I do know that NH3, ammonia, has long been a candidate, but the devil is in the details.
ammonia-based lifeIn 1954, J. B. S. Haldane, speaking at the Symposium on the Origin of Life, suggested that an alternative biochemistry could be conceived in which water was replaced as a solvent by liquid ammonia.1Part of his reasoning was based on the observation that water has a number of ammonia analogues. …
… On the down side, there are problems with the notion of ammonia as a basis for life. These center principally upon the fact that the heat of vaporization of ammonia is only half that of water and its surface tension only one third as much. Consequently, the hydrogen bonds that exist between ammonia molecule are much weaker than those in water so that ammonia would be less able to concentrate non-polar molecules through a hydrophobic effect. Lacking this ability, questions hang over how well ammonia could hold prebiotic molecules together sufficiently well to allow the formation of a self-reproducing system.
There’s another article I found that does a nice job of explaining the details.
Science Fiction Or Science Fact: Ammonia-Based Alien LifeBy Tom Caldwell
https: //treknews . net/2011/09/18/science-fiction-or-science-fact-ammonia-based-alien-life/
(delete the spaces)