Probably no. However several Papal Constitutions, from Honorius III to Innocent IV, Clement IV and Julius II, have repeatedly prohibited the possession of the Imperial title and of the Kingdom of Naples by the same sovereign, on pain of relegation of Naples to the Apostolic See...
For example, Leo X will use this prohibition for "not supporting" the election of Charles V [even if, when he will be elected, the Pope will not have problem to deliver to Charles the Bull of pantry for Naples].