The former Inter Milan and Chelsea manager has been linked with a number of high-profile names since taking the helm at the Bernabeu earlier this year, including star striker Adebayor, who was an unused substitute in Monday's 3-0 league victory over Liverpool.
However, speaking exclusively to Sky Sports News HD, the Portuguese boss admitted City's powerful financial position would make it near impossible to prise the 26-year-old away from Eastlands.
When asked about the possibility of signing the Togolese forward, Mourinho said: "I think no chance.
"The historical dimension of Real Madrid and Manchester City you can't compare. But the economical dimension you can compare.
"And maybe they will win (the Premier League).
"So I think at the minute Man City is the club to keep their best players and to buy the players that nobody expects them to buy.
"I don't think, just one year after buying Emmanuel from Arsenal, he's the player to leave."
Chelsea ace Didier Drogba is another striking star to be linked with a move to the Primera Liga giants, but Mourinho believes acquiring his signature is an equally unlikely prospect, adding: "Again, no chance."
Mourinho admits City are "dominant in the market" after outbidding the Spanish giants to sign Serbia full-back Aleksander Kolarov.
Kolarov joined City last month for £16million as part of another remarkable summer of team strengthening which has seen their Middle East owners plough more than £100m into the club.
And Mourinho, who joined Madrid after leading Inter Milan to a domestic and European treble last season, concedes even they can't compete.
"I understand that if someone wants to compete with them for a player it is very difficult, they are dominant in the market," he told Sky Sports News.
"The player they say they want is the player they get.
"I was interested in Kolarov when I came here but I couldn't compete with them as they went to values that I couldn't.
"If they have the money they can do it, if they have the ambition to win the Premier League they can do it."
Mourinho believes this season's Premier League title race is between City, Manchester United and his old club Chelsea.
"I believe Chelsea, Man United and Man City, that's it," he added, before dismissing the chances of Liverpool.
"It's very difficult for (new Liverpool manager) Roy Hodgson as over the last three years they have been getting worse, worse and worse. He needs time."