Novel Organotellurium(IV) Diazides and Triazides

Abstract

New series dialkyltellurium(IV) diazides R(2)Te(N(3))(2) (R = CH(3) (6), C(2)H(5) (7), n-C(3)H(7) (8), i-C(3)H(7) (9), c-C(6)H(11) (10)) and alkyl/aryltellurium(IV) triazides R'Te(N(3))(3) (R' = CH(3) (11), C(2)H(5) (12), n-C(3)H(7) (13), i-C(3)H(7) (14), C(6)H(5) (15), 2,4,6-(CH(3))(3)C(6)H(2) (16)) were synthesized by the straightforward substitution of fluorine atoms in the corresponding tellurium difluorides, or trifluorides respectively, with trimethylsilyl azide. In addition to standard characterization methods, the first crystal structures of covalent organotellurium(IV) triazides 12, 13, 14, and 16 have been determined. Ethyltellurium(IV) triazide, C(2)H(5)Te(N(3))(3) (12), crystallizes in the monoclinic space group P2(1)/n, a = 8.4530(2) A, b = 7.9094(2) A, c = 12.6288(3) A, beta = 91.876(1). n-Propyltellurium(IV) triazide, n-C(3)H(7)Te(N(3))(3) (13), crystallizes in the monoclinic space group P2(1)/n as well, a = 8.7999(2) A, b = 7.9674(2) A, c = 13.2334(3) A, beta = 94.626(1). Isopropyltellurium(IV) triazide, i-C(3)H(7)Te(N(3))(3) (14), crystallizes in the monoclinic space group C2/c, a = 20.058(2) A, b = 6.9620(3) A, c = 15.030(1) A, beta = 114.260(9). Mesityltellurium(IV) triazide, 2,4,6-(CH(3))(3)C(6)H(2)Te(N(3))(3) (16), crystallizes monoclinic as well; the space group is P2(1)/c, a = 7.5503(6) A, b = 23.581(1) A, c = 7.5094(6) A, beta = 91.295(9). The structures and vibrational frequencies of the methyl derivatives dimethyltellurium(IV) diazide (6) and methyltellurium(IV) triazide (11) have been calculated by density functional theory methods and were compared with the experimental metric parameters and vibrational data.

Polyazide Chemistry: Preparation and Characterization of Te(N3)4 and [P(C6H5)4]2[Te(N3)6] and Evidence for [N(CH3)4][Te(N3)5]

“…The other extreme, that is the presence of highly covalent azido ligands, is found in the [Te(N 3 ) 3 ] + ion [5] and RTe(N 3 ) 3 (R = Et, nPr, iPr, or 2,4,6-Me 3 C 6 H 2 ). [12] In these compounds, the TeÀN bond lengths range from 1.99 to 2.25 , and the N a ÀN b and N b ÀN g lengths differ by about 0.1 . As might be expected, …”

“…It is, therefore, not surprising that polyazides are highly endothermic compounds, and that their energy content increases with an increasing number of azido ligands. Compared to the relatively stable azide anion, which possesses two double bonds, the bonds in covalent azides are polarized towards a single and a triple bond, which greatly facilitates N 2 elimination and enhances their shock sensitivity.Consequently, the synthesis and characterization of covalent binary azides containing multiple azido ligands can present great experimental challenges, and binary tellurium azides are no exception to this general rule.Whereas numerous, partially azide-substituted tellurium compounds have been reported, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] only one binary tellurium azide, the [Te(N 3 ) 3 ] + ion, has previously been reported. [5] In this paper, we wish to communicate the synthesis and characterization of three novel binary tellurium azides, In the presence of catalytic amounts of CsF, the reaction of TeF 6 with excess (CH 3 ) 3 SiN 3 in acetonitrile solution at room temperature results in the reduction of Te VI to Te IV , while the azide ion is oxidized to dinitrogen.…”

“…Whereas numerous, partially azide-substituted tellurium compounds have been reported, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] only one binary tellurium azide, the [Te(N 3 ) 3 ] + ion, has previously been reported. [5] In this paper, we wish to communicate the synthesis and characterization of three novel binary tellurium azides, In the presence of catalytic amounts of CsF, the reaction of TeF 6 with excess (CH 3 ) 3 SiN 3 in acetonitrile solution at room temperature results in the reduction of Te VI to Te IV , while the azide ion is oxidized to dinitrogen.…”

Binary Tellurium(IV) Azides: Te(N3)4 and [Te(N3)5]−

“…The groups of Wiberg and Passmore have indicated the possible existence of a highly explosive Te(N 3 ) 4 and warned of their potential danger. In pursuit of our recent efforts to explore the chemistry of covalent and ionic tellurium azides, [5,6] we describe here the synthesis, isolation, and properties of Te(N 3 ) 4 (1), [7] , the latter containing a rare pentacoordinated polyazido anion, the only other example being the [Fe(N 3 ) 5 ] 2À ion. [8] As is known from the syntheses of TeCl 3 (N 3 ) and TeCl 2 (N 3 ) 2 , [3] and confirmed by our own studies, treatment of TeCl 4 with excess Me 3 SiN 3 does not result in the substitution of all chlorine atoms.…”

“…In the course of the preparation of such a proposed pyridine·TeF 4 adduct, the results of the crystalstructure determination unexpectedly revealed a complex mixture of pyridinium pentafluorotellurate(iv) and dimeric units of TeF 4 solvated by pyridine. [13] Since crystals of 2 a grown from the reaction solution tend to deliquesce very rapidly, crystallization was attempted from solutions of the mixture of pyridine with TeF 4 5 ] À ion represents the first structurally characterized anionic tellurium azide. [7] Similar to neutral organotellurium(iv) azides, [5, 6a] secondary Te···N interactions below the sum of the van der Waals radii (3.61 ) [14] create network structures, which result in the octacoordinated tellurium atoms in 2 b (Figure 2).…”