Sheikh Yâsîn al-Khatîb, professor at Umm al-Qurâ University
Ibn Taymiyah was asked a similar question so he replied [Majmû` al-Fatâwâ (31/368)] by saying:
As far as the divorce itself is concerned, it will take place as long as the husband is in full possession of his mental faculties and acts of his own choice. However, the woman will inherit from his estate, according to the opinion of the majority of the leading scholars of Islam. This is school of thought of Mâlik, Ahmad, and Abû Hanîfah, and it is the older opinion of al-Shâfi`î.
This was also the verdict implemented by the Caliph `Uthmân for the wife of `Abd al-Rahmân b. `Awf. `Abd al-Rahmân b. `Awf had divorced her in his death illness, but `Uthmân affirmed her share of his estate.
The woman has to observe the longest of the two waiting periods, whether it be the waiting period for divorce or death. However, if the husband had lost possession of his mental faculties, then his divorce is invalid from the outset.
Ibn Taymiyah was also asked about a man who, during his death illness, divorced his wife with a single pronouncement of divorce before consummation of the marriage. He was asked if it would be construed as a divorce to prevent her from her share of inheritance, legally necessitating that the opposite of his intentions be carried out and that she be granted her share of his estate and her full dowry. Or will she receive no share of the estate and only half of the dowry?
He replied [Majmû’ al-Fatâwâ (32/369)]:
There are two opinions among the scholars regarding the woman who is divorced before her marriage is consummated. The most correct one is that she is also entitled to inherit. This is the opinion of the school of thought of Mâlik and Ahmad – according to the well-known saying related from him – and that of al-Shâfi`î. This is because it was related that `Uthmân gave such a woman her share of the estate after her waiting period elapsed.
Such a woman only inherits on account of her right connected with the estate when the husband suffers from his death illness and consequently has his right to dispose of his property curtailed so that he may not transfer any of his wealth to those who are his inheritors not grant to non-inheritors more than a third of his estate, in the same way that he has no right to do so after his death. Since his right to dispose of his property during his death illness with respect to his inheritors is the same as it is after death, he consequently has no authority to prevent her from her share after falling ill. This is what the scholars call a divorce of avoidance.
This is the correct opinion that I also adopt.
And Allah knows best.
Source: Islam Today