All praises are due to Allah.
According to the Sunnah of Prophet Muhammad (p.b.u.h), no, it is not allowed to give money to the poor for Zakatul-Fitr.
The food permissible to give are: wheat, barley, dried dates, raisings and cottage cheese according to the reported Hadith from Abdullah biun ‘Umar (may Allah be please with him) that he said: “The Messenger of Allah (p.b.u.h.) obligated Zukatul-Fitr as a Sa’ of dried dates or a Sa’ of barley upon the slave and the free man, the male and female, and the child and the adult among the Muslims. He commanded that it be given before the people come to the prayer.” Al-Bukhari and Muslim.
And another hadith from Abu Sa’id (May Allah be please with him) that he said:
“We used to give it (Zakatul-fitr) in the time of the Prophet (p.b.u.h.) as a Sa’ of food or (i.e. meaning) a Sa’ of dried dates or a Sa’ of barley or a Sa’ of raisins.” In another narration he said” “and a Sa’ of cottage cheese.” Al-Bukhari and Muslim.
Some scholars say that these five types of food were specified because they were being used at that time. Therefore, they permit giving whatever food is common food of the land, like rice and corn in the land where it is used as food.
Allah knows best.