The planet in question is this one. The atmosphere mainly consists of nitrogen and is approximately a quarter the density of Earth's; I chose surface temperatures ranging from -50°C to 0°C.
I need a compount which effectively "replaces" water on this planet. Any compounds similar to Water in their composition and their chemical reactions, with oxygen replaced by nitrogen, are welcome; I looked up Azanide (H2N) but could not find information about its chemical and physical properties.
A modification of the surface temperature is allowed, which means that compounds with evaporation temperatures between -100°C and -50°C are permitted too. The difference between the melting and evaporation temperature must be as big as possible.