Donor-acceptor molecular oligogermanes: Novel properties and structural aspects

Abstract

The linear oligogermyl amide 2, Ph3GeGeMe2NMe2, was obtained by reacting Ph3GeLi with 1, Me2Ge(Cl)NMe2. The amide 2 was used for the synthesis of molecular oligogermanes 3, Ph3GeGeMe2Ge(C6F5)3, and 4, [Ph3GeGeMe2]2Ge(C6F5)2, containing electron donor (Me, Ph) and acceptor (C6F5) groups, by using a hydrogermolysis reaction in n-hexane. The molecular structures of 3 and 4 were studied by XRD. It was shown that, in its crystal form, 3 forms wide channels, in which the solvated nonpolar n-hexane molecule is present. The NMR (1 H, 13 C and 19 F), optical (UV/vis absorption, luminescence) and electrochemical (cyclic voltammetry) properties of both compounds were also studied. The impact of the substitution type (at the end of the compound, such as in 3, or within the compound, such as in 5, on the physical properties was also studied.

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

“…This observation is in good agreement with our previous results. [2d], A comparison between the mono‐ and dichromium derivatives reveals that inserting additional electron‐withdrawing groups, such as Cr(CO) 3 , also resulted in a decrease of the IR vibrational bands due to an increase of the donor abilities owing to the conjugation (σ‐ and π‐fragments) between all fragments of the molecule (Ge‐Ge, arene, Cr(CO) 3 ).…”

Structural Motifs in Aryl Organogermanium Ge-O Derivatives for Material Design

“…The presence of organic substituents at peripheral Ge atoms in compound 4 enables the formation of chiral monocrystals that are suitable to undergo XRD analysis. It is known that germanium zeolites [66] and molecular Ge compounds [67] of similar structures may be used for the sorption of hydrocarbons. Special interest will be paid to the organogermanium compounds, including these and other (absorption/emission optical [68] and semiconducting [69]) properties caused by the different types of conjugation (σ-, π-, and d-) [70] between the structural blocks, which stimulates in future novel research on germanium-heteroatom derivatives.…”

Oligoorganogermanes: Interplay between Aryl and Trimethylsilyl Substituents

“…As typical examples, we choose Ar 3 Ge-Ge(SiMe 3 ) 3 (Ar = p -C 6 H 4 Me ( 1 ), p -C 6 H 4 F ( 2 ), C 6 F 5 ( 3 )), where the electronic properties of aryl groups change from donating to accepting ( 1 and 2 vs. 3 ). Interestingly, based on the electron-donating SiMe 3 (electronegativity for Ge, 1.99–2.02; Si, 1.74–1.91) [ 28 ] and electron-withdrawing p -C 6 H 4 F, C 6 F 5 properties of the substituents in 2 and 3 , both these compounds can be called donor–acceptor compounds [ 21 , 29 ].…”