Baosheng Lee

Facile cleavage of C-H bonds. Reaction of trimethylaluminum with bis(diphenylphosphinoyl)methane. Synthesis and molecular structure of [Al(CH3)][(C6H5)2P(O)CP(O)(C6H5)2]2[Al(CH3)2]2.

cm3/mol (from the bulk density of water) and 12 cm3/mol (from the ionic radius of Cs’ of 0.169 nm given by Pauling19), so at first glance it seems that expulsion of 1 mol of Cs’ should allow for accommodation of only 0.67 mol of H20. Thus, either the effective volume of Cs+ within the lattice is considerably larger than its ionic radius would indicate, or the effective volume of a water molecule within the lattice is considerably smaller than it is in bulk water or some combination of the two. Since it is unreasonable to postulate a water density within the lattice which is greater (by a factor of nearly 5!) than the bulk value to account for the discrepancy, we attribute the majority of the effect to a much larger effective volume for Cs+. Geometric arguments based on the sizes of Cs+ and H 2 0 in relation to the size of the octahedral cavity10*20-22 can be made which are in agreement with this conclusion. Briefly, even though the Cs’ cation does not completely fill the cubic cavity (which is 0.5 nm on a side10*2*22), it is just large enough to preclude the presence of water molecules. Thus, void space is left within the cavity which does not have the proper geometry to accommodate the incorporation of interstitial water. A more detailed description of this “discreteness of size” effect will be reported in a future contribution, along with a discussion of the insight provided by such measurements of solvent transport ito the remarkable sensitivity of the formal potential of these nickel ferrocyanide films to the identity of the presence of various alkali metal cations.

Reactions of 2-aminobiphenyl with group 13 metal alkyls. Syntheses and molecular structures of [Me2MN(H)Bp]2 (M = Al, Ga) and [(i-Bu)2AlN(H)Bp]2 (NH2 Bp = 2-aminobiphenyl)

Abstract Reaction of Me 3 M (M = Al, Ga) with 2-aminobiphenyl, NH 2 Bp, in toluene affords aluminium ( I ) and gallium ( II ) crystalline complexes of the type [Me 2 MN(H)Bp] 2 . Compound I crystallizes in the triclinic space group P 1 (No. 2) with unit-cell parameters a = 9.046(1), b = 9.767(1), c = 17.713(2) A, α = 78.30(1)°, β = 75.44(1)°, γ = 63.01(1)°, V = 1342.5(3) A 3 , and D c = 1.12 g cm −3 for Z = 2. Full-matrix least-squares refinement based on 2644 observed reflections with intensities in the range 3.50 R = 0.054 ( R w = 0.069). The crystalline product [( i -Bu) 2 AlN(H)Bp] 2 ( III ), isolated from reaction of diisobutylaluminium hydride with 2-aminobiphenyl in toluene, crystallizes in the monoclinic space group P 2 1 / n with unit-cell parameters a = 12.835(3), b = 22.306(11), c = 13.545(3) A, β = 93.00(2)°, V = 3873(2) A 3 and D c = 1.06 g cm −3 for Z = 4. Full-matrix least-squares refinement based on 1935 observed reflections with intensities in the range 3.50 R = 0.089 ( R w = 0.099). Compound I resides in a trans conformation relative to aza hydrogen atoms while a cis conformation is observed for III .

Group 13 chemistry of sterically hindered amines. Synthesis and molecular structure of [Me2M-Ada]2 (M Al, Ga; Ada 1-aminoadamantane) and [(i-Bu)Al-iminodibenzyl]2

Reaction of Me3M (M  Al, Ga) with 1-aminoadamantane, Ada, in toluene affords crystalline complexes of the type [Me2M-Ada]2. The gallium compound, I, isomorphous with the aluminum compound, II, crystallizes in the triclinic space group P with unit cell parameters a=6.728(1), b=9.957(2), c=10.341(2) A, α=74.30(1), β=73.94(1), γ=72.19(1)°, V=620.6(2) A3 and Dcalc=1.34 g cm−3 for Z=1. Least-squares refinement based on 1794 observed reflections (I>3σ(I)) converged at R=0.059, Rw=0.080. I resides about a crystallographic center of symmetry and contains a planar Ga2N2 four-membered ring. The Ga2N2 ring has a mean GaN bond distance of 2.030(9) A. The mean GaC bond distance in the dimethylgallium unit is 1.974(9) A. The crystalline product [(i-Bu)Al-iminodibenzyl]2 (III), isolated from reaction of diisobutylaluminum hydride with iminodibenzyl, (C14H12)NH, in toluene, crystallizes in the triclinic space group P with unit cell parameters a=10.767(2), b=12.264(3), c=13.230(4) A, α=75.57(2), β=74.14(2), γ=73.58(2)°, V=1583.7(7) A3 and Dcalc=1.16 g cm−3 for Z=2. Least-squares refinement based on 2216 observed reflections (I>3σ(I)) converged at R=0.093, Rw=0.118. Compound III results from a unique condensation reaction in which ortho-metallation of one of the aromatic rings of iminodibenzyl was observed. Compound III has a mean AlN bond distance of 2.036(7) A. The mean AlCisobutyl bond distance of 1.98(3) A is comparable to 1.954(8) A for the AlCaromatic fragment.

Organogallium chemistry of macrocyclic amines. Synthesis and molecular structure of [Ga(CH3)3]4[(CH3)4[14]aneN4] and [Ga(CH3]2[14]aneN4[Ga(CH3)3]2

Reaction of trimethylgallium with the tetradentate macrocyclic amine [(CH3)4[14]aneN4] in toluene affords the crystalline adduct product [Ga(CH3)3]4-[(CH3)4[14]aneN4], I. I crystallizes in the orthorhombic space group Pbca (No. 61) with unit cell parameters a = 14.002(2), b = 18.542(3), c = 14.477(3) A, V = 3758.6 A3, and Dcalc = 1.26 g cm−3 for Z = 4. Full-matrix least-squares refinement based upon 2222 observed reflections converged at R = 0.039 (Rw = 0.060). Due to the four trimethylgallium units the macrocycle in I has been forced to assume an exodentate conformation. I resides about a crystallographic center of symmetry with independent GaN bond distances of 2.182(4) and 2.202(4) A. The crystalline product [Ga(CH3)]2[14]aneN4[Ga(CH3)3]2, II, isolated from reaction of trimethyl-gallium with [14]aneN4 in toluene, crystallizes in the triclinic space group P1 (No. 2) with unit cell parameters a = 8.016(4), b = 9.437(3), c = 9.669(3) A, α = 75.53(3), β = 67.80(4), γ = 73.26(4)°, V = 640.2 A3, and Dcalc = 1.54 g cm−3 for Z = 1. Full-matrix least-squares refinement based upon 1694 observed reflections converged at R = 0.042 (Rw = 0.059). II resides about a crystallographic center of symmetry with a planar Ga2N2 four-membered ring occupying the central cavity of the macrocycle. The Ga2N2 ring has a mean GaN bond distance of 2.009(6) A. The GaNGa bond angle in the Ga2N2 ring is 90.2(2)° while the NGaN bond angle is 89.8(2)°. The ··· Ga contact of 2.847(1) A does not suggest significant metal-metal interaction. The GaN distances in I and II are among the longest reported.

Reaction of organoaluminium species with bidentate phosphine ligands. Synthesis and molecular structure of [AlCl3][(Ph2P)2CH2][AlCl2(CH3)] and [AlCl3]2[(Ph2P(O))2CH2]

Reaction of methylaluminium sesquichloride with bis(diphenylphosphino) methane and bis(diphenylphosphinoyl)methane affords [AlCl3][(Ph2P)2CH2][AlCl2(CH3)] (I) and [AlCl3]2[(Ph2P(O))2CH2] (II), respectively. Compound I crystallizes in the triclinic space group P−1 with unit cell parameters a = 10.009(3), b = 10.748(4), c = 14.806(5) A, α = 90.38(3), β = 103.36(2), γ = 96.89(3)°, V = 1537.5 A3 and ϱ = 1.36 for Z = 2. Compound II crystallizes in the monoclinic space group C2 with unit cell parameters a = 12.773(2), b = 13.028(3), c = 9.461(2) A, β = 104.43(2)°, V = 1524.60 A3 and ϱ = 1.49 for Z = 2. Full-matrix least-squares refinement based on 3034 observed reflections for I converged at R = 0.047 (Rw = 0.066); full-matrix least-squares refinement based on 1565 observed reflections for II converged at R = 0.043 (Rw = 0.050). Both products result from reaction of the disproportionation products of methylaluminium sesquichloride, AlCl3 and AlCl2(CH3).

Reaction of Triethylaluminum with Bis(Diphenylphosphinoyl)Methane. Synthesis and Molecular Structure of [Al(C2H5)][(Ph2P(O))2C]2[Al(C2H5)2]2

Abstract Reaction of triethylaluminum with bis(diphenylphosphinoyl)methane in toluene/heptane affords the crystalline condensation product [Al(C2H5)][(Ph2P(O))2C]2[Al(C2H5)2]2. The title compound crystallizes in the monoclinic space group C2/c with unit cell parameters a = 26.157(9), b= 10.261(3), c = 24.607(9) A, β = 120.48(2)[ddot], V = 5691.65 A3 and ρ = 1.23 g cm−3 for Z = 4. Full-matrix least-squares refinement based on 2778 observed reflections converged at R = 0.051, R w = 0.068. During the course of the reaction both of the central methylene C-H bonds of each ligand were cleaved, along with four Al-Et bonds, thereby eliminating four units of ethane, and resulting in a five-coordinate aluminum atom residing in a trigonal bipyramidal environment at the core of the molecule.

Organoaluminum-Thiacrown Ether Chemistry. Synthesis and Molecular Structure of [Al(CH3)3]4[12]aneS4: An Unusual Example of an Endodentate Conformation of [12]aneS4

Abstract The crystalline organoaluminum macrocyclic ligand complex [Al(CH3)3]4[12]aneS4 was prepared by reaction of the sulfur-based crown ether_ with trimethylaluminum in toluene. The title compound crystallizes in the triclinic space group P1 with unit cell parameters a α 8.548(2), b α 9.949(3), c α 11.225(3)A, α α 64.08(2), β α 78.55(2), γ α 86.96(3)[ddot], V α 840A3, and D c α 1.04gcm-3 for Z α 1. Least-squares refinement based on 1761 observed reflections (I ≥ 3[sgrave](I)) in the range 3.50[ddot] < 20 < 45.0[ddot] converged at R α 0.034, R w α 0.044. The molecule is situated about a crystallographic centre of symmetry with the four sulfur atoms constituting a plane. As evidenced by the independent distances of 2.530(1) A and 2.500(1) A, the A1-S interactions in the organoaluminum complex are rather substantial. Particularly significant is the fact that the conformation of the macrocycle in the title compound is endodentate as the four sulfur atoms are directed towards the interior of the macrocyclic...

Reaction of trimethylaluminium with sulphur derivatives of bis(diphenylphospino)methane and bis(diphenylphosphino)ethane. Synthesis and molecular structure of [Al(CH3)2][(C6H5)2P(S)CHP(S)(C6H5)2][Al(CH3)3] and [Al(CH3)3]2[(C6H5)2P(S)CH2CH2P(S)(C6H5)2]

Abstract Reaction of trimethylaluminium with bis(diphenylthiophosphinoyl)methane and bis(diphenylthiophosphinoyl)ethane affords the crystalline compounds [Al(CH 3 ) 2 ][(C 6 H 5 ) 2 P(S)CHP(S)(C 6 H 5 ) 2 ][Al(CH 3 ) 3 ] ( I ) and [Al(CH 3 ) 3 ] 2 [(C 6 H 5 ) 2 P(S)CH 2 CH 2 P(S)(C 6 H 5 ) 2 ] ( II ), respectively. Compound I crystallizes in the monoclinic space group P 2 1 / n (No. 14) with unit cell parameters a = 18.126(2), b = 9.569(2), c = 19.394(3) A, β = 110.20(1)°, V = 3156.7(7) A 3 , and ϱ = 1.21 g cm −3 for Z = 4. Least-squares refinement based on 2891 observed reflections [ I > 3σ( I )] converged at R = 0.040, R w = 0.051. Compound II crystallizes in the triclinic space group P 1 (No. 2) with unit cell parameters a = 12.076(3), b = 13.148(3), c = 13.114(3) A, α = 98.32(2), β = 100.55(2), γ = 116.41(2)°, V = 1772.1(7) A 3 , and ϱ = 1.14 g cm −3 for Z = 2. Least-squares refinement based on 3012 observed reflections [ I > 3σ( I )] converged at R = 0.049, R w = 0.056. Compound I results from a unique condensation reaction in which one of the central methylene CH bonds was cleaved in addition to one AlCH 3 bond, resulting in an unusual AlPSC four-membered ring. The length of the hydrocarbon chain in bidentate phosphine ligands appears to play an important role in their reactivity with organo-aluminium species, as reaction of bis(diphenylthiophosphinoyl)ethane with trimethylaluminium did not facilitate condensation, but resulted in an addition compound, II . These results demonstrate a comparatively greater acidity of the hydrocarbon chain hydrogen atoms of bis(diphenylthiophosphinoyl)methane relative to bis(diphenylthiophosphinoyl)ethane.

GROUP 13 AMIDES. SYNTHESES AND MOLECULAR STRUCTURES OF [(i-Bu)2Al-N(H)Mes]2,[(i-Bu)Al-N(H)Ph(t-Bu)2-μ-(CMe2CH2)]2, [Me2In-N(H)Ph′]2, AND [(i-Bu)2Al-N(H)Ada]2

Abstract The sterically demanding Group 13 amide dimers [(i-Bu)2Al-N(H)Mes]2 (I), [(i-Bu)Al-N(H)Ph(t-Bu)2-μ-(CMe2CH2)]2 (II), [Me2In-N(H)Ph′]2 (III), and [(i-Bu)2Al-N(H)Ada]2 (IV) (Ada = adamantyl; Bu=butyl; Mes = Ph(Me)3; Ph = phenyl; Ph′= 2-biphenyl) have been prepared by reaction of (i-Bu)2AIH or Me3In with the respective primary amine and characterized by 1H NMR, elemental analyses, and single crystal X-ray diffraction. I crystallizes in the triclinic space group P1 with unit cell parameters a = 9.272(1), b = 9.718(2), c = 11.585(2)A, α = 101.76(1)°, β = 106.69(1)°, γ = 109.70(1)°, V=887.5(2)A3, and Dcalc = 1.03g cm−3 for Z = 1. Least-squares refinement based on 1644 observed reflections with intensities I > 3σ(I) in the range 3.5 < 2 < 45.0° converged at R = 0.043 and R w = 0.054. II crystallizes in the monoclinic space group P21/c with unit cell parameters a = 11.292(5), b = 17.544(9), c = 11.532(5)A, β = 107.99(4)°, V = 2173(2)A3, and Dcalc = 1.05 g cm−3 for Z = 2. Least-squares refinement based on...

Participation of Methylene Chloride in Organo-Group 13 Systems. Synthesis and Molecular Structure of [(C4H9)2Al{N(CH2CH2O)3}Al(Cl)]2 and [(CH3)Ga·[14]aneN4]Cl2

Abstract The organoaluminum complex [(C4H9)2Al{N(CH2CH2O)3}A1(C1)]2, I, was prepared by reaction of an excess of (i-C4H9)2AlH with triethanolamine, N(CH2CH2OH)3. I crystallizes in the triclinic space group P1 with unit cell parameters a = 10.246(4), b = 12.864(4), c= 14.681(6)A, α= 104.96(3), β=89.92(3), γ = 96.84(3)[ddot], V= 1855 A3 and D c = 1.24gcm−3 for Z = 2. Least-squares refinement based on 3745 observed reflections with intensities I>3[sgrave] (I) in the range 3.50 < 20 < 45.0[ddot] converged at R=0.080, R W =0.099. I contains two triethanolamine ligands bridged by four Al fragments. The two core Al atoms are six-coordinate residing in octahedral environments. The mean Al-C distance in I is 1.978(9) A while the Al-O distances range from 1.798(4) to 1.931(5) A. The crystalline product [(CH3)Ga-[14]aneN4]Cl2, II, isolated from reaction of (CH3)3Ga with [14]aneN4, crystallizes in the monoclinic space group P21/c with unit cell parameters a=13.853(5), b=10.755(4), c=13.147(5) A, β=113.80(3)[ddot] V=1...