Anastasia A. Selina

Synthesis and characterization of 3- and 4-phenylgermatranes: X-ray crystal structures of N(CH2CH2O)2(CH2CHPhO)GeZ (Z=F, OSiMe3, CCPh) and N(CH2CH2O)2(CHPhCH2O)GeOH

Abstract Reaction of excess of product A [(HOCH2CH2)2NCH2CH(Ph)OH (1):(HOCH2CH2)2NCH(Ph)CH2OH (2)=9:1] with GeCl4 led to a mixture of 1-chloro-3-phenylgermatrane (3) and 1-chloro-4-phenylgermatrane (4). Compound 4 was isolated in yield 9% from this mixture. Reaction of (EtO)3GeCl with product A gave 3 in yield 55%. 1-(Phenylethynyl)-3-phenylgermatrane (5) was prepared in yield 31% by treatment of (EtO)3GeCCPh with product A. Reaction of product A with mixture of GeO2 and H2O produced N(CH2CH2O)2(CH2CHPhO)GeOH (6) in yield 73%. The presence of N(CH2CH2O)2(CHPhCH2O)GeOH (7) among the products of this reaction was confirmed by 1H-, 13C-NMR spectroscopy and X-ray analysis. N(CH2CH2O)2(CH2CHPhO)GeF (8) is formed by the treatment of 6 with BF3·Et2O. N(CH2CH2O)2(CH2CHPhO)GeOSiMe3 (9) was obtained by silylation of 6 with (Me3Si)2NH or Me3SiCl–Et3N. Refluxing of a suspension of 6 in xylene with continuous removal of water by azeotropic distillation afforded [N(CH2CH2O)2(CH2CHPhO)Ge]2O (10). 9 reacted with SOCl2, Me3SiBr and Me3SiOTf to give N(CH2CH2O)2(CH2CHPhO)GeX (3, X=Cl; 11, X=Br; 12, X=OTf), respectively. Reaction of 11 with Et3SnOMe led to the formation of N(CH2CH2O)2(CH2CHPhO)GeOMe (13). Germatranes N(CH2CH2O)2(CH2CHPhO)GeY [14, Y=Flu (fluorenyl); 15, Y=N(SiMe3)2] were obtained from the nucleophilic substitution of the substituent X in N(CH2CH2O)2(CH2CHPhO)GeX (X=OSiMe3, Br) with the corresponding LiY. All compounds were characterized by 1H- and 13C-NMR spectroscopy and mass spectrometry. Single-crystal structures of 5 and 7–9 were determined by X-ray diffraction studies.

Tetrakis­(phenyl­ethynyl)­germanium(IV)

The title compound, (PhC≡C)4Ge or [Ge(C8H5)4], crystallizes in the space group I\overline 4 with \overline 4 molecular symmetry. The coordination polyhedron of the central atom is a slightly distorted tetrahedron, with C—Ge—C angles in the range 107.95 (17)–110.24 (9)°.

Synthesis and crystal structure of the germatrane E-N(CH)2CH2O3GeC(Br)=C(Br)Ph

The reaction of (phenylacetylenyl)triethoxygermane, (EtO)3GeC≡CPh (3), with bromine in CHCl3/CCl4 solution leads to a mixture of Z- and E- (EtO)3GeC(Br)=C(Br)Ph (4) in the ratio Z/E = 3/1. Treatment of this product with N(CH2CH2OH)3 affords a mixture of Z- and EN(CH2CH2O)3GeC(Br)=C(Br)Ph (2) in high yield. Compound E-2 was isolated in 16% yield. The molecular composition and the structure of all new compounds have been established by elemental analyses, 1H and 13C NMR spectroscopy. The crystal structure of E-2 is reported. The possible reasons for the different Z/E ratios in the products of the bromination of 3 and N(CH2CH2O)3GeC≡CPh (1) are discussed using DFT calculations.

Synthesis and characterization of N-methyl-substituted germocanes. Crystal structure of MeN(CH2CH2O)2GeBr2

The reaction of GeHal4 with MeN(CH2CH2OSiMe3)2 affords dihalogermocanes MeN(CH2 CH2O)2GeHal2 (1, Hal = Br; 2, Hal = Cl). Treatment of Me2Ge(NMe2)2 with MeN(CH2CH2OH)2 leads to dimethylgermocane MeN(CH2CH2O)2GeMe2 (3). The composition and structure of 1-3 were established by elemental analyses, 1H, 13C NMR spectroscopy, and mass spectrometry. The crystal structure of 1 is reported; structural data obtained from geometry DFT optimization on 1 are in good agreement with experimental results. Values of the electron density in the N→Ge bond critical point and the Laplacian of charge density for 1-3 indicate a closed-shell interaction between the Ge and N atoms.