Halogenation of (CF3)(3)B center dot NH3: N,N-dihaloamino- and halo-tris (trifluoromethyl)borates [(CF3)(3)B-NX2](-) and [(CF3)(3)B-X](-), X = F, Cl,Br
Dj. Brauer et al., Halogenation of (CF3)(3)B center dot NH3: N,N-dihaloamino- and halo-tris (trifluoromethyl)borates [(CF3)(3)B-NX2](-) and [(CF3)(3)B-X](-), X = F, Cl,Br, INORG CHEM, 38(18), 1999, pp. 3972-3977
(CF3)(3)B . NH3 (1) reacts with cesium hypochlorite or hypobromite to form
the respective N,N-dichloroamina- or N,N-dibromoamino-tris(trifluoromethyl)
borates Cs[(CF3)(3)B-NCl2] (2) or Cs[(CF3)(3)B-NBr2] (3). Fluorination of 2
or 3 in CH3CN yields Cs[(CF3)(3)B-NF2] (4) and Cs[(CF3)(3)B-F] (5). The fl
uorination reactions produce numerous byproducts; one of these, Cs[(CF3)(3)
B-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 degree
s C and 3 at 140 degrees C. yielded the haloborates Cs[(CF3)(3)B-Cl] (7) an
d Cs[(CF3)(3)B-Br] (8), respectively. The constitution of the novel berates
has been deduced from multinuclear NMR, IR, Raman, and mass spectra. The s
tructures of 6, 7, 8, and Cs[(CF3)(3)B-NH2 x (CF3)(3)B -NH3] (1a) have been
investigated by single-crystal X-ray diffraction. 1a: C6H5B2CSF18N2, monoc
linic, C2/c, a = 22.802(5) Angstrom, b = 7.0965(13) Angstrom, c = 11.000(2)
Angstrom, beta = 102.79(2)degrees, Z = 4, R1 = 0.0374, wR2 = 0.0945. 6: C5
HBBr3CsF9NO, monoclinic, C2/c, a = 20.121(4) Angstrom, b = 16.765(3) Angstr
om, c = 10.005(2) Angstrom, beta = 118.416(12)degrees, Z = 8 R1 = 0.0680, w
R2 = 0.1766. 7: C3BClCsF9, cubic, P2(1)3, a = 9.8059(9) Angstrom, Z = 4, R1
= 0.0252, wR2 = 0.0639, 8: C3BBrCsF9, cubic, P2(1)3, a = 9.9001(14) Angstr
om, Z = 4, R1 = 0.0631, wR2 = 0.1490.