Tetranitratoborate
Tetranitratoborate is an anion composed of boron with four nitrate groups. It has formula [B(NO3)4]−. It can form salts with large cations such as tetramethyl ammonium nitratoborate,[1] or tetraethyl ammonium tetranitratoborate.[2]
The ion was first discovered by C. R. Guibert, M. D. Marshall in 1966 after failed attempts to make neutral (non-ionic) boron nitrate.[1]
The related molecule, boron nitrate B(NO3)3, has resisted attempts to make it, and if it exists it is unstable above −78 °C.[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]−).
Formation
Tetramethyl ammonium chloride reacts with BCl3 to make (CH3)4NBCl4. Then the tetrachloroborate is reacted with N2O4 at around −20 °C to form tetramethyl ammonium nitratoborate, and other gases such as NO2Cl and Cl2.[2]
Another mechanism to make tetranitratoborate salts is to shake a metal nitrate with BCl3 in chloroform at 20 °C for several days. Chloronitratoborate [Cl3BNO3]− is an unstable intermediate.
- MNO3 + BCl3 → M[Cl3BNO3]
- 4M[Cl3BNO3] → 3M[BCl4] + MB(NO3)4][4]
Properties
The infrared spectrum of tetramethyl ammonium 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.[1]
The density of tetramethyl ammonium nitratoborate is 1.555. It is colourless and crystalline. As tetramethyl ammonium nitratoborate is heated it has some sort of transition between 51 and 62 °C. It decomposes above 75 °C producing gas. Above 112 °C it is exothermic, and a solid is left if it is heated to 160 °C.[2]
Tetramethyl ammonium nitratoborate is insoluble in cold water but slightly soluble in hot water. It does not react with water. It also dissolves in liquid ammonia, acetonitrile, methanol, and dimethylformamide.[1] It reacts with liquid sulfur dioxide.[1][5]
At room temperature tetramethyl ammonium nitratoborate is stable for months. It does not explode with impact.[1]
Alkali metal tetranitratoborates are unstable at room temperature and decompose.[4]
1-Ethyl-3-methyl-imidazolimium tetranitratoborate was discovered in 2002. It is an ionic liquid that turns solid at −25 °C.[6]
References
- Guibert, C. R.; M. D. Marshall (1966). "Synthesis of the Tetranitratoborate Anion". Journal of the American Chemical Society. 88 (1): 189–190. doi:10.1021/ja00953a051. ISSN 0002-7863.
- Titova, K. V.; V. Ya. Rosolovskii (1970). "Tetraalkylammonium nitratoborates". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 19 (12): 2515–2519. doi:10.1007/BF00854900. ISSN 0568-5230.
- Jones, CJ Bigler (2007). Transition and Main Group Metals Applied to Oxidative Functionalization of Methane and Use as High Oxygen Carriers for Rocket Propellants. ProQuest. p. 139. ISBN 9780549231066. Retrieved 3 February 2014.
- Titova, K. V.; V. Ya. Rosolovskii (1975). "Reaction of nitrates of monovalent cations with BCl3". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 24 (10): 2246–2248. doi:10.1007/BF00929774. ISSN 0568-5230.
- C.C. Addison and D. Sutton. Progress in Inorganic Chemistry. 8. p. 216.CS1 maint: uses authors parameter (link)
- Jones, C. Bigler; Ralf Haiges; Thorsten Schroer; Karl O. Christe (2006). "Oxygen-Balanced Energetic Ionic Liquid". Angewandte Chemie International Edition. 45 (30): 4981–4984. doi:10.1002/anie.200600735. ISSN 1433-7851. PMID 16819744.
HNO3 | He | ||||||||||||||||
LiNO3 | Be(NO3)2 | B(NO 3)− 4 |
RONO2 | NO− 3 NH4NO3 |
HOONO2 | FNO3 | Ne | ||||||||||
NaNO3 | Mg(NO3)2 | Al(NO3)3 | Si | P | S | ClONO2 | Ar | ||||||||||
KNO3 | Ca(NO3)2 | Sc(NO3)3 | Ti(NO3)4 | VO(NO3)3 | Cr(NO3)3 | Mn(NO3)2 | Fe(NO3)2 Fe(NO3)3 |
Co(NO3)2 Co(NO3)3 |
Ni(NO3)2 | CuNO3 Cu(NO3)2 |
Zn(NO3)2 | Ga(NO3)3 | Ge | As | Se | Br | Kr |
RbNO3 | Sr(NO3)2 | Y(NO3)3 | Zr(NO3)4 | Nb | Mo | Tc | Ru(NO3)3 | Rh(NO3)3 | Pd(NO3)2 Pd(NO3)4 |
AgNO3 Ag(NO3)2 |
Cd(NO3)2 | In | Sn | Sb(NO3)3 | Te | I | Xe(NO3)2 |
CsNO3 | Ba(NO3)2 | Hf | Ta | W | Re | Os | Ir | Pt(NO3)2 Pt(NO3)4 |
Au(NO3)3 | Hg2(NO3)2 Hg(NO3)2 |
TlNO3 Tl(NO3)3 |
Pb(NO3)2 | Bi(NO3)3 BiO(NO3) |
Po(NO3)4 | At | Rn | |
FrNO3 | Ra(NO3)2 | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og | |
↓ | |||||||||||||||||
La(NO3)3 | Ce(NO3)3 Ce(NO3)4 |
Pr(NO3)3 | Nd(NO3)3 | Pm(NO3)3 | Sm(NO3)3 | Eu(NO3)3 | Gd(NO3)3 | Tb(NO3)3 | Dy(NO3)3 | Ho(NO3)3 | Er(NO3)3 | Tm(NO3)3 | Yb(NO3)3 | Lu(NO3)3 | |||
Ac(NO3)3 | Th(NO3)4 | PaO2(NO3)3 | UO2(NO3)2 | Np(NO3)4 | Pu(NO3)4 | Am(NO3)3 | Cm(NO3)3 | Bk | Cf | Es | Fm | Md | No | Lr |