Karen, I haven't grown "Coppertina," but it is a cross between the "Diablo" and "Darks Gold" ninebarks, and I have grown "Diablo," The more sun the better. I had two in full sun and one in a fair amount of shade and the ones in full sun were substantially more vigorous and had stronger coloration. It's good that you have room because they will definitely get big.

I agree with Douglas. They will survive in the shade but more sun the better. And if they are under a large tree, regular watering may be necessary especially if newly planted or transplanted.