Grand Duke Henri and Grand Duchess Maria-Teresa will be state visiting Turkey later this year. The visit will take place between November 20 and 22.
While I'm a little unsure about all the details, I can tell you that the Grand Duke is scheduled to attend an economic and financial seminar at the Çırağan Palace in Istanbul on the 21st and that there will be a reception in the presence of Grand Duke Henri and Grand Duchess Maria-Teresa on the same day at the same venue. I'm assuming that the couple will also visit Ankara, Turkey's capital, to meet with some politicians.
Source: Luxembourg for Finance