this may sound stupid but just read some history
after ottoman empire captured whole of armenia(armenia was part of iran or better to say was vassal) iran tried to get those lands back and was able to get half of it back(eastern armenia and karabakhand today azerbaijan) later the war between ottoman empire and iran weakens iran badly and the king of iran was a weak person as well.
after some time russia get these lands from iran(eastern armenia and karabakh and today azerbaijan)
this was the matter that created "east armenia" and "west armenia".actually it wasnt exist before this
i think this happened during qajar dynasty? im not sure but iran was very weak when it was ruled by turks and qajar was a turk dynasty
by the way iran was the only neighbor that ottoman empire couldnt capture and couldnt hold the captured lands for more than a year.thank goodness that there was no relation between iran and ottoman empire!