Hello Tam,
We do have the ability to move a DC that is empty (IE: has no devices to manage) from one IP Domain to another.
But the DC must be empty of all devices to manage. Doesn't matter whether the items are deleted or they are moved to another DC in the existing IP Domain the DC is tied to. Once its empty it should be able to be moved to another IP Domain.
A problem you may face here though is a limitation with moving the device items and their related elements. There is no way to move a device across IP Domains. That ability would be an Enhancement Request.
Thanks,
Mike