Compounds of Group 14 Elements with an Element–Element (E = Si, Ge, Sn) Bond: Effect of the Nature of the Element Atom

Abstract

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.

Aryl Oligogermanes as Ligands for Transition Metal Complexes

“…In contrast with the free molecular oligogermanes,, all complexes showed a total absence of luminescence both in solution and in solid form. The presence of transition metal fragments, M(CO) 3 (M = Cr, Mo, W), within the complexes results in a quenching of the emissive properties.…”

“…A comparison between the structural parameters of complexes 3c , 4a , 5a , and those of the parent oligogermanes 3 , 4 , and 5 , respectively (Table ), shows minimal differences, indicating a strong mutual influence of the Ge2, aryl and M(CO) 3 fragments in the molecule, where the acceptor properties of M(CO) 3 are counterbalanced by a Ge2 donation.…”

“…Furthermore, these data indicate that the orbitals of Cr(CO) 3 are located on the HOMO of the whole molecule. The parent digermane 4 is oxidized irreversibly at a much higher potential E ox 1.65 V vs. Ag/AgCl (1.20 V vs. Fc/Fc + ).…”

Aryl Germanes as Ligands for Transition Polymetallic Complexes: Synthesis, Structure, and Properties

“…Furthermore, the similarity in electrochemical behaviours between the mono‐ and digermanium derivatives 4a and 5a indicates that the irreversibility of the oxidation for the catenated Ge complex is not due to the oxidation, and rupture, of the Ge‐Ge bond which is observed for the majority of catenated germanes , …”

Crystal structure of (tert-butyldimethylsilyl)triphenylgermane, Ph3Ge-SiMe2(t-Bu)

“…As apart of our studies of the chemistry of oligogermanium compounds (Zaitsev et al 2012(Zaitsev et al , 2013(Zaitsev et al , 2014a, the title compound was obtained and studied. For related crystal structures of silagermanes, see: Zaitsev et al (2015). The 6PE interactions are intensively discussed in Scudder & Dance (2000); Steiner (2000); Churakov et al (2005 Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT; program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al, 2009); software used to prepare material for publication: OLEX2.…”