Structural studies on aryl bismuth halides and halogenoanions. Part 4. Neutral Lewis base adducts of aryl bismuth dibromide and diaryl bismuth bromide compounds

Syntheses, structures, and dynamic behavior of chiral racemic organoantimony and -bismuth compounds RR'SbCl, RR'BiCl, and RR'SbM [R = 2-(Me2NCH2)C6H4, R' = CH(Me3Si)2, M = H, Li, Na]

RR'SbCl (1) and RR'BiCl (2) [R = 2-(Me(2)NCH(2))C(6)H(4), R' = CH(Me(3)Si)(2)] form by the reaction of R'ECl(2) (E = Sb, Bi) with RLi. The reaction of 1 with LiAlH(4) and metalation with n-BuLi gives RR'SbH (3) and RR'SbLi.2THF (4) (THF = tetrahydrofuran). Transmetalation of 4 with sodium tert-butoxide in the presence of TMEDA (TMEDA = tetramethylethylenediamine) leads to RR'SbNa.TMEDA (5). Structural analyses by (1)H NMR in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO with a variation of the temperature (1, 2, 4, and 5) and by single-crystal X-ray diffraction (1, 2, 4, and 5) revealed the intramolecular coordination of the pendant Me(2)N group on the pnicogen centers in 1 and 2 and on Li or Na in 4 or 5. The variable-temperature (1)H NMR spectra of the hydride 3 in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO show that the pyramidal configuration on antimony is stable up to 100 degrees C, whereas inversion at the nitrogen is not prevented by internal coordination even at -80 degrees C. The crystals of 1, 2, 4, and 5 consist of discrete molecules with the Sb and Bi atoms in an approximately Psi-trigonal-bipyramidal environment in the cases of 1 and 2 and in a pyramidal environment in the cases of 4 and 5. Crystal data for 1: triclinic, space group Ponemacr;, a = 7.243(4) A, b = 10.373(3) A, c = 15.396(5) A, alpha = 79.88 degrees, beta = 78.27 degrees, gamma = 71.480(10) degrees, V = 1066.2(7) A(3), Z = 2, R = 0.0614. 2: monoclinic, space group P2(1)/n, a = 10.665(2) A, b = 14.241(2) A, c = 14.058(2) A, beta = 90.100(10) degrees, V = 2135.1(6) A(3), Z = 4, R = 0.049. 4: monoclinic, space group P2(1)/n, a = 11.552(2) A, b = 16.518(3) A, c = 15.971(5) A, beta = 96.11(2) degrees, V = 3030.2(12) A(3), Z = 4, R = 0.0595. 5: monoclinic, space group P2(1)/n, a = 9.797(2) A, b = 24.991(5) A, c = 14.348(3) A, beta = 94.98(3) degrees, V = 3499.66(12) A(3), Z = 4, R = 0.0571. The dissociation of the intramolecular N-pnicogen bond and inversion at the nitrogen occurs when solutions of 1 or 2 in C(6)D(6) or C(6)D(5)CD(3) are heated above 25 or 30 degrees C. 1 and 3-5 are stable with respect to inversion of the configuration at the antimony in C(6)D(6), C(6)D(5)CD(3), or (CD(3))(2)SO up to 160 degrees C. Bismuth inversion, probably via the edge mechanism, is observed in solutions of 2 in (CD(3))(2)SO at 45 degrees C but not in C(6)D(5)CD(3) below 125 degrees C.

Synthesis and Structures of Intramolecularly Base-Coordinated Group 15 Aryl Halides

Four group 15 monochlorides of the type EAr(2)Cl [Ar = 2-[(dimethylamino)methyl]phenyl, 2-(Me(2)NCH(2))C(6)H(4) (C(9)H(12)N), E = Sb (4), E = Bi (5); Ar = 8-(dimethylamino)-1-naphthyl, 8-(Me(2)N)C(10)H(6) (C(12)H(12)N), E = Sb (6), E = Bi (7)] have been prepared via the salt elimination reactions of 2 equiv of either 2-(Me(2)NCH(2))C(6)H(4)Li or 8-(Me(2)N)C(10)H(6)Li with ECl(3). Four related group 15 dihalides of the type EArX(2) [Ar = 8-(Me(2)N)C(10)H(6), X = Cl, E = As, (8), E = Sb (9); Ar = 2-(Me(2)NCH(2))C(6)H(4), X = Cl, E = Bi (10); X = I, E = Bi (11)] have been prepared via the salt elimination reactions of equimolar amounts of 8-(Me(2)N)C(10)H(6)Li or 2-(Me(2)NCH(2))C(6)H(4)Li with EX(3). The X-ray crystal structures of 4-6, 8, 9, and 11 are described, and the observed trends in the degree of intramolecular coordination of the nitrogen atoms are consistent with the view that the Lewis acidity of these complexes is associated with the E-X sigma orbitals. Crystal data for 4: triclinic, space group P&onemacr;, a = 9.1483(1) Å, b = 9.4868(1) Å, c = 12.9776(2) Å, alpha = 70.614(8) degrees, beta = 85.738(9) degrees, gamma = 83.094(9) degrees, V = 1054.0(2) Å(3), Z = 2, R = 0.0420. Crystal data for 5: monoclinic, space group P2(1)/c, a = 11.9498(1) Å, b = 11.4695(1) Å, c = 13.9456(8) Å, beta = 104.536(6) degrees, V = 1850.2(3) Å(3), Z = 4, R = 0.0375. Crystal data for 6: monoclinic, space group P2(1)/n, a = 9.4991(8) Å, b = 23.455(4) Å, c = 9.726(1) Å, beta = 100.629(8) degrees, V = 2129.8(4) Å(3), Z = 4, R = 0.0406. Crystal data for 8: orthorhombic, space group P2(1)2(1)2(1), a = 9.713(3) Å, b = 9.835(4) Å, c = 13.310(3) Å, V = 1273.8(5) Å(3), Z = 4, R = 0.0695. Crystal data for 9: orthorhombic, space group P2(1)2(1)2(1), a = 9.7140(3) Å, b = 10.0196(1) Å, c = 13.444(3) Å, V = 1308.5(3) Å(3), Z = 4, R = 0.0320. Crystal data for 11: monoclinic, space group P2(1)/c, a = 7.9455(7) Å, b = 19.3949(3) Å, c = 8.6226(9) Å, beta = 93.338(9) degrees, V = 1326.5(2) Å(3), Z = 4, R = 0.0379.