Kijów (yes, it actually was part of Polish Crown, not Commonwealth)
I don't need to use google to find the correct spelling of Київ*, but I did feel the need to use Cyrillic because there is no yi in any of the Latin alphabets I checked. I think the Latynka would be Kijiv, but, taking my cue from the majority of Ukrainians, I resist Latynka as much as I resist the Russified form, Kiev.
Now that I've looked a bit harder, I've found an i with diaeresis, so in future, when directly addressing you on the subject of the Capital of Ukraine, I'll write Kiïv so that you don't have to trouble your poor little head over funny foreign letters. To everybody else, I'll continue to use Cyrillic, since you seem to be the only person who has such a struggle.
Good spot, if I'd actually used google I'd have got it right :-) Not the first time I've written і when I should have written и
However, yi (ї) in Ukrainian is not the same as ye (e/є) in Russian/Ukrainian, and for that reason Russian pronunciation of Киев is not the same as Ukrainian pronunciation of Київ
Kijów (yes, it actually was part of Polish Crown, not Commonwealth)