含有大π键(亦称为离域π键)的体系称为共轭体系,具有大π键的分子称为共轭分子。理论与实践证明,含有大π键的体系比较稳定,因此,分子或原子团中力图形成较多的、较大的(多原子的)大π键。在众多的无机化合物中,有相当一部分分子或离子为共轭分子,它们的结构不能用经典的结构式表示,只能应用大π键的概念来加以处理。下面我们简单介绍判断无机共轭分子结构的一般方法。 1.首先应用价键理论(杂化轨道理论或价层电子对互斥理论)将分子中各原于以σ键构成具有一定几何形状的分子骨架;若分子中各原子均在同一平面内(即中心原子以sp或sp~2杂化轨道键)。则有可能形成大π键;反之, A system containing a large π bond (also called a delocalized π bond) is called a conjugated system, and a molecule with a large π bond is called a conjugated molecule. Theory and practice have proven that systems containing large pi bonds are relatively stable, and therefore, molecules or atom groups tend to form larger, larger (polyatomic) pi bonds. Among a large number of inorganic compounds, a considerable number of molecules or ions are conjugated molecules whose structures cannot be represented by classical structural formulae and can only be handled using the concept of large π bonds. Below we briefly introduce the general method for determining the structure of inorganic conjugated molecules. 1. The first to apply the bond theory (hybrid orbit theory or valence electron pair mutex theory) will make each molecule in the molecule a skeleton with a certain geometric shape with sigma bonds; if the molecules in the molecule are in the same plane ( That is, the central atom has sp or sp~2 hybridized orbital bonds). It is possible to form a large π bond;