A series of oligogermanes, (Me 3 Si) 3 GeGeCl 3 , (C 6 F 5 ) 3 GeGePh 3 , (C 6 F 5 ) 3 GeGe(p-Tol) 3 , and (C 6 F 5 ) 2 Ge[Ge(p-Tol) 3 ] 2 , containing substituents with different electronic properties at neighboring germanium atoms were synthesized. According to X-ray diffraction studies, UV/visible spectroscopy, and quantum chemical calculations, these "donor−acceptor" oligogermanes are characterized by energies of electronic transitions lower than those for other similar compounds.

From the viewpoint of the fixation of atmospheric nitrogen, there is a long-term general interest in the identification and characterization of compounds that result from the reaction of transition metals with dinitrogen. In addition, the investigation of the interaction of N 2 with transition-metal compounds has intrinsic significance because of the isoelectronic, isolobal nature of dinitrogen and carbon monoxide. There is a voluminous amount of literature [1] on transition-metal carbonyl compounds, from which it is concluded that the nature of the generally strong bonding interaction of CO with the transition-metal center in such compounds is well-understood.Recently, a series of simple linear transition-metal carbonyl complexes of the type OCÀMÀX (M = Cu, [2] Ag, [3] or Au [4] ; X = F, Cl, or Br) were thoroughly investigated in the gas phase by means of their rotational spectra to give details of their geometry and electronic structure. Information about the electric-charge redistribution at the metal center is contained in the nuclear quadrupole coupling constants for M = Cu or Au. The interaction between CO and M was also found to be strong in these transient species. On the other hand, the hydrogen-bonded species OC···H À X, which may be envisaged, formally at least, as generated from OC À M À X by replacement of M by H, have been investigated extensively by rotational spectroscopy. [5][6][7] Such complexes are weakly bound (here depicted with ···) with intermolecular binding energies of only a few kJ mol À1 . The dinitrogen complexes N 2 ···HÀX have linear geometries similar to those of OC···H À X, but with slightly weaker hydrogen bonds. [8][9][10] The isostructural nature of OC···H À X and N 2 ···H À X can be understood by assuming that the electrophilic region of HX seeks the most nucleophilic region of CO or N 2 (namely, the axis of a nonbonding

Two series of germanium compounds, (pTol) 3 Ge-MMe 3 (M = Si (1), Ge (2), Sn (3)) and (Me 3 Si) 3 Ge-MPh 3 (M = Ge (4), Sn (5)), were prepared using lithium or potassium intermediates. The changing of the reaction conditions results in trigermane Ph 3 Ge-Ge(SiMe 3 ) 2 -GePh 3 (6). The molecular structures of 1, 2, and 6 were investigated by X-ray analysis. By UV/visible spectroscopy it is established that introduction of a tin atom results in a significant bathochromic absorption shift. Furthermore, according to cyclic voltammetry, oxidation potentials decrease in the order 1 > 2 > 3. The electronic structures of 1−4 and related (Me 3 Si) 3 GeSiPh 3 were investigated by DFT calculations. Fluorescence properties of 1−3 were studied in the solid state and in solution; for compound 3 phosphorescence (lifetime is 4.58 ms) is observed in the solid state.