Can pi backdonation occur on non-metal centers?

The common example of back-donation is the interaction of a CO molecule with a metal center (d-orbitals) on a surface.

Can a similar mechanism occur between CO and a non-metal center, like oxygen on a surface (like in an oxide)? Can the p-orbitals of the surface oxygen be involved in such an interaction?

• It is a matter of perspective: back donation of pi-electrons is not limited to M-CO interactions. The more important question would be whether you would like to define it that way and look at it that way or not, and whether or not it will have a stabilising effect. (Related negative hyperconjugation) Carbon suboxide can certainly be explained that way: $\ce{O#C\bond{->}C\bond{<-}C#O <-> O=C=C=C=O}$ – Martin - マーチン May 8 at 15:19