Tetra-p-tolyl-verbindungen p-Tol4Si und p-Tol4Ge: Ein beitrag zur konfiguration der tetraaryl-methan-analoga Ar4M (M = C, Si, Ge, Sn, Pb)

Synthesis and X-ray Crystal Structures of New Tetrahedral Arylethynyl Substituted Silanes

“…4a) and is defined by the fourfold mirror axis (S 4 shape). The slightly distorted tetrahedral angles around the central silicon atom of compound 5 [108.8(1), 109.8(1)°] are characteristic for tetraarylmethane analogues Ar 4 M with M=Si, Ge, Sn, Pb [28][29][30]. Another obvious feature of 5 is the torsion of the aryl groups.…”

Central‐Atom Size Effects on the Methyl Torsions of Group XIV Tetratolyls

“…Because the tolyl groups are chemically similar throughout the series, the dominant effect is simply that of molecular size, which is dictated by the central atom. The smallest analogue, tetratolylmethane, C(C 6 H 4 CH 3 ) 4 (CTol 4 ) is, in fact, isostructural with the largest two of the series,4, 5 the stannane and plumbane analogues (all in space group I $\bar 4$ ), with the silane and germane species lying in the lower‐symmetry space group Pc 6 (Figure 1; CCDC references for all species are: CTol 4 : 712743, SiTol 4 : SUCZIZ, GeTol 4 : SUCZOF, SnTol 4 : PTOLSN, PbTol 4 : SOMMEM). The rationale behind this rather bizarre behavior is believed to lie in the contact interactions of the methyl groups on neighboring molecules.…”

Solid‐State 73Ge NMR Spectroscopy of Simple Organogermanes

“…Specifically, we have investigated the 73 Ge SSNMR spectra of tetraarylgermanes; including Ge( p ‐Me‐C 6 H 4 ) 4 ( 1 ), Ge( p ‐MeO‐C 6 H 4 ) 4 ( 2 ); and GePh 4 ( 3 ). Whereas GePh 4 exhibits a very small, but non‐zero electric field gradient (EFG), due to an approximately spherically symmetrical Ge environment, Ge( p ‐Me‐C 6 H 4 ) 4 16 exhibits a range of bond lengths and angles, which offers the potential to examine the sensitivity of quadrupolar and CSA parameters to small variations in structure. We also examined three other tetra‐substituted germanes: tetrabenzylgermane7 ( 4 ), tetra( tert ‐butoxy)germane ( 5 ), and tetrakis(trimethylsilyl)germane ( 6 ).…”