Why is the water solubility of CO worse than that of CO2? I tried my best to ask SciFinder, Google, and Google Scholar the wrong questions ...
I found many paper on the fitting of the solubility to some equations to be able to calculate the amount of $\ce{CO}$ in water, but I could hardly find any explanation on the low solubility. Only one paper [1] dealt with it.
Why is $\ce{CO}$ way less soluble in water than $\ce{CO2}$, despite, e.g., the first having a dipole moment and the latter doesn't? What am I missing?

[1] H. Sato, N. Matubayasi, M. Nakahara, F. Hirata, &quot;Which carbon oxide is more soluble? Ab initio study on carbon monoxide and dioxide in aqueous solution,&quot; Chemical Physics Letters 2000, 323(3-4), 257–262 (https://doi.org/10.1016/S0009-2614(00)00508-X).
The fact that $\ce{CO2}$ does not have a dipole moment does not really mean it's nonpolar.  What $\ce{CO2}$ has is a quadrupole, two opposing dipoles that occupy different portions of space (opposite sides of the carbon atom).
Ordinarily we expect an electrostatic interaction with a quadrupole to be relatively weak, but in $\ce{CO2}$ the component dipoles are strong and at close range the water molecules can &quot;home in&quot; on one end of the molecule and interact selectively with the corresponding component dipole.  Thereby the electrostatic interaction between water and the $\ce{CO2}$ quadrupole is stronger than the interaction between water and the weak $\ce{CO}$ dipole.