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

Introducing Stereogenic Centers to Group XIV Metallatranes

The syntheses of the novel amino alcohols NH(CH₂CMe₂OH)₂(CMe₂CH₂OH) (1) and N(CH₂CMe₂OH)(CMe₂CH₂OH)(CH₂CH₂OH) (2) as well as the stannatranes N(CH₂CMe₂O)(CMe₂CH₂O)(CH₂CH₂O)SnX (3, X = Ot-Bu), N(CH₂CMe₂O)₃SnOC(O)C₉H₁₃O₂, 4, and germatranes N(CH₂CMe₂O)(CMe₂CH₂O)(CH₂CH₂O)GeX (5, X = OEt; 6, X = Br) are reported. The compounds were characterized by ¹H, ¹³C (1-6), ¹¹⁹Sn (3, 4), and ¹⁵N (2, 3, 5) NMR and IR spectroscopy, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analysis. Graphset analyses were performed for compounds 1 and 2. Detailed NMR spectroscopic studies including variable temperature ¹H (3, 5, 6) and ¹¹⁹Sn (3, 4) DOSY experiments reveal the stannatrane 3 being involved in a monomer-dimer equilibrium. Both the stannatranes 3 and 4 as well as the germatranes 5 and 6 show Λ ⇌ Δ isomerization of the atrane cages in solution.

Synthesis, X-ray Diffraction Studies, and DFT Calculations on Hexacoordinated Germanium Derivatives: The Case of Germaspirobis(ocanes)

Synthesis of the title compounds, viz. [RN(CH2CHR'O)2]2Ge (1, R = Me, R' = H; 2, R = Me, R' = Ph; 3, R = Ph, R' = H), by the reaction of 2 equiv of corresponding dialkanolamines RN(CH2CHR'OH)2 (4, R = Me, R' = H; 5, R = Me, R' = Ph; 6, R = Ph, R' = H) with (AlkO)4Ge is reported. Composition and structures of all novel compounds were established by 1H and 13C NMR spectroscopy and mass spectrometry as well as elemental analysis data. The single-crystal X-ray diffraction of 2 has clearly indicated the presence of two transannular interactions Ge<--N in the compound. N atoms are cis-orientated. The compound 3 possesses long Ge...N distances. The structural data obtained from geometry optimizations by DFT calculations on 1-3 reproduces experimental results. Both cis- and trans-isomers were studied, and cis-configuration was found to be more thermodynamically stable for all three compounds. The transition states for possible cis <--> trans rearrangement processes in 1-3 were calculated. The properties of the Ge-O and Ge<--N bonds in 1-3 were analyzed by the AIM approach. The interactions between the Ge atom and N atoms as well as O atoms possess predominantly ionic character.