Money went to Iran because they were holding Qatari royal (read: Muslim Brotherhood/Ikhwan) hostages and one of their capture Syrian proxy forces:
businessinsider.com/qatar-ransom-al-qaeda-iran-falconry-2017-6
>A ransom payment of up to $1 billion to Iranian and Al Qaeda-linked forces in Syria may have been the tipping point for Qatari-Gulf Arab relations, Financial Times reported Monday.
>Qatar paid out the hefty ransom to secure the release of 26 members of a falconry party, some of whom were members of Qatar's royal family who had been hunting in southern Iraq, "commanders of militant groups and government officials in the region" told Financial Times.
Qatar has an interesting history with their relationship with the other Gulf states. The Al-Thani family is not widely respected because the current Emir's father, Hamad, engaged in a coup against his own father, Khalifa, who (COINCIDENTALLY was in Switzerland when it happened) a big cultural no no.
Other fun Middle East facts: The British deposed the Sultan of Oman, Said III, in favor of his son, Qaboos bin Said, who is a pedophile.