The triel bond may be defined as the interaction of the atom of 13th group that acts as the Lewis acid centre with the electron rich site of the species playing a role of the Lewis base. This interaction is often classified as the π-hole bond. Similar kinds of Lewis base sites occur for triel bonds and for hydrogen bonds. The following types of hydrogen bonds are discussed in different studies: A-H…B, A-H…π and A-H…σ interactions; A-H is the proton donating bond while B, π and σ mark a kind of proton acceptor: the mono-atomic Lewis base centre, the π-electrons and the σ-electrons, respectively. The triel centre, T, may also interact with such electron rich sites thus T…B, T…π and T…σ triel bonds may be identified. Different coordination of triel centres is discussed and corresponding examples of crystal structures taken from the Cambridge Structural Database are presented. The tetrahedral arrangements that obey the octet rule occur most frequently and they are characterised by the energetic stability. However trivalent and hypovalent triel structures that are characterised by the trigonal coordination as well as hypervalent triel structures possessing trigonal bipyramid and octahedral configurations occur in crystal structures frequently; other configurations are also discussed.

Triel键可以定义为充当路易斯酸中心的第13族原子与起路易斯碱作用的物质的富电子位点之间的相互作用。这种相互作用通常被归类为π孔键。类似的路易斯碱位点出现在三键和氢键上。在不同的研究中讨论了以下类型的氢键：AH…B，AH…π和AH…σ相互作用；AH是质子给体键，而B，π和σ表示一种质子受体：单原子的Lewis基中心，分别为π电子和σ电子。Triel中心T也可能与这些富电子位点相互作用，因此可以确定T…B，T…π和T…σtriel键。讨论了triel中心的不同配位，并给出了来自Cambridge Structural Database的晶体结构的相应示例。遵循八位字节规则的四面体排列最频繁发生，并且其特征在于能量稳定性。然而，具有三角配位特征的三价和次价三价结构以及具有三角双锥体和八面体构型的超价三价结构经常出现在晶体结构中。还讨论了其他配置。然而，具有三角配位特征的三价和次价三价结构以及具有三角双锥体和八面体构型的高价三价结构经常出现在晶体结构中。还讨论了其他配置。然而，具有三角配位特征的三价和次价三价结构以及具有三角双锥体和八面体构型的高价三价结构经常出现在晶体结构中。还讨论了其他配置。