一种确定氧化数的新方法

氧化数是元素的重要性质,在无机化学中应用广泛。长期以来,确定元素氧化数主要根据桐山良一和鲍林等建立的规则,这些规则对于氧化数概念在化学中的推广普及起了很大的作用,但在遇到结构复杂或未知化合物时有时仍然会出现问题。本文根据IUPAC的氧化数定义提出,氧化数完全取决于成键两原子之间的电子供需关系,元素的最高正氧化数受到其原子价层电子数的限制,而元素的最低负氧化数受到同周期稀有气体元素外层电子数与其价层电子数差值的限制,据此建立了确定元素氧化数的新方法,该方法既不需要考虑分子结构,也不依赖元素氧化数的习惯规定,符合氧化数概念提出的初衷,简便易行,例外情况少,不仅适合大学化学教学,也适合中学化学教学。

A New Method for Determining the Oxidation Number

Oxidation number is an important property of elements and widely applied in inorganic chemistry. The assignment of oxidation number was traditionally based on a set of rules founded by Ryōichi Kiriyama and Linus Pauling. These rules play important roles in the popularization of oxidation numbers in inorganic chemistry. But these initial rules would not work when dealing the compounds with complicated and unknown structures. According to the definition of oxidation number by IUPAC, a new method for determining the oxidation number based on the oxidation number depending entirely on the electron supply and demand relationship between the bonding two atoms is proposed here. The highest positive oxidation number of an element is limited by the number of electrons in its valence layer, and the lowest negative oxidation number of the element is limited by the difference between the number of electrons around the rare gas element and the number of valence layers in the same period. This method requires no information about molecule structure or initial rules of oxidation number. Furthermore, it is simple with few exceptions and can be used in high school and college chemistry teaching.