H. Nöth, B. Gemünd, R. T. Paine
FULL PAPER
by filtration and the solvents evaporated in vacuo. A slightly yellow
oil (0.5 g) remained as residue which decomposed on attempted
distillation. Yield 500 mg (65%). 1H NMR: δ = 0.15 (s, 3 H, BMe),
0.56 (s, 6 H, BMe), 4.42 ppm (br. s, 2 H, NH). 11B NMR: δ = 35.6,
37.9 ppm (1:2).
repeated crystallization from toluene/hexane at –20 °C. 1H NMR
(C6D6): δ = 0.18 (s, 3 H, BMe), 0.64 (d, 6 H, BMe), 4.55 ppm (br.
s, NH) ppm. 11B NMR (C6D6): δ = 35.7, 39.5 ppm (2:1). 31P NMR
(C6D6): δ = 120.3 ppm.
Tris(2,4,6-trimethylborazinyl)stibane (impure) was obtained as a
white powder upon treatment of a suspension of SbCl3 (0.488 g,
2.13 mmol) in hexane (20 mL) with a solution of 2 (1.30 g,
6.24 mmol) in hexane (30 mL). After heating the mixture overnight
to reflux and removing the insoluble material a white powder re-
mained after evaporation of the solvent. The product was charac-
terized only by NMR spectroscopy. 1H NMR: δ = 0.19 (s, 9 H,
Me), 0.52 (s, 18 H, Me), 4.31 ppm (s, 6 H, Me) and some additional
weak signals. 11B NMR: δ = 35.1, 37.3 ppm (1:2).
Chlorobis(2,4,6-trimethylborazinyl)arsane (8): Prepared in analogy
to 4 from AsCl3 (0.30 mL, 3.58 mmol) in hexane (30 mL) and 2
(1.45 g, 7.16 mmol) in toluene (20 mL). LiCl was recovered in 95%
yield. The filtrate was concentrated and the white amorphous pre-
cipitate that formed within a week was isolated. Yield 0.9 g (75%),
m.p. 64 °C. No single crystals were obtained from toluene, diethyl
ether, or thf solutions. C6H22AsB6ClN6 (353.49): calcd. C 20.38, H
6.27, N 23.37; found C 20.81, H 6.09, N 22.96. IR: ν = 3445 m,
˜
3419 s, 3411 s, 2942 s, 2951 s, 2909 s, 2858 m, 1478 s, 1397 s, 1303
s, 1285 s, 1193 m, 1177 m, 1161 m, 1154 m, 1118 w, 1083 m, 1045
w, 1026 w, 920 s, 889 s, 805 m, 753 w, 734 m, 717 s, 573 s, 539 m,
505 w, 485 w, 458 w, 430 w, 416 w, 344 m, 322 w, 288 w, 282 w, 274
w cm–1.
Bis(2,4,6-trimethylborazinyl)phosphane (13): Compound 6 (1.65 g,
4.67 mmol) was dissolved in hexane (30 mL) and a solution of Li-
AlH4 in diethyl ether (0.83 mL of a 1.3 solution) was added to
this stirred solution to give a white precipitate. After stirring over-
night the solid was removed by filtration and three quarters of the
solvents were evaporated from the filtrate in vacuo. Storing the
solution at +5 °C gave platelets of 13 within two weeks (m.p.
82 °C). Yield 0.95 g (75%). C6H23B6N6P (275.12): calcd. C 26.19,
Dichloro(2,4,6-trimethylborazinyl)stibane (9): Freshly sublimed
SbCl3 (0.60 g, 2.62 mmol) was suspended in hexane (30 mL) and a
solution of 2 (0.53 g, 1.57 mmol) in hexane (20 mL) was added.
After keeping the suspension at reflux overnight the insoluble white
material was removed by filtration. The solvent was evaporated
from the filtrate in vacuo and the residue dissolved in a small quan-
tity of hexane. Colorless crystals separated from this solution at
–5 °C within a week. Yield 0.62 g (75%), m.p. 148–149 °C.
C3H11B3Cl2N3Sb (314.23): calcd. C 11.47, H 3.53, Cl 22.56, N
H 8.43, N 30.54; found C 26.69, H 9.01, N 29.96. IR: ν = 3424 s,
˜
3402 s, 2958 s, 2942 s, 2932 s, 2846 w, 2489 w. 2293 s, 2254 s, 2175
w, 2122 w, 2080 w, 1980 w, 1915 w, 1901 w, 1879 w, 1483 s, 1397 s,
1371 m, 1316 s, 1291 s, 1206 m, 1196 m, 1186 w, 1163 s, 1143 w,
1105 w, 1093 w, 1065 m, 1040 w, 1021 w, 991 m, 962 s, 895 s, 834
w, 912 m, 785 w, 748 s, 725 w, 636 w. 605 m, 592 m, 572 m, 492 w,
479 w, 440 w, 394 w. 371 m, 356 w cm–1.
13.37; found C 12.86, H 3.84, Cl 22.34, N 12.48. IR: ν = 3448 w,
˜
3421 s, 3406 s, 2964 s, 2964 m, 2946 m, 2910 w, 1474 s, 1407 s,
1332 m, 1317 s, 1303 s, 1292 s, 1262 s, 1191 m, 1172 m, 1153 m,
1082 s, 1020 m, 889 s, 802 s, 757 m, 740 m, 715 s, 661 w, 569 s,
531 m, 400 w, 392 w, 342 s, 331 s, 318 st cm–1. MS (50 eV): m/z (%)
314 (5) [M+], 299 (45) [M+ – Me], 207 (20) [MeSbCl2+], 192 (100)
[SbCl2+], 156 (65) [SbCl+], 122 (80) [Me3B3N3H2+].
Zwitterionic Ethylphosphonium 2,4,6-Trimethylborazinate 14: A di-
ethyl ether solution of LiAlH4 (0.29 mmol, 1.4 ) was added to a
hexane solution (30 mL) of 5 (0.52 g, 1.66 mmol) with stirring. The
solid formed was removed by filtration after stirring the mixture
overnight. The volume of the filtrate was then reduced to one fifth.
Crystals separated within a week on storing this solution at –5 °C.
Yield 0.20 g (65%). C5H17B3N3P (182.59): calcd. C 32.89, H 9.37,
Tris(2,4,6-trimethylborazinyl)arsane was obtained from 2 (0.96 g,
4.69 mmol) in a solution of hexane (30 mL) and AsCl3 (0.11 mL,
1.56 mmol) in 10 mL of hexane. After keeping the mixture at reflux
for 3 d the solid was filtered off and the filtrate reduced to one
third of its original volume. The solution still contained small
amounts of chloride. The 11B NMR spectrum showed the forma-
tion of (Me3B3N3H2)3As. 1H NMR (C6D6): δ = 0.07 (s, 3 H, BMe),
0.61 (s, 6 H, BMe), 4.42 ppm (br. s, 2 H, NH) with some weak
signals from impurities. 11B NMR (C6D6): δ = 35.5, 36.9 ppm.
N 23.01; found C 32.19, H 9.12, N 22.54. IR: ν = 3443 s, 3407 s,
˜
2950 s, 2911 s, 2900 s, 2853 s, 2332 s, 1490 s, 1407 s, 1370 s, 1360
s, 1262 s, 1199 s, 1183 s, 1166 s, 1144 s, 1098 s, 1059 s, 1021 s, 997
s, 943 s, 888 s, 806 s, 748 s, 730 m, 715 m, 676 m, 667 m, 649 m,
642 m, 603 m, 567 m, 546 w, 397 w, 378 m cm–1. 1H NMR: δ =
0.14 (s, 3 H, BMe), 0.30 (m, 5 H, Et). 0.35–0.47 (m, 5 H, PMe,
PCH2), 0.54 (d, 4J
= 1.9 Hz, 6 H, BMe), 5.52 (dt, 1J
31P,1H
31P,1H
=
370, 3J31P,1H = 7 Hz, 2 H, PH2), 5.59 ppm (dq, 1J31P,1H = 379, 3J1H,1H
Chlorobis(2,4,6-trimethylborazinyl)stibane (10): A suspension of
SbCl3 (0.37 g, 1.62 mmol) in hexane (30 mL) was allowed to react
with a solution of 2 (0.657 g, 3.24 mmol) in hexane (20 mL). After
refluxing overnight the solid was removed by filtration and the fil-
trate reduced in volume by 3/4. From the solution settled a white
powder at –25 °C. Yield 0.50 g of 10 (75%), dec. Ͼ 200 °C.
C6H22B6ClN6Sb (400.36): calcd. C 17.99, H 5.53, N 20.99; found
= 7 Hz, 2 H, PH2). 11B NMR: δ = 34.1, 35.3 ppm. 31P NMR: δ =
1
31P,1H
5.5 ppm (t, J
= 430 Hz).
Bis(mesityl)bis(2,4,6-trimethylborazinyl)diphosphane (17): A solu-
tion of 6 (0.88 g, 25 mmol) in hexane (20 mL) was added slowly to
a stirred suspension of LiPmes2 (0.69 g, 2.5 mmol) in hexane
(50 mL) at –78 °C. The mixture was then kept at reflux for 14 h.
Insoluble material was removed by filtration and about half of the
solvent was removed in vacuo. The filtrate was kept at –25 °C and
the microcrystalline material recrystallized from toluene at –30 °C
as colorless prisms. Two crystals were selected for the X-ray struc-
ture determination and proved to contain toluene. The crystals be-
came opaque in vacuo. After keeping them in vacuo for 3 h the
yield was 1.15 g (85%), m.p. 182 °C. C24H44B6N6P2 (542.47): calcd.
C 20.47, H 5.38, N 21.79. IR: ν = 3438 s, 3418 s, 2963 s, 2932 m,
˜
2861 m, 2791 w, 1473 s, 1449 m, 1429 m, 1300 s, 1370 m, 1360 w,
1321 m, 1282 w, 1261 s, 1193 w, 1170 w, 1095 s, 1021 w, 956 w, 893
w, 833 w, 803 w, 755 w, 700 m, 670 m, 658 m, 614 s, 533 w, 528 w,
477 w, 404 w cm–1.
Tris(2,4,6-trimethylborazinyl)phosphane (11): PBr3 (1.64 mmol) dis-
solved in toluene (10 mL) was added to a solution of 2 (1.00 g,
4.93 mmol) in toluene (30 mL). A white precipitate formed rapidly. 53.04, H 8.16, N 15.46; found C 51.71, H 8.66, N 14.74. IR: ν =
˜
After keeping the mixture at reflux for one day the solid was re-
moved by filtration. A 31P NMR spectrum showed the formation
of 11 (δ = 120.3 ppm) along with minor amounts of 6 (δ =
191 ppm). The latter could not totally be removed from 6 despite
3424 m, 3414 m, 3403 w, 3100 w, 3089 m, 3025 m, 2965 s, 2924 s,
2864 m, 2731 w, 1667 w, 1601 m, 1549 w, 1478 s, 1432 s, 1396 m,
1298 s, 1277 s, 1188 m, 1178 m, 1152 m, 1083 m, 1031 w, 1016 w,
930 m, 896 m, 953 m, 861 m, 807 m, 787 w, 734 m, 699 w, 602 w,
4294
www.eurjic.org
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 4282–4297