It can form salts with large cations such as tetramethylammonium nitratoborate,[1] or tetraethylammonium tetranitratoborate.
[2] Other related ions are the slightly more stable tetraperchloratoborates, with perchlorate groups instead of nitrate, and tetranitratoaluminate[3] with the next atom down the periodic table, aluminium instead of boron ([Al(NO3)4]−).
[2] Another mechanism to make tetranitratoborate salts is to shake a metal nitrate with BCl3 in chloroform at 20 °C for several days.
The infrared spectrum of tetramethylammonium nitratoborate includes a prominent line at 1,612 cm−1 with shoulders at 1582 and 1,626 cm−1 attributed to v4.
Also prominent is 1,297 and 1,311 cm−1 attributed to v1, with these vibrations due to the nitrate bonded via one oxygen.