# Is there any actually observed excited state of a "hypervalent" main-group molecule that actually involves d-orbitals?

It is well known that, even in periods 3 and higher, the bonding in so-called "hypervalent" main-group molecules nearly always do not involve d-orbitals, and I've heard that it's because the d-orbitals are just too high in energy.

I now have a question: if the energetic difference is the only problem, then can bonds involving d-orbitals exist ("exist" as in "actually be observed") in excited states of "hypervalent" molecules?

For a more concrete example- do the bondings in sulfonate groups in Brilliant Blue FCF and indigo carmine get "elevated" from S(-O)3 to S(=O)2(-O) (charges omitted and S=O bonds involving sulfur's 3d orbitals) as they absorb red-light (opposite of blue) photons, and, if they do, to what extent?

One candidate involves calcium, of all things. This paper by Krieck et al. [1] reports the synthesis of a dimeric calcium(I) complex $$\ce{[(thf)3Ca\{μ-C6H3-1,3,5-Ph3\}Ca(thf)3]}$$ in which the calcium atoms are bonded to each other and there are two unpaired electrons in antibonding orbitals of the aromatic ring system.