Halogenation of (CF₃)₃B·NH₃:  N,N-Dihaloamino- and Halo-tris(trifluoromethyl)borates [(CF₃)₃B−NX₂]^- and [(CF₃)₃B−X]^-, X = F, Cl, Br

Abstract

(CF3)3B·NH3 (1) reacts with cesium hypochlorite or hypobromite to form the respective N,N-dichloroamino- or N,N-dibromoamino-tris(trifluoromethyl)borates Cs[(CF3)3B−NCl2] (2) or Cs[(CF3)3B−NBr2] (3). Fluorination of 2 or 3 in CH3CN yields Cs[(CF3)3B−NF2] (4) and Cs[(CF3)3B−F] (5). The fluorination reactions produce numerous byproducts; one of these, Cs[(CF3)3B−NH−COCBr3] (6), has been isolated from the reaction of 3. Compound 5 was also formed when 2 or 3 was treated with AgF2. Pyrolysis of 2 at 190 °C and 3 at 140 °C yielded the haloborates Cs[(CF3)3B−Cl] (7) and Cs[(CF3)3B−Br] (8), respectively. The constitution of the novel borates has been deduced from multinuclear NMR, IR, Raman, and mass spectra. The structures of 6, 7, 8, and Cs[(CF3)3B−NH2×(CF3)3B−NH3] (1a) have been investigated by single-crystal X-ray diffraction. 1a: C6H5B2CsF18N2, monoclinic, C2/c, a = 22.802(5) Å, b = 7.0965(13) Å, c = 11.000(2) Å, β = 102.79(2)°, Z = 4, R1 = 0.0374, wR2 = 0.0945. 6: C5HBBr3CsF9NO, monoclinic, C2/c, a = 20.121(4) Å, b = 16.765(3) Å, c = 10.005(2) Å, β = 118.416(12)°, Z = 8, R1 = 0.0680, wR2 = 0.1766. 7: C3BClCsF9, cubic, P213, a = 9.8059(9) Å, Z = 4, R1 = 0.0252, wR2 = 0.0639. 8: C3BBrCsF9, cubic, P213, a = 9.9001(14) Å, Z = 4, R1 = 0.0631, wR2 = 0.1490.

Salts of the Cobalt(I) Complexes [Co(CO)5]+ and [Co(CO)2(NO)2]+ and the Lewis Acid–Base Adduct [Co2(CO)7COB(CF3)3]

“…The proposed assignment of modes is in accordance with C 3 symmetry. The structural parameters are listed in Table 6 and allow a comparison of those of [(CF 3 ) 3 BCl] À , [41] [(CF 3 ) 3 BBr] À , [41] …”

[Co(CO)5][(CF3)3BF]: A Stable Salt of a Homoleptic Trigonal‐Bipyramidal Metal–Carbonyl Cation

“…[18,19] À ion are well known, but not structurally characterized to date. [20] The aim of this study was the synthesis of a salt with a homoleptic Co I -carbonyl cation. An early claim of the formation of [Co(CO) 5 ]…”

A Preparative Method for Perfluoroalkyltrifluoroborates and Perfluoroalkyldifluoroboranes

“…Using this procedure [(CF 3 ) n BF 4±n ] ± salts with n = 1, 2 were obtained. An alternative approach to trifluoromethylfluoroborates uses the oxidative fluorination of Cs[(CF 3 ) 3 BNX 2 ] (X = Cl, Br) with AgF 2 or fluorine [4]. Nevertheless, these methods seem to be limited to the preparation of the trifluoromethyl derivatives.…”