I know the Romans celebrated their conquered cities through commemorative coins! I also know that the Ottoman coins lack any imagery so, were there any descriptions of the event in any of their coins? Or did they even consider the historical significance of conquering Constantinople?
They did consider it significant. Mehmet the conqueror was determined to take Constantinople for Islam even before his reign and the death of his father the sultan. His generals advised otherwise. There is a good series available on Netflix "The Ottomans" which illustrates the rise of Mehmet and the fall of Constantinople despite the efforts of Constantine XI and the Genoese. They only had a force of 6,000 men to defend the city. Here's the trailer: