An interesting title popped up in my feed the other day: Chelsea R Martinez and Brent L Iverson’s Perspective article ‘Rethinking the term pi-stacking’ (Chem. Sci., 2012, DOI: 10.1039/C2SC20045G). I don’t think I’d ever thought much about pi-stacking if I’m honest; the concept seemed to make sense and it just got absorbed into my brain along with those other concepts that I now find are mutable, like hydrogen bonds.
I’ll leave the complexities of the argument to the paper, but considering that pi-pi interactions seem so ubiquitous, especially in biological and supra molecular chemistry, where do they say we’ve been going wrong? Essentially, the point Martinez and Iverson make is that just because interactions involve pi-bonds doesn’t make them inherently different from other interactions. For example, they discuss alternating electron rich and deficient aromatic systems. Is that face centred stacking really special, or is it just normal donor-acceptor chemistry?
So what do you think, and what other contentious chemistries do you enjoy debating?