精细化工专业英语.pptVIP

Alkenes and Alkynes IUPAC rules for naming alkenes and alkynes Aromatic Compounds * * Fine chemicals are products of high and well-defined purity, which are manufactured in relatively small amounts and sold at relatively high price. Although a question of taste, reasonable limits would be 10kton/year and $10/kg, fine chemicals can be divided in two basic groups: those are used as intermediates for other products, and those that by their nature have a specific activity and used based on their performance characteristics. Performance chemicals are used as active ingredients or additives in formulations, and as aids in processing. Translation 精细化学品具有高而且明确的纯度，批量小，但是价格却相对较高。尽管（对于精细化学品的年产量和单价）还有些争议，但是相对较为合理的范围应该是年产万吨，每千克售价10美元。精细化学品主要被分为两类，一类是生产其他产品的中间体，另一类是本身具有某种特殊的性能，并且它们的功能性特征得到了应用。功能性的化学品常被用作配方中的活性成分和添加剂，以及在加工过程中的助剂。 Alkenes (also known as olefins) contain at least one double bond between carbon atoms. The simplest alkene is ethene (or ethylene) Alkynes (also known as acetylenes) contain at least one triple bond between carbon atoms. The simplest alkyne is ethyne (or acetylene) Definition Select the longest carbon-carbon chain that contains the double or triple bond. Name this parent compound as you would name an alkane, but change the –ane to –ene for alkenes or to –yne for an alkynes. Number the carbon chain of the parent compound so that the double or triple bond carries the lowest possible number. Use the smaller of the two number on the double or triple bonded carbon atoms to indicate the position of the double or triple bond. Place this number in front of the alkene or alkyne name. Side chain and other groups are treated as in naming alkanes. The presence of both double and triple bonds is similarly denoted by endings such as “-enyne”, “-adienyne”, “-enediyne”, etc. Numbers as low as possible are given to double and triple bonds as a set, even though this may at times give “-yne” a lower number than “-ene”. If a choice remains, preference for low locants is