Since the dawn of organometallic chemistry, transition metal complexes of unsaturated organic molecules, namely π-complexes, have remained a central focus: our thorough understanding of the electronic nature of such species, and their importance in countless reactive processes continues to drive research in their synthesis and utilisation. Since the late 1900s, research regarding the related chemistry for the heavier group 14 elements has become increasingly more fervent. Today, heavier congeners of a vast array of classical π-complexes have been realised, from alkene to arene systems, involving Si, Ge, Sn, and Pb. This has given deeper insights into the bonding observed for these heavier elements, which typically involves a lessened degree of π-bonding and an increased polarisation. This review aims to summarise this field, identifying these disparities, and highlighting areas which we believe may be exciting for future exploration.

自从配位有机金属化学诞生以来，过渡金属与不饱和有机分子形成的配合物（即π-配合物）一直是研究的重点。我们对这类物种的电子性质的深入了解及其在众多反应过程中的重要性持续推动了它们合成和应用的研究进展。自20世纪末以来，关于第14族较重元素相关化学的研究日益激烈。如今，从烯烃到芳烃系统，涉及Si、Ge、Sn和Pb的一系列经典π-配合物的较重同系物已经被实现。这为这些较重元素的键合性质提供了更深入的理解，通常涉及到较少的π-键合和更多的极化作用。本综述旨在总结这一领域的研究，并识别其中的差异，同时强调我们认为未来可能具有探索价值的领域。