phenetidine, toluidine, and xylidine. 

The prefix sila- designates replacement of carbon by silicon in replacement nomenclature. Prefix names for radicals are formed analogously to those for the corresponding carbon-containing compounds. Thus silyl is used for SiH3—, silyene for —SiH2—, silylidyne for —SiH<, as well as trily, tetrayl, and so on for free valences(s) on ring structures. 

Classification of P2 purinoceptors has been limited by a lack of potent, selective, and bioavailable antagonists. Nonetheless a rational scheme for P2 purinoceptor nomenclature divides P2 receptors into two superfamilies P2Y5 LGIC family having four subclasses and P2Y) a GPCR family having seven subclasses. A third receptor type, designated the P22) is a nonselective ion pore. 

Berzehus (19) further appHed and amplified the nomenclature introduced by Guyton de Morveau and Lavoisier. It was he who divided the elements into metalloids (nonmetals) and metals according to their electrochemical character, and the compounds of oxygen with positive elements (metals) into suboxides, oxides, and peroxides. His division of the acids according to degree of oxidation has been Httie altered. He introduced the terms anhydride and amphoteric and designated the chlorides in a manner similar to that used for the oxides. 

The nomenclature (qv) of polyamides is fraught with a variety of systematic, semisystematic, and common naming systems used variously by different sources. In North America the common practice is to call type AB or type AABB polyamides nylon-x or nylon-respectively, where x refers to the number of carbon atoms between the amide nitrogens. For type AABB polyamides, the number of carbon atoms in the diamine is indicated first, followed by the number of carbon atoms in the diacid. For example, the polyamide formed from 6-aminohexanoic acid [60-32-2] is named nylon-6 [25038-54-4], that formed from 1,6-hexanediamine [124-09-4] or hexamethylenediamine and dodecanedioic acid [693-23-2] is called nylon-6,12 [24936-74-1]. In Europe, the common practice is to use the designation "polyamide," often abbreviated PA, instead of "nylon" in the name. Thus, the two examples above become PA-6 and PA-6,12, respectively. PA is the International Union of Pure and AppHed Chemistry (lUPAC) accepted abbreviation for polyamides. 

Carboxyhc acid nomenclature designates number of carbonsmumber of double bonds. For example, 10 0 indicates a fuUy saturated C q acid. 

Common names, chemical stmcture, and synonyms for the vitamins are given in Table 3. The names given to the vitamins and/or their letter designations do not foUow a logical pattern and are of historical significance only. Despite this, the nomenclature is in common use. 

Nomenclature is based on the keto-enol tautomers. The trihydroxy form is variously designated cyanuric acid, j -triaziae-2,4,6-triol or 2,4,6-trihydroxy-j -triaziQe. The trioxo stmcture, or j -triaziae-2,4,6(lJT,3JT,5JT)-trione is the basis for the isocyanuric acid nomenclature. 

FIG. 21-61 Typ es of pallets. Designations are standard designs based on nomenclature of tbe National Wooden Pallet and Container Association, Washington, D.C. Types 2B and 2C are used for bags and corrugated cartons. Type 3 is used for drums and pails. 

Ollis and Ramsden state that A compound may be appropriately called mesoionic if it is a five-membered heterocycle which cannot be represented satisfactorily by any one covalent or polar structure and possesses a sextet of electrons in association with the five atoms comprising the ring . From the point of view of systematic nomenclature, compounds of this type are difficult to deal with, since most available nomenclature systems are designed so as to name one particular bond- and charge-localized canonical form. 

---