The relevance of the Dewar model to neighboring p-block element analogs of metal hydrocarbon π-complexes

The existence of p-block element analogs of transition metal hydrocarbon π-complexes presents opportunities to examine the appropriateness of the Dewar model in describing the metal–main group η2-bonding interaction. Geometric structures and molecular orbital descriptions of electronic structures reveal both similarities and differences in the mutual perturbation of the metal and main group atom centers. Literature examples containing boron, silicon and phosphorus are used to illustrate the point in detail and the variety of metallaborane analogs of larger hydrocarbon π-complexes illustrates the scope of possibilities.