Mono- and Diazides of Bismuth - American Chemical Society

Dec 27, 2010 - ‡Leibniz-Institut f¨ur Katalyse e.V. an der Universit¨at Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany. Received Octobe...
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Organometallics 2011, 30, 284–289 DOI: 10.1021/om1009796

Mono- and Diazides of Bismuth Axel Schulz*,†,‡ and Alexander Villinger*,† †

Universit€ at Rostock, Institut f€ ur Chemie, Albert-Einstein-Str.3a, 18059 Rostock, Germany, and Leibniz-Institut f€ ur Katalyse e.V. an der Universit€ at Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany

‡

Received October 13, 2010

Bis[2-((dimethylamino)methyl)phenyl]azidobismuthane, [2-(Me2NCH2)C6H4]2BiN3, and [2-((dimethylamino)methyl)phenyl]diazidobismuthane, [2-(Me2NCH2)C6H4]Bi(N3)2, were synthesized and fully characterized. [2-(Me2NCH2)C6H4]2BiN3 and [2-(Me2NCH2)C6H4]Bi(N3)2 represent rare examples of bismuth azides. The structures of both azide compounds were determined by singlecrystal X-ray diffraction. While for the monoazide [2-(Me2NCH2)C6H4]2BiN3 a monomeric species was found, the diazide [2-(Me2NCH2)C6H4]Bi(N3)2 dimerizes in the solid state, exhibiting two bridging azido groups. Furthermore, weak van der Waals interactions between these centrosymmetric dimers lead to a chainlike structure in the crystal.

Introduction Azides of group 15 elements form a class of highly endothermic compounds. Numerous binary azides of the heavier group 15 elements arsenic and antimony have been reported and characterized (As(N3)3,1 [As(N3)4]þ,2 [As(N3)4]-,2 As(N3)5,3 [As(N3)6]-,2,4 Sb(N3)3,1c,5 [Sb(N3)4]þ,2 [Sb(N3)4]-,2 Sb(N3)5,3 [Sb(N3)6]-). Only recently binary bismuth azides of the type Bi(N3)3, [Bi(N3)4]-, and [Bi(N3)6]3- been reported.6 There is little known about organobismuth azides. As early as 1934 Challenger and Richards described the formation of Ph3Bi(N3)2, which was obtained in the reaction of Ph3BiCl2 and NaN3.7 When it is heated to 100 °C, Ph3Bi(N3)2 decomposes to give Ph2BiN3. Almost 40 years later Me2BiN3 was observed in the reaction of Me3Bi with HN3 and structurally characterized.8 Dehnicke studied BiON3 obtained from Bi(NO3)3 and NaN3 in water by means of IR spectroscopy.9 Ph3Bi(I)N3 was observed when IN3 was added to a solution of Ph3Bi.10 We started the search for high-nitrogen-content organobismuth-nitrogen compounds with mono- and diazido species, which are additionally stabilized by an aryl organic group bearing a donor Me2N donor function ([2-(Me2NCH2)C6H4]-). Following our interest in group 15 element nitro*Corresponding authors. E-mail: [email protected]. (1) (a) Klap€ otke, T. M.; Geissler, P. J. Chem. Soc., Dalton Trans. 19953365–3366. (b) Geissler, P.; Klap€otke, T. M.; Kroth, H.-J. Spectrochim. Acta, Part A 1995, 51, 1075–1078. (c) Haiges, R.; Vij, A.; Boatz, J. A.; Schneider, S.; Schroer, T.; Gerken, M.; Christe, K. O. Chem. Eur. J. 2004, 10, 508–517. (2) Karaghiosoff, K.; Klap€ otke, T. M.; Krumm, B.; N€ oth, H.; Schmitt, T.; Suter, M. Inorg. Chem. 2002, 41, 170–179. (3) Haiges, R.; Boatz, J. A.; Vij, A.; Vij, V.; Gerken, M.; Schneider, S.; Schroer, T.; Yousufuddin, M.; Christe, K. O. Angew. Chem. 2004, 116, 6844-6848; Angew. Chem., Int. Ed. 2004, 43, 6676-6680 (4) Klap€ otke, T. M.; N€ oth, H.; Schmitt, T.; Warchhold, M. Angew. Chem. 2000, 112, 2197-2199; Angew. Chem., Int. Ed. 2000, 39, 2108-2109. (5) Klap€ otke, T. M.; Schulz, A.; McNamara, J. J. Chem. Soc., Dalton Trans. 1996, 2985–2987. (6) Schulz, A.; Villinger, A. Angew. Chem., Int. Ed. 2010, 49, 8017–8020. (7) Challenger, F.; Richards, O. V. J. Chem. Soc. 1934, 405–411. uller, J. Z. Anorg. Allg. Chem. 1971, 381, 103–115. (8) M€ (9) Dehnicke, K. Z. Anorg. Allg. Chem. 1974, 409, 311–319. (10) Raj, P.; Singhal, E.; Rastogi, R. Polyhedron 1986, 5, 677–685. pubs.acs.org/Organometallics

Published on Web 12/27/2010

gen compounds with a high nitrogen content,11 we describe here the synthesis, isolation, and full characterization of diorganomonoazido and organodiazido bismuth compounds.

Results and Discussion Synthesis. Ligands with the potential for supplemental Lewis base interactions such as 2-((dimethylamino)methyl)phenyl12 are finding increasing utility for the stabilization of electrophilic main-group species such as trivalent compounds of the general formulas REX2 and R2EX (E = P, As, Sb, Bi; R = [2,6-(Me2NCH2)2C6H3]; X = halogen).13 For the synthesis of diorgano and monoorgano bismuth azide compounds the 2-((dimethylamino)methyl)phenyl group was chosen, which has already been successfully used for the generation of halogeno compounds [2-(Me 2 NCH 2 )C 6H 4 ]2 BiX and [2-(Me2NCH2)C6H4]BiX2 (X = Cl, I), respectively.14-16 (11) (a) Schulz, A.; Villinger, A. Inorg. Chem. 2009, 48, 7359–7367. (b) Baumann, W.; Schulz, A.; Villinger, A. Angew. Chem. 2008, 120, 9672-9675; Angew. Chem., Int. Ed. 2008, 47, 9530-9532. (c) Michalik, D.; Schulz, A.; Villinger, A.; Weding, N. Angew. Chem. 2008, 120, 6565-6568; Angew. Chem., Int. Ed. 2008, 47, 6465-6468. (d) Schulz, A.; Villinger, A. Angew. Chem. 2008, 120, 614-617; Angew. Chem., Int. Ed. 2008, 47, 603-606. (e) Mayer, P.; Schulz, A.; Villinger, A. Chem. Commun. 2006, 1236–1238. (f) Herler, S.; Villinger, A.; Mayer, P.; Schulz, A.; Weigand, J. J. Angew. Chem. 2005, 117, 7968-7971; Angew. Chem., Int. Ed. 2005, 44, 7790-7793. (12) (a) van Koten, G.; Leusink, A. J.; Noltes, J. G. J. Organomet. Chem. 1975, 84, 117–127. (b) Jones, F. N.; Hauser, C. R. J. Org. Chem. 1962, 27, 4389–4391. (c) Klein, K. P.; Hauser, C. R. J. Org. Chem. 1967, 32, 1479–1483. (13) (a) van Koten, G.; Jastrzebski, J. T. B. H.; Noltes, J. G.; Spek, A. L.; Schoone, J. C. J. Organomet. Chem. 1978, 148, 233–245. (b) Cowley, A. H.; Gabbai, F. P.; Atwood, D. A.; Carrano, C. J.; Mokry, L.; Bond, M. J. J. Am. Chem. Soc. 1994, 116, 1559–1560. (c) Contreras, L.; Cowley, A. H.; Gabbai, F. P.; Jones, R. A.; Carrano, C. J.; Bond, M. R. J. Organomet. Chem. 1995, 489, C1. (d) Isom, H. S.; Cowley, A. H.; Decken, A.; Sissingh, F.; Corbelin, S.; Lagow, R. J. Organometallics 1995, 14, 2400–2406. (e) Cowley, A. H.; Gabbai, F. P.; Isom, H. S.; Decken, A. J. Organomet. Chem. 1995, 500, 81–88. (14) Carmalt, C. J.; Cowley, A. H.; Culp, R. D.; Jones, R. A.; Kamepalli, S.; Norman, N. C. Inorg. Chem. 1997, 36, 2770–2776. (15) Breunig, H. J.; K€ onigsmann, L.; Lork, E.; Nema, M.; Philipp, N.; Silvestru, C.; Soran, A.; Varga, R. A.; Wagner, R. Dalton Trans. 2008, 1831–1842. (16) Kamepalli, S.; Carmalt, C. J.; Culp, R. D.; Cowley, A. H.; Jones, R. A. Inorg. Chem. 1996, 35, 6179–6183. r 2010 American Chemical Society

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Scheme 1. Synthesis of 1

Scheme 2. Synthesis of 2

Since the azido group should be introduced by an iodide-azide exchange reaction, in a first reaction step bis[2-((dimethylamino)methyl)phenyl]iodobismuthane, [2-(Me2NCH2)C6H4]2BiI (1), and [2-((dimethylamino)methyl)phenyl]diiodobismuthane, [2-(Me2NCH2)C6H4]BiI2 (2) were respectively prepared (Schemes 1 and 2). Both compounds 1 and 2 can easily be generated via the chloro species.14-16 Compound 1 is obtained when, to a stirred suspension of BiCl3, a suspension of [2-((dimethylamino)methyl)phenyl]lithium, [2-(Me2NCH2)C6H4]Li, was added in one portion at -80 °C followed by a chlorineiodine exchange (Scheme 1). The synthesis of 2 starts from tris[2-((dimethylamino)methyl)phenyl]bismuthane, [2(Me2NCH2)C6H4]3Bi (3),14 which is obtained when BiCl3 is treated with a suspension of [2-((dimethylamino)methyl)phenyl]lithium, [2-(Me2NCH2)C6H4]Li (Scheme 2). Reaction of 3 with 2 equiv of BiCl3 results in the formation of [2-(Me2NCH2)C6H4]BiCl2, which is easily transformed into the diiodo 2 species by a chlorine-iodine exchange.

The reactions of [2-(Me 2NCH2 )C6 H4 ]2BiI and [2(Me2NCH2)C6H4]BiI2 with a stoichiometric amount of silver azide, AgN3, in tetrahydrofuran (THF) solution at ambient temperature result in complete iodide-azide exchange and yield clear, colorless solutions of bis[2-((dimethylamino)methyl)phenyl]azidobismuthane, [2-(Me2NCH2)C6H4]2BiN3 (4), and [2-((dimethylamino)methyl)phenyl]diazidobismuthane, [2-(Me2NCH2)C6H4]Bi(N3)2 (5), respectively (Scheme 3). Filtration and removal of the solvent leads to the isolation of pure 4 and 5 in very good yields (4, 87%; 5, 98%). Azide formation in 4 and 5 can easily be detected by means of IR spectroscopy (νas(N3) 2022 (4), 2022 cm-1 (5)) and 14N NMR spectroscopy. Two well-resolved 14N NMR resonances were found in the spectra run in different solvents (due to low solubility) at 300 K for 4 (DMSO) and 5 (THF). As expected, both 14N solution spectra show a sharp signal at δ -134 (4, Δν = 77 Hz) and -134 (5, Δν = 53 Hz) ppm for the Nβ atoms (cf. Bi(N3)4- at -136 ppm (Δν = 43 Hz)) and a medium-sharp resonance at δ -275 (4, Δν = 570 Hz)

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Scheme 3. Synthesis of 4 (n = 2, x = 1) and 5 (n = 1, x = 2)

Figure 1. ORTEP drawing of the molecular structure of 1 in the crystal form. Thermal ellipsoids are shown at the 50% probability level, at 173 K. Selected bond lengths (A˚) and angles (deg): BiC10 = 2.259(2), Bi-C1 = 2.265(2), Bi-N1 = 2.522(2), Bi-I = 3.078(1); C10-Bi-C1 = 95.02(8), C10-Bi-N1 = 92.95(7), C1-Bi-N1 = 73.50(7), C10-Bi-I = 87.83(6), C1-Bi-I = 94.46(6), N1-Bi-I = 167.96(4).

and -262 (5, Δν = 390 Hz) ppm for the Nγ atoms (cf. Bi(N3)4at -253 (Δν = 480 Hz) ppm), in accord with known literature values for polar covalently bound azido groups.6,17 The observation of only one set of azide signals and the absence of the NR resonance indicate strong quadrupole relaxation effects and a rapid ligand exchange on the NMR time scale.18 The degree of polarity can be studied with the help of the shift for the Nγ atom, which indicates a larger degree of ionicity of the Bi-N3 bond for 4 due to a better intrinsic (donoracceptor) stabilization of the R2Biþ fragment (cf. 4 (-275 ppm) < 5 (-262 ppm) < Bi(N3)4- (-252 ppm)).6 Neither the mono- nor the diazide are heat or shock sensitive, and both are thermally stable to over 155 °C (4, 158 °C; 5, 159 °C). At this temperature decomposition starts without explosion. Both species are air-stable and soluble in common polar and nonpolar solvents. Compounds 4 and 5 can be prepared in bulk and are stable for long periods when stored in a sealed tube. X-ray Structure Analysis. The solid-state structures of the starting materials 1-3 are known.15,14,16 For comparison, and since we obtained considerably better data sets for 1 and especially for 3, we include our structural data (for 1 and 3) in the discussion. The molecular structures of 1 and 3 are shown in Figures 1 and 2 (details are given in Table S1 in the Supporting Information), and of the azide species 4 and 5 in Figures 3 and 4, respectively, along with selected bond lengths and angles. Crystallographic details are given in Table 1. More details are found in the Supporting Information. (17) Tornieporth-Oetting, I. C.; Klap€ otke, T. M. Angew. Chem. 1995, 107, 559-568; Angew. Chem., Int. Ed. 1995, 34, 511-520. (18) Berry, R. S. J. Chem. Phys. 1960, 32, 933–940.

Figure 2. ORTEP drawing of the molecular structure of 3 in the crystal form. Thermal ellipsoids are shown at the 50% probability level, at 173 K. Selected bond lengths (A˚) and angles (deg): Bi1-C1= 2.272(3), Bi1-C19 = 2.276(3), Bi1-C10 = 2.279(3), Bi-N1 = 3.052(3), Bi-N2 = 3.021(3), Bi-N3 = 3.074(2); C1-Bi1-C19 = 91.7(1), C1-Bi1-C10 = 95.5(1), C19-Bi1-C10 = 92.5(1).

Figure 3. ORTEP drawing of the molecular structure of 4 in the crystal form. Thermal ellipsoids are shown at the 50% probability level, at 173 K. Selected bond lengths (A˚) and angles (deg): Bi1-C10 = 2.244(3), Bi1-C1 = 2.248(3), Bi1-N1 = 2.413(2), Bi1-N5 = 2.555(2), Bi-N4 = 3.131(3), N1-N2 = 1.193(4), N2-N3 = 1.157(4), N4-C9 = 1.453(5), N4-C7 = 1.470(4), N4-C8 = 1.479(4), N5-C17 = 1.465(4), N5-C18 = 1.468(4), N5-C16 = 1.474(4); C10-Bi1-C1 = 95.1(1), C10Bi1-N1 = 87.3(1), C1-Bi1-N1 = 83.6(1), C10-Bi1-N5 = 73.01(9), C1-Bi1-N5 = 92.75(9), N1-Bi1-N5 = 159.58(9), N2-N1-Bi1 = 120.6(2), N3-N2-N1 = 177.6(3).

[2-(Me2NCH2)C6H4]2BiI (1) crystallizes in the monoclinic space group P21/n with four formula units per cell. The structure consists of separated [2-(Me2NCH2)C6H4]2BiI molecules with no significant intermolecular contacts.15 Only weak C-H 3 3 3 I interactions are found. Formally, the

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Table 1. Crystallographic Details of Azides 4 and 5

Figure 4. ORTEP drawing of the molecular structure of 5 in the crystal form. Thermal ellipsoids are shown at the 50% probability level, at 173 K. Selected bond lengths (A˚) and angles (deg): Bi-C1 = 2.249(2), Bi-N2 = 2.295(2), Bi-N5 = 2.387(2), Bi-N1 = 2.568(2), Bi-N50 = 2.726(2), N1-C9 = 1.462(4), N1-C8 = 1.471(4), N1-C7 = 1.473(4), N2-N3 = 1.156(3), N3-N4 = 1.159(3), N5-N6 = 1.199(3), N6-N7 = 1.143(3); C1-Bi-N2 = 91.62(8), C1-Bi-N5 = 89.19(9), N2-Bi-N5 = 84.53(8), C1-Bi-N1 = 72.34(9), N2-Bi-N1 = 82.14(8), N5Bi-N1 = 156.79(7), C1-Bi-N50 = 88.35(8), N2-Bi-N50 = 152.43(7). N5;Bi-N50 =67.90(8), N1-Bi-N50 =123.78(7), N3N2-Bi = 123.9(2), N6-N5-Bi = 115.7(2), N6-N5-Bi0 = 125.4(2), Bi-N5-Bi0 = 112.10(8), N2-N3-N4 = 176.4(3), N7N6-N5 = 178.9(3). Symmetry code (0 ): -x þ 1, -y þ 1, -z þ 2.

central bismuth atom is tetracoordinated (Figure 1); however, the Bi-I distance amounts to 3.078(1) A˚, which is P rather long compared to the sum of the covalent radii rcov(Bi-I) = 2.83 A˚.19 In BiI3(s) a Bi-I distance of 3.07 A˚20 is found with Bi in an octahedral environment (cf. 2.807(6) A˚ in BiI3(g)).21 Hence, an ionic situation as found for BiI3(s),22 that is, [R2Bi]þ[I]-, might also be discussed. Here the [R2Bi]þ cation is stabilized by an additional Bi-N1 donor-acceptor bond with one of the adjacent NMe2 groups, as indicatedPby a short Bi-N1 distance (d(Bi-N1) = 2.522 (2), cf. rcov(Bi-N) = 2.2 A˚).17 This Bi-N1 bond isPconsiderably longer than the sum of the covalent radii rcov(Bi-N) but still significantly shorter P than the sum of the van der Waals radii rvdW(Bi-N) = 4.0 A˚.17 For the second NMe2 moiety only weak van der Waals interactions can be assumed, since the Bi-N2 distance is found at 3.158(2) A˚. The angles around the trigonalpyramidal Bi center are all between 75 and 95° (C1-BiN1 = 73.50(7) to C10-Bi-C1 = 95.02(8)°). Compound 3 crystallizes in the space group P21 with four molecules per unit cell and two independent molecules per asymmetric unit.14 Although not required crystallographically, (19) Holleman Wiberg. Lehrbuch der Anorganischen Chemie, 102nd ed.; Walter de Gruyter: Berlin, 2007; Suppl. IV. (20) Trotter, J.; Zobel, T. Z. Kristallogr. 1966, 123, 67–72. (21) Molnar, J.; Kolonits, M.; Hargittai, M.; Konings, R. J. M.; Booij, A. S. Inorg. Chem. 1996, 35, 7639–7642. (22) Margaritondo, G.; Stoffel, N. G.; Levy, F. Solid State Commun. 1979, 29, 797–799.

chem formula formula wt color cryst syst space group a (A˚) b (A˚) c (A˚) V (A˚3) Z Fcalcd (g cm-3) μ (mm-1) λ Mo KR (A˚) T (K) no. of measd rflns no. of indep rflns no. of rflns with I > 2σ(I ) Rint. F(000) R1 (R(F2 > 2σ(F2))) wR2(F2) GOF no. of params

4

5

C18H24BiN5 519.40 colorless monoclinic P21/n 8.558(4) 16.135(7) 13.864(6) 1914.3(15) 4 1.802 9.219 0.710 73 173(2) 8505 4154 3566 0.0197 1000 0.0198 0.0464 1.020 221

C18H24Bi2N14 854.47 colorless monoclinic P21/c 11.895(6) 7.544(4) 14.235(8) 1244.3(12) 2 2.281 14.159 0.710 73 173(2) 18 391 4494 3882 0.0395 792 0.0201 0.0503 1.051 156

both independent molecules of 3 possess approximate C3 symmetry. The primary coordination sphere consists of a trigonal-pyramidal BiC3 skeleton with three secondary interactions between the pendant amines and the bismuth center. While the average Bi-C bond length of P 2.276 A˚ lies in the range of a typical covalent bond (cf. rcov(Bi-C) = 2.27 A˚),17 the Bi 3 3 3 N distances between 3.02 and 3.08 A˚ indicate only van der Waals interactions; however, these contacts are slightly shorter compared to that found in 1 at 3.158(2) A˚ and are significantly longer compared to the short Bi-N1 donor-acceptor bond in 1 (d(Bi-N1) = 2.522 (2) A˚; see Figures 1 and 2). The monoazide 4 crystallizes in the monoclinic space group P21/n with four formula units per cell. The asymmetric unit consists of a [2-(Me2NCH2)C6H4]2BiN3 molecule. As depicted in Figure 3, the BiC2N2 core of 4 is distorted bisphenoidal with a N1-Bi-N5 angle of 159.58(9)° and a C1-Bi-C10 angle of 95.09(1)°. As already discussed, two significantly different Bi-NMe2 distances with d(Bi1-N5) = 2.555(2) A˚ (cf. 1 at 2.522(2) A˚) and d(Bi-N4) = 3.131 A˚ (cf. 1 at 3.158(2) A˚ and 3 at an average of 3.049 A˚) are observed, displaying a strong donor-acceptor bond P for Bi-N5 and a van der Waals contact for Bi-N4 (cf. rvdW(Bi-N) = 4.0 ˚ A˚).17 The Bi-Nazide distance (d(Bi-N1) = 2.413(2) P A) represents the shortest Bi-N bond length in 4 (cf. rcov(Bi-N) = 2.2 A˚). Similar structural features are found for the [Bi(N3)4]- ion, which also adopts a distorted-bisphenoidal geometry with two shorter (2.273(2) and 2.291(2) A˚) and two longer Bi-N bond lengths (2.377(2) and 2.449(2) A˚).6 As shown on numerous occasions,23 covalently bound azide groups such as in 4 display a trans-bent configuration (regarding the Bi atom, Bi-NNN) with N-N-N bond (23) For example: (a) M€ uller, U. Chem. Ber. 1977, 110, 788–791. (b) Roesky, H. W.; Noltemeyer, M.; Sheldrick, G. M. Z. Naturforsch., B 1986, 41, 803–807. (c) Schomburg, D.; Wermuth, U.; Schmutzler, R. Chem. Ber. 1987, 120, 1713–1718. (d) Cowley, A. H.; Gabbai, F.; Schluter, R.; Atwood, D. J. Am. Chem. Soc. 1992, 114, 3142–3144. (e) Englert, U.; Paetzold, P.; Eversheim, E. Z. Kristallogr. 1993, 208, 307–309. (f) Cowley, A. H.; Gabbai, F. P.; Bertrand, G.; Carrano, C. J.; Bond, M. R. J. Organomet. Chem. 1995, 493, 95–99. (g) Larbig, M.; Nieger, M.; v. d. G€onna, V.; Ruban, A. V.; Niecke, E. Angew. Chem., Int. Ed. Engl. 1995, 34, 460–462. (h) Schranz, I.; Grocholl, L. P.; Stahl, L.; Staples, R. J.; Johnson, A. Inorg. Chem. 2000, 39, 3037–3041.

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Figure 5. View of the molecular structure of 5 showing the chains of dimers.

angles of 177.6(3) and 120.6(2)° along the N2-N1-Bi moiety. Diazido compound 5 crystallizes in the monoclinic space group P21/c with four formula units per cell. The asymmetric unit consists of a [2-(Me2NCH2)C6H4]Bi(N3)2 molecule; however, in contrast to 4 it has significant symmetric intermolecular interactions (d(Bi-N50 ) = 2.726(2) A˚) leading to the formation of a centrosymmetric {[2-(Me2NCH2)C6H4]2BiN3}2 dimer (Figure 4). Moreover, these dimers interact further via a weak symmetric P interaction involving N2 (d(Bi 3 3 3 N200 ) = 3.080(2) A˚; cf. rvdW(Bi-N) = 4.0 A˚),17 as shown in Figure 5; if these interactions are considered, the overall Bi coordination geometry is strongly distorted octahedral. Hence, the crystal structure of 5 can be described as a weakly bound polymer of more strongly bound centrosymmetric dimers. Also, for the [Bi(N3)4]- ion an expansion of the Bi coordination number by the formation of nitrogen bridges involving R-nitrogen atoms of two of the azido ligands is observed, leading to infinite zigzag chains in the crystal. Here the Bi-Nbridge distances amount to 2.684(2) and 2.717(2) A˚, respectively.6 Oligomeric structures have been previously reported for bismuth halides of the type [{2-(6-Me)C5H3N}NSiMe3]BiCI24 and several heteroleptic and homoleptic bismuth(III) amidinate halide complexes.25,26 The [2-(Me2NCH2)C6H4]Bi(N3)2 molecule adopts a distorted-bisphenoidal geometry. Upon dimerization via N5 a planar Bi2N2 ring with two shorter (d(Bi-N5) = 2.387(2) A˚) andP two longer Bi-N bond lengths (d(Bi-N50 ) = 2.568(2) A˚; cf. rcov(Bi-N) = 2.2 A˚) is formed, which represents the most prominent structural feature.17 The shortest Bi-N bond length is found for Bi-N2 at 2.295(2) A˚ (cf. 4 at 2.413(2) A˚). The Bi-NMe2 donor-acceptor bond (d(Bi-N1) = 2.568(2) A˚) is in the range of those found for 4 (2.555(2) A˚) and 1 (2.522(2) A˚), respectively. For both azido ligands the typical trans-bent structure with NNN angles of about 176-179° is observed. The NR-Nβ bonds range between 1.156(3) and 1.199(3) A˚, and Nβ-Nγ bond lengths between 1.159(3) and 1.143(3) A˚ are found, in accord with our expectation.1-6

Conclusion New organobismuth(III) monoazido and diazido compounds containing the supplemental Lewis base arm ligand 2-(Me2NCH2)C6H4 were prepared and fully characterized (24) Raston, C. L.; Skelton, B. W.; Tolhurst, V.-A.; White, A. H. Polyhedron 1998, 935–942. (25) Brym, M.; Forsyth, C. M.; Jones, C.; Junk, P. C.; Rose, R. P.; Stascha, A.; Turner, D. R. Dalton Trans. 2007, 3282–3288. (26) Lyhs, B.; Schulz, S.; Westphal, U.; Bl€aser, D.; Boese, R.; Bolte, M. Eur. J. Inorg. Chem. 2009, 2247–2253.

Schulz and Villinger

for the first time. While the monoazide compound 4 crystallizes as a [2-(Me2NCH2)C6H4]2BiN3 molecule with no significant intermolecular contacts, the diazido species can be best described as a polymer of weakly bound centrosymmetric dimers. In both azide compounds one strong intramolecular donor-acceptor interaction between the bismuth center and the nitrogen atom of one adjacent NMe2 moiety is observed. Moreover, for 4 only very weak van der Waals interactions can be assumed between the second NMe2 group and the Bi center. If this second (weak) intramolecular NfBi interaction is considered, the overall coordination becomes distorted square pyramidal ((C,N)2BiN3 core); otherwise, it is distorted bisphenoidal. For 5 a distorted-octahedral environment can be discussed.

Experimental Section General Information. All manipulations were carried out under oxygen- and moisture-free conditions under argon using standard Schlenk or drybox techniques. Dichloromethane was purified according to a literature procedure,27 dried over P4O10, and freshly distilled prior to use. Tetrahydrofuran (THF), toluene, and diethyl ether were dried over Na/benzophenone and freshly distilled prior to use. n-Pentane and n-hexane were dried over Na/benzophenone/tetraglyme and freshly distilled prior to use. Ethanol was freshly distilled prior to use. Bismuth triiodide, BiI3 (99%, Merck), was dried at 120 °C prior to use. Bismuth trichloride (BiCl3; 99%, anhydrous, Alfa Aesar), NaI (Fluka, 99%), silver nitrate (AgNO3; 99%, VEB Feinchemie Sebnitz), sodium azide (99%, Acros), and tetraphenylphosphonium iodide ([Ph4P]I; 99%, Aldrich) were used as received. Silver azide (AgN3) was dried at 70 °C for several days prior to use. [2-((Dimethylamino)methyl)phenyl]lithium ([2-(Me2NCH2)C6H4]Li) was prepared according to literature procedures;12 bis[2-((dimethylamino)methyl)phenyl]chlorobismuthane ([2-(Me2NCH2)C6H4]2BiCl),14 bis[2-((dimethylamino)methyl)phenyl]iodobismuthane ([2-(Me2NCH2)C6H4]2BiI),15 tris[2-((dimethylamino)methyl)phenyl]bismuthane ([2(Me2NCH2)C6H4]3Bi),16 [2-((dimethylamino)methyl)phenyl]dichlorobismuthane ([2-(Me2NCH2)C 6H4]BiCl2),14 and [2((dimethylamino)methyl)phenyl]diiodobismuthane ([2-(Me2NCH2)C6H4]Bil2)14 have been reported previously and were prepared according to modified procedures. 13 C{1H}, 13C DEPT, and 1H NMR spectra were obtained on a Bruker AVANCE 500 spectrometer and were referenced internally to the deuterated solvent (13C: CD2Cl2, δreference 54 ppm; C4D8O, δreference 67.2 ppm) or to protic impurities in the deuterated solvent (1H: CDHCl2, δreference 5.31 ppm; C4D7HO, δreference 3.57 ppm). CD2Cl2 was dried over P4O10, and C4D8O was dried over Na/benzophenone. IR spectra were obtained on a Nicolet 380 FT-IR spectrometer with a Smart Orbit ATR device. Raman spectra were obtained on a Bruker VERTEX 70 FT-IR spectrometer with a RAM II FT-Raman module, equipped with a Nd:YAG laser (1064 nm). Solid samples were sealed off in small glass tubes. CHN analyses were obtained with an Analysator Flash EA 1112 instrument from Thermo Quest or a C/H/ N/S-Mikronalysator TruSpec-932 from Leco. Melting points are uncorrected (EZ-Melt, Stanford Research Systems). The heating rate was 20 °C/min (clearing points are reported). DSC measurements were obtained on a DSC 823e instrument from Mettler-Toledo (heating rate 5 °C/min). MS was obtained on a Finnigan MAT 95-XP instrument from Thermo Electron. HRMS was obtained on a 6210 time-of-flight LC/MS instrument from Agilent Technologies (MeOH/0.1% HCOOH in H2O 90/10). (27) Fischer, C. B.; Xu, S.; Zipse, H. Chem. Eur. J. 2006, 12, 5779– 5784.

Article X-ray Structure Determination. X-ray-quality crystals were selected in Fomblin YR-1800 perfluoroether (Alfa Aesar) at ambient temperatures. The samples were cooled to 173(2) K during measurement. The data were collected on a Bruker Apex Kappa-II CCD diffractometer using graphite-monochromated Mo KR radiation (λ = 0.710 73 A˚). The structures were solved by direct methods (SHELXS-97)28 and refined by full-matrix least-squares procedures (SHELXL-97).29 Semiempirical absorption corrections were applied (SADABS).30 All non-hydrogen atoms were refined anisotropically; hydrogen atoms were included in the refinement at calculated positions using a riding model. Synthesis of [2-(Me2NCH2)C6H4]2BiN3 (4). To a stirred solution of [2-(Me2NCH2)C6H4]2BiI (0.770 g, 1.27 mmol) in THF (20 mL) was added silver azide (AgN3; neat, 0.210 g, 1.40 mmol) in one portion at ambient temperature. The resulting yellowish suspension was stirred for 15 h. The resulting off-white suspension was filtered (F4), and the solution was concentrated in vacuo to an approximate volume of 3 mL. Slow cooling to 25 °C resulted in the deposition of colorless crystals. Removal of the supernatant by decantation and drying in vacuo yielded 0.578 g (1.11 mmol, 87%) of [2-(Me2NCH2)C6H4]2BiN3 (4) as colorless crystals. Mp: 158 °C dec. Anal. Calcd (found): C, 41.62 (41.80); H, 4.66 (4.52); N, 13.48 (13.47). 1H NMR (25 °C, CD2Cl2, 500.13 MHz): δ 2.33 (s, 12H, CH3), 3.67 (s, 4H, CH2), 7.41 (td, 2H, CH, 3J(1H-1H) = 7.3 Hz, 4J(1H-1H) = 1.4 Hz), 7.45 (td, 2H, CH, 3J(1H-1H) = 7.3 Hz, 4J(1H-1H) = 1.4 Hz), 7.53 (dd, 2H, CH, 3J(1H-1H) = 7.3 Hz, 4J(1H-1H) = 1.4 Hz), 8.24 (dd, 2H, CH, 3J(1H-1H) = 7.3 Hz, 4J(1H-1H) = 1.4 Hz). 13C{1H} NMR (25 °C, CD2Cl2, 125.76 MHz): δ 46.0 (CH3), 68.3 (CH2), 128.8 (CH), 130.6 (CH), 131.4 (CH), 139.5 (CH), 147.0, 183.6. IR (ATR, 32 scans, cm-1): 3047 (w), 3009 (w), 2988 (w), 2957 (w), 2928 (w), 2894 (w), 2862 (m), 2837 (w), 2817 (m), 2784 (m), 2022 (s), 1471 (m), 1452 (s), 1437 (m), 1417 (w), 1406 (w), 1362 (w), 1352 (w), 1319 (s), 1299 (m), 1267 (m), 1246 (s), 1203 (m), 1171 (m), 1157 (m), 1146 (w), 1111 (m), 1070 (w), 1140 (m), 1031 (m), 1018 (s), 1006 (s), 974 (s), 948 (m), 882 (w), 842 (s), 829 (s), 759 (s), 722 (w), 709 (w), 668 (w), 647 (w), 639 (m), 610 (m). Raman (200 mW, 25 °C, 500 scans, cm-1): 3065 (5), 3049 (10), 3038 (7), 3020 (3), 3008 (3), 2998 (3), 2978 (6), 2958 (4), 2927 (3), 2893 (5), 2865 (5), 2838 (6), 2825 (5), 2785 (6), 2709 (1), 2683 (1), 2022 (3), 1579 (5), 1566 (3), 1470 (3), 1458 (3), 1439 (4), 1406 (1), 1363 (1), 1353 (5), 1320 (2), 1302 (3), 1275 (2), 1249 (3), 1204 (3), 1167 (2), 1152 (2), 1112 (1), 1052 (5), 1042 (4), 1019 (5), 976 (1), 953 (1), 885 (1), 844 (2), 829 (1), 759 (1), 723 (1), 710 (1), 648 (6), 616 (1), 515 (2), 497 (1), 447 (4), 423 (1), 384 (1), 349 (8), (28) Sheldrick, G. M. SHELXS-97: Program for the Solution of Crystal Structures; University of G€ottingen: G€ottingen, Germany, 1997. (29) Sheldrick, G. M. SHELXL-97: Program for the Refinement of Crystal Structures; University of G€ottingen, G€ottingen, Germany, 1997. (30) Sheldrick, G. M. SADABS, Version 2; University of G€ottingen, G€ ottingen, Germany, 2004.

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284 (2), 264 (4), 221 (1), 201 (4), 180 (5), 157 (6), 132 (2), 114 (4). MS (EI, m/z, >5%): 42 (20.7), 43 (17.7), 58 (84.8) [NMe3 - H]þ, 65 (15.3), 91 (88.8) [C7H7]þ, 118 (11.9), 132 (36.5), 134 (100) [C9H12N]þ, 178 (11.0), 209 (56.8) [Bi]þ, 342 (7.76), 343 (54.4) [C9H12NBi]þ, 418 (5.91) [Bi2]þ, 477 (58.6) [(C9H12N)2Bi]þ, 627 (3.64) [Bi3]þ, 836 (5.99) [Bi4]þ. HRMS (ESIþ, m/z): calcd (found) C9H11BiN [M - H - N3 - C9H12N]þ 343.069 53 (342.068 67), C18H24BiN2 [M -N3]þ 477.174 33 (477.179 64). Crystals suitable for X-ray crystallographic analysis were obtained directly from the above THF solution of 4. Synthesis of [2-(Me2NCH2)C6H4]Bi(N3)2 (5). To a stirred solution of [2-(Me2NCH2)C6H4]Bil2 (0.298 g, 0.5 mmol) in THF (15 mL), was added silver azide (AgN3; neat, 0.165 g, 1.1 mmol) in one portion at ambient temperature. The resulting yellow suspension was stirred for 12 h, resulting in an off-white suspension. Filtration (F4) and removal of solvent in vacuo yielded 0.210 g (0.492 mmol, 98%) of [2-(Me2NCH2)C6H4]Bi(N3)2 (5) as a colorless, microcrystalline solid. Mp: 159 °C dec. Anal. Calcd (found): C, 25.30 (25.93); H, 2.83 (2.81); N, 22.95 (22.08). 1H NMR (25 °C, THF-d8, 500.13 MHz): δ 2.56 (s, 12H, CH3), 4.12 (s, 4H, CH2), 7.44 (td, 2H, CH, 3J(1H-1H) = 7.4 Hz), 7.67 (td, 2H, CH, 3J(1H-1H) = 7.4 Hz), 7.78 (dd, 2H, CH, 3J(1H-1H) = 7.4 Hz), 8.71 (dd, 2H, CH, 3J(1H-1H) = 7.4 Hz). 13C{1H} NMR (25 °C, THF-d8, 125.76 MHz): δ 44.9 (CH3), 68.6 (CH2), 128.8 (CH), 129.4 (CH), 130.6 (CH), 131.4 (CH), 139.0, 150.6. IR (ATR, 32 scans, cm-1): 3328 (w), 3281 (w), 3055 (w), 3033 (w), 2995 (w), 2967 (w), 2862 (w), 2835 (m), 2793 (w), 2688 (w), 2640 (s), 2570 (w), 2513 (w), 2022 (s), 1458 (m), 1435 (m), 1407 (w), 1352 (w), 1310 (s), 1262 (s), 1196 (m), 1172 (m), 1155 (w), 1145 (w), 1109 (m), 1100 (m), 1033 (m), 1012 (s), 972 (m), 950 (w), 873 (w), 841 (s), 823 (s), 753 (s) 708 (w), 667 (w), 644 (s), 616 (w), 599 (s). Raman (50 mW, 25 °C, 107 scans, cm-1): 3060 (3), 3036 (3), 3011 (2), 2970 (3), 2954 (2), 2943 (2), 2897 (3), 2870 (3), 2841 (3), 2798 (2), 2761 (1), 2071 (10), 2036 (5), 1581 (2), 1566 (2), 1461 (2), 1382 (2), 1354 (4), 1318 (1), 1291 (2), 1269 (2), 1244 (2), 1200 (2), 1176 (2), 1163 (1), 1043 (4), 1022 (2), 968 (1), 846 (1), 826 (1), 797 (1), 648 (3), 572 (1), 548 (1), 500 (2), 467 (2), 444 (2), 389 (1), 355 (4), 322 (6), 276 (3), 262 (3), 224 (2), 198 (6), 133 (9), 110 (5). MS (EI, m/z, >5%): 43 (18.1), 58 (21.1) [NMe3 - H]þ, 91 (59.4) [C7H7]þ, 118 (7.67), 132 (37.7), 134 (100) [C9H12N]þ, 209 (51.9) [Bi]þ, 336 (10.9), 343 (35.3) [C9H12NBi]þ, 378 (15.9), 385 (10.0), 418 (3.79) [Bi2]þ, 477 (46.7) [(C9H12N)2Bi]þ, 627 (3.42) [Bi3]þ, 836 (5.22) [Bi4]þ. Crystals suitable for X-ray crystallographic analysis were obtained by cooling a hot THF solution of 5 slowly to ambient temperature. Supporting Information Available: Text, figures, and tables giving additional synthetic details and CIF files giving crystal structure data. This material is available free of charge via the Internet at http://pubs.acs.org.