Final answer:
The 'sideways' bonding of olefins to transition metals is explained using Valence Bond Theory's description of pi bonds and Molecular Orbital Theory's account of in-phase and out-of-phase combinations of atomic wave functions. VSEPR Theory predicts molecular shapes but isn't specific to this interaction, and Lewis Dot Structures offer a basic representation without detailed orbital interactions.
Step-by-step explanation:
Bonding Theories and Transition Metals
The question addresses how olefins bond "sideways" to transition metals. This can be explained through different theoretical frameworks in chemistry such as Molecular Orbital Theory, Valence Bond Theory, and VSEPR Theory.
In Valence Bond Theory, a pi (π) bond is described as having a nodal plane that contains the internuclear axis, perpendicular to the lobes of the p orbitals, with electron density on each side of the node. This is how the sideways overlap of two p orbitals in olefins is accounted for, enabling them to bond with transition metals.
Molecular Orbital Theory provides a different perspective by describing molecular orbitals as combinations of atomic wave functions that can be in-phase (bonding) or out-of-phase (antibonding). In this case, p orbitals that are oriented side-by-side form π bonding molecular orbitals with electron density on opposite sides of the internuclear axis, which is consistent with the bonding seen in transition metal complexes with olefins.
VSEPR Theory does not directly describe the interaction between transition metals and olefins but is useful for predicting the shapes of molecules by considering repulsions between electron pairs.
Lastly, Lewis Dot Structures provide a simple representation of bonding by depicting electrons as dots around atoms, but they are less informative about the actual orbital interactions in transition metal complexes with olefins.
To fully describe and understand these interactions, we often rely on both Molecular Orbital and Valence Bond Theories, sometimes integrating concepts from VSEPR as well.