62120-68-7Relevant academic research and scientific papers
Selective synthesis of tetraarylgermanes and triarylgermanium halides
Wolf, Melanie,Falk, Astrid,Flock, Michaela,Torvisco, Ana,Uhlig, Frank
, p. 143 - 149 (2017/09/29)
A series of novel and previously published tetraarylgermanes aryl4Ge (aryl = m-tolyl, 3,4-xylyl, 3,5-xylyl, 2-naphthyl) and triarylgermanium halides aryl3GeX (aryl = o-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 1-naphthyl, 2,4,6-mesityl, X = Cl, Br) were synthesized and characterized. All solids were investigated using single crystal X-ray diffractometry in order to elucidate the molecular structures. Effects of the substitution pattern of the aryl residue employed have been studied in terms of the impact on the product formation.
The allyl leaving group approach to tricoordinate silyl, germyl, and stannyl cations
Lambert, Joseph B.,Zhao, Yan,Wu, Hongwei,Tse, Winston C.,Kuhlmann, Barbara
, p. 5001 - 5008 (2007/10/03)
A group 14 atom bonded to three mesityl groups (2,4,6-trimethylphenyl) and to one allyl group serves as a novel precursor to tricoordinate group 14 cations, the analogues of the carbocation. The double bond of the allyl group provides an accessible reaction site that is located beyond the ortho methyl groups. Reaction of various electrophiles with the double bond releases the allyl group and leads to formation of the group 14 cations. The mesityl groups then are of sufficient steric bulk to protect the tricoordinate metal center from attack by nucleophiles. This approach is used herein with silicon, germanium, and tin as the central atom. The 29Si chemical shift (δ 225) indicates full cationic character for the silicon system. The 119Sn chemical shift (δ 806) indicates less than full cationic character for the tin system. The positive charge for the germanium system has been assessed by examination of the aromatic 13C chemical shifts. These results provide the highest current cationic character for silylium and stannylium ions.
Etude du transfert monoelectronique entre des germylanions et des piegeurs de spin dia et paramagnetiques
Riviere, P.,Castel, A.,Desor, D.,Abdennadher, C.
, p. 51 - 60 (2007/10/02)
Reactions between organogermyllithium R3GeLi and several substrates favoring SET reactions (3,5-di-t-butyl-orthoquinone, fluorenone, tetracyanoquinodimethane, 2,4,6-tri-t-butylnitrosobenzene, etc.) lead mainly to the formation of digermanes and O- or N-germyl adducts.All these reactions seem to proceed principally by single-electron transfer.An ESR study of the reaction shows transient organic radical anion formation and germanium-centred radicals R3Ge.The prepondancy of this mechanism can be demonstrated by the reaction between R3GeLi and a paramagnetic quinonic species, the galvinoxyl radical: the latter is almost completely transformed into a diamagnetic anion.Digermanes mainly produced in these reactions are formed via radicalar duplication as well as lithiogermolysis of reaction adducts.
Synthesis, reactivity and crystal structure of trimesitylgermylamine, Mes3GeNH2
Riviere-Baudet, Monique,Morere, Alain,Britten, James F.,Onyszchuk, Mario
, p. C5 - C8 (2007/10/02)
Trimesitylgermylamine, Mes3GeNH2, prepared in high yield by the coupling of Mes3GeCl (Mes = 2,4,6-Me3C6H2) with NaNH2 or LiNH2, has been fully characterized by 1H and 13C NMR, IR and mass spectrometry.It is a rare example of a stable primary germylamine, melting at 166 deg C, which is only slowly cleaved by H2O, CH3OH, HCl or phenol, indicating tht the central Ge atom is protected from attack by the mesityl groups.Unlike other germylamines, Mes3GeNH2 reacts with tBuCOCl to give the N-substituted amide, Mes3GeNHCOtBu, rather than Mes3GeCl.Preliminary X-ray crystallographic analyses reveal that the Ge atom has approximate tetrahedral coordination with an average Ge-C bond length of 1.978(3) Angstroem and a Ge-N bond length of 1.854(3) Angstroem, and crowding around the Ge atom so that it is shielded from attack by approaching reactants.
TRIMESITYLGERMYLAMINE Mes3GeNH2: SYNTHESES, STRUCTURE, PROPRIETES
Riviere-Baudet, Monique,Morere, Alain,Onyszchuk, Mario,Satge, Jacques
, p. 75 - 90 (2007/10/02)
Sterically hindered trimesitylgermylamine is a rare example of a stable primary germylamine.X-ray structural data show that germanium is shielded from nucleophilic attack by the surrounding mesityl groups.Nitrogen is still accessible, and the only reactions which occur are those in which the first step of the transition state proceeds through an electrophilic attack on nitrogen.With acid chlorides, Mes3GeNH2 reacts mainly as a primary amine forming the corresponding N-germylamides.The primary amine behaviour is also evident in the reaction with aldehydes.However, functional hydrogen cannot be substituted by lithium, probably because of steric hindrance which prevents the approach of an organolithium derivative.Insertion reactions into the Ge-N bond are difficult.Carbon dioxide and disulfide react only upon heating and yield trimesitylgermyliso- or isothiocyanates (Mes3GeN=C=X; X = O, S) through thermal degradation of the carbamate or dithiocarbamate initially formed. 3,5-di-tert-butylorthoquinone does not form an adduct with Mes3GeNH2, but is slowly transformed into 3,5-di-tert-butylorthocatechol.In spite of its steric hindrance, the trimesitylgermylamino group failed to stabilize a N-germylated germa-imine since the precursor Mes3Ge(Cl)NH-GeMes3 is not stable and gave cyclodigermazane (Mes2GeNH)2 and trimesitylgermyl chloride through Ge-Cl/Ge-N exchange reactions. Key words: Trimesitylgermylamine; 4-methyl 1-trimesitylgermoxy-benzene; N-trimesitylgermyl 2,2-dimethylpropanamide; trimesitylgermylisocyanate; trimesitylgermylisothiocyanate; tetramesitylcyclodigermazane.
Trimesitylgermyllithium: synthese et reactivite
Castel, A.,Riviere, P.,Satge, J.,Ko, Y.H.,Desor, D.
, p. 7 - 15 (2007/10/02)
The new organogermyllithium Mes3GeLi has been prepared in good yield by hydrogermolysis reaction of t-butyllithium in THF.The bulky group favours stabilization in the form of the THF complex.Mes3GeLi has been characterized by alkylation reaction with MeI.
TRIARYL-SILYL, -GERMYL, AND -STANNYL RADICALS MAr3 (M=Si, Ge, OR Sn AND Ar=2,4,6-Me3C6H2) AND Ge(2,6-Me2C6H3)3: SYNTHESIS AND ESR STUDIES
Gynane, Michael J. S.,Lappert, Michael F.,Riley, Paul I.,Riviere, Pierre,Riviere-Baudet, Monique
, p. 5 - 12 (2007/10/02)
The triarylmetal-centred radicals MAr3 (M=Si, Ge, or Sn: Ar=2,6-Me2C6H3 or 2,4,6-Me3C6H2) have been prepared from the appropriate triarylmetal chloride, MAr3Cl, and an electron-rich olefin >2 (R=Me or Et) under UV irradiation in toluene at low
