Heavier congeners of CO and CO₂ as ligands: from zero-valent germanium (‘germylone’) to isolable monomeric GeX and GeX₂ complexes (X = S, Se, Te)

Abstract

The first isolable germanium chalcogenide complexes 2–5 representing heavier congeners of CO and CO2 were synthesised from the germylone adduct 1.

Taming Silicon Congeners of CO and CO2: Synthesis of Monomeric SiII and SiIV Chalcogenide Complexes

“…published the first PbSe complex in the form of {[K(18‐crown‐6)][K(en) 2 ]K[Rh 3 (CN) 2 (PPh 3 ) 4 (μ 3 ‐Se) 2 (μ‐PbSe)]} 2 ⋅3en (en=ethane‐1,2‐diamine) (Scheme , B ) with the Pb II atom coordinated to the Rh atoms and the selenide atom coordinating to several potassium cations . In the meantime, starting from a chelating bis‐NHC ligand (bis‐NHC=H 2 C[{−NC(H)=C(H)N(Dipp)}C:] 2 , Dipp=2,6‐iPr 2 C 6 H 3 ) supported germanium(0) complex (“germylone”) (bis‐NHC)Ge, we succeeded in synthesizing Ge II chalcogenide (GeX) complexes (X=Se, Te) in which the GeX molecules are push–pull supported by a bis‐NHC donor ligand and the GaCl 3 acceptor (Scheme , C ), respectively . To the best of our knowledge, isolable monomeric silicon(II) chalcogenides with a terminal chalcogen atom X are unknown.…”

A Bis(silylenyl)pyridine Zero‐Valent Germanium Complex and Its Remarkable Reactivity

“…[14] TheS i1ÀN1 distance of 2.1038 (19) )i sl onger than those of Si1ÀN4 and Si1ÀN5 as well as the Si À Nd istance in para-dimethylaminopyridine (DMAP) stabilized NHSi, [15] but comparable to the values reported for five-coordinate Si II complexes. [14] TheS i2-Ge1-Si1 angle of 95.66(2)8 8 is larger than the C-Ge-C angle in germylone B stabilized by ab is(NHC) ligand (86.6(1)8 8), [2b] but smaller than those of cAAC-stabilized germylones A [4d] TheGecenter adopts atrigonal-pyramidal geometry (the sum of the angles around the Ge atom is 322.598 8), which is similar to those in bis(NHC) germylone!GaCl 3 complexes, [16] but different from the situation of coplanar Ge centers in germylone mesoionic germylene metal complexes. [17] TheI Rs tretching vibrations of CO in [SiNSi]GeFe appear at 1969, 1886, 1865, and 1830 cm À1 , which are red-shifted compared to those of the amino-(imino)germylene iron carbonyl complex (2039,1965, and 1930 cm À1 ), indicating that the CO ligands act as strong electron acceptors at the Fe center.…”

Tetrylones: An Intriguing Class of Monoatomic Zero‐valent Group 14 Compounds

“…Two different Si−Se bond lengths were observed in the solid state structure (Si(1)−Se(2): 2.241(6) Å; Si(1)−Se(1): 2.129(2) Å). Germanium analogues of 34 and 35 have also been reported in the meantime …”

“…Germanium analogues of 34 and 35 have also been reported in the meantime. [37] To synthesize the heavier chalcogenide complexes of tetrylone, the reaction of silylone!GaCl 3 adduct 31 with elemental tellurium has been attempted. [36] However,e lemental tellurium does not react with 31 in acetonitrile and the proceeds very slowly in THF.I nc ontrast, treatment of silylone!GaCl 3 adduct 31 with Te=P(nBu) 3 ,w hich is am ild tellurium-transfer reagent, in THF afforded orange crystals of the monomeric bis(NHC)-SiTe 2 complex 36 in 63 %y ield (Scheme 11), together with [Cl 3 GaP(nBu) 3 ], whichw as confirmed by NMR spectroscopy.…”