7301-42-0Relevant articles and documents
Oligothienyl catenated germanes and silanes: Synthesis, structure, and properties
Zaitsev, Kirill V.,Lam, Kevin,Poleshchuk, Oleg Kh.,Kuz'Mina, Lyudmila G.,Churakov, Andrei V.
supporting information, p. 5431 - 5444 (2018/04/23)
The synthesis of two new groups of oligothienyl catenated silanes and germanes, Me5M2Thn (1a-b), Me5M2ThnM2Me5 (2a-c) (terminal), and ThnM2Me4Thn (3a-d) (internal) (M = Si, Ge; n = 2, 3; Th = 2- or 2,5-thienyl), is reported. The study of their structural parameters as well as of their spectral (NMR), electrochemical (CV) and optical (UV/vis absorbance, luminescence) properties has been performed in detail; in addition, the unexpected compound [Th2Si2Me4Th]2 (3a′) is also studied. Theoretical investigations have been performed for model compounds in order to establish structure-property relationships. The molecular structures of 2a (Me5Si2Th2Si2Me5), 2b (Me5Ge2Th2Ge2Me5), 3a (Th2Si2Me4Th2) and 3b (Th2Ge2Me4Th2) have been investigated by X-ray diffraction analysis. An effective conjugation with flattening of both Th planes in terminal 2a and 2b was observed. The main trends in the dependence of the optical and electrochemical properties on the structural parameters have been established. All of the compounds studied exhibit a strong emission within the 378-563 nm range, and the maximal quantum yield (up to 77%) is observed for the Si derivative 3a′. For the majority of the compounds, the quantum yields (20-30%) are significantly larger than for 2,2′-bi- and 2,2′:5′,5′′-terthiophenes. Due to their good emission properties, these compounds could be used to develop new materials with specific spectral properties.
Preferential carbene insertion into Ge-H vs. other heavier group 14 hydrides via samarium carbenoids
Kondo, Hitoshi,Yamanoi, Yoshinori,Nishihara, Hiroshi
, p. 6671 - 6673 (2011/08/02)
The relative reactivities of Zn, Al, and Sm carbenoids in the chemoselective carbene insertion reaction of heavier group 14 hydrides were studied. By variation of the reaction protocols using Sm carbenoids, insertion reaction can favour the Ge-H bonds to give Ge-alkylated derivatives in good to high yield.
Platinum-catalyzed bis-germylation of alkynes with organodigermanes and cyclic oligogermanes
Mochida, Kunio,Wada, Tohru,Suzuki, Kaoru,Hatanaka, Wakako,Nishiyama, Yuriko,Nanjo, Masato,Sekine, Akiko,Ohashi, Yuji,Sakamoto, Masato,Yamamoto, Akio
, p. 123 - 137 (2007/10/03)
Hexamethyldigermane, Me3GeGeMe3, reacted with various alkynes in the presence of platinum complexes at 120 °C to afford Z-1,2-bis(germyl)ethenes in moderate to good yields. Terminal alkynes exhibit higher reactivities than internal ones. [Pt(acac)2] and [Pt(dba)2] serve as efficient catalysts, while [Pt(PPh3)4], [PtCl2(PPh3)2], and [Pt(dba)2]-phosphite were found to be inactive. Four- and six-membered cyclic oligogermanes, such as dodecamethylcyclohexagermane, (Me2Ge)6, reacted with alkynes in the presence of platinum catalysts to yield 1,4-digermacyclohexa-2,5-dienes in ca. 30% yield. The reactions of phenylacetylene with 1,2-digermacyclohexa-3,5-dienes afforded the corresponding 1,4-digermacycloocta-2,5,7-trienes in 93% yield. Bis(germyl)platinum complexes having various tertiary phosphine ligands have been prepared as models of a key intermediate in the above mentioned catalytic bis-germylation of alkynes, and their structures have been established by spectroscopic methods and X-ray crystallography. Bis(germyl)platinum complexes reacted with phenylacetylene to give the corresponding insertion products, germyl(germylvinyl)platinum species, whose structures have been determined by spectroscopic and X-ray analysis. Germyl(germylvinyl)platinum complexes were found to liberate a bis-germylation product of the alkyne upon heating. The result supports a mechanism involving the oxidative addition of a digermane to a Pt(0) complex, the insertion of an alkyne into one of the two Pt-Ge bonds to give a germyl(germylvinyl)platinum species, and the reductive elimination of the bis-germylation product of the alkyne. Evidence suggesting the extrusion of a germylene unit from the bis-germylplatinum species has been obtained, accounting for the generation courses of other by-products.
Photochemical Reactions of Aryl-Substituted Digermanes through a Pair of Organogermyl Radicals
Mochida, Kunio,Wakasa, Masanobu,Sakaguchi, Yoshio,Hayashi, Hisaharu
, p. 1889 - 1895 (2007/10/02)
The photochemical reactions of aryl-substituted digermanes were investigated by trapping experiments and a laser flash photolysis technique.The photolysis of phenylated digermanes resulted in germanium-germanium bond homolysis to give a pair of two germyl radicals.The germyl radicals abstracted a chlorine atom from carbon tetrachloride to give chlorogermanes.The pair of germyl radicals also underwent ipso-substitution, which was a precursor of the germylenes.The mechanism for the photochemistry of phenylated digermenes is discussed.
New photochemical routes to germylenes and germenes and kinetic evidence concerning the germylene-diene addition mechanism
Bobbitt, Kevin L.,Maloney, Vincent M.,Gaspar, Peter P.
, p. 2772 - 2777 (2008/10/08)
Upon 254-nm irradiation of phenylbis(trimethylsilyl)germanes, there is competition between two germylene-forming reactions, the unexpected elimination of phenyltrimethylsilane and the elimination of hexamethyldisilane. Irradiation of a phenylmonosilylgermane PhGeMe2SiMe3 leads to predominant elimination of PhSiMe3, forming dimethylgermylene Me2Ge:, accompanied by migration of Me3Si to the ortho position of the phenyl ring, forming a germene. Laser flash photolysis of PhGeMe2SiMe3 is a convenient source of Me3Ge:, and rate constants are reported for Me2Ge: addition to a series of dienes and other substrates. The kinetic data are in accord with 1,2-addition as the dominant pathway for addition of Me2Ge: to 1,3-dienes.
Photochemical reactions of aryl-substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge). Formation of a radical pair
Mochida, Kunio,Kikkawa, Haruhiko,Nakadaira, Yasuhiro
, p. 9 - 19 (2007/10/02)
Photochemical reactions of phenyl substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge) have been investigated by chemical trapping experiments and laser flash-photolysis.On irradiation, the phenylated group 4B catenate undergoes E-E' bond homolysis to give a pair of radicals (PhMe2E. and Me3E'.).In CCl4, these radicals are converted to the corresponding chlorides by abstraction of a chlorine atom.In a nonhalogenated solvent, the radical pair couples at the ipso-position of the phenyl group of the pairing radical (PhMe2E.) to yield the cor responding diradical.This undergoes either elimination of a divalent species (Me2E:) with concomitant formation of trimethylphenyl group 4B element PhMe3E') or intramolecular 1,2-group 4B element migration to yield group 4B metal-carbon double bonded species.The radical escapes from the solvent cage coupled to the metal atom of the radical to yield the dimetallic product.The reaction path observed is highly dependent on the nature of the group 4B element comprising the phenyl substituted catenate.
New (diarylgermyl)lithiums
Castel,Riviere,Satge,Ko
, p. 205 - 210 (2008/10/08)
The new (diarylgermyl)lithiums R2GeHLi (2; R = phenyl, mesityl) were prepared in good yields by hydrogermolysis reactions of tert-butyllithium in THF. The stability of compounds 2 depends on the nature of the R group and the solvent. For R = Ph, in the presence of an amine (Et3N or Et2NMe), the same reaction leads to the formation of the polygermanes H(GePh2)nH (n = 2-4). The characterization of compounds 2 by IR and 1H and 13C NMR spectroscopy and their complexation with a crown ether are also reported. They are characterized by deuterolysis and alkylation reaction (with MeI and Me2SO4). Their germylation reactions with Ge-Cl reagents constitute a convenient way for synthesizing organo-hydropolygermanes. Compounds 2 also react with acyl chlorides to give new germyl ketones, R2HGeCOR′, and the unexpectedly stable β-germyl diketone Ph2Ge(COMes)2.
Laser photolysis of aryl-substituted digermanes. Generation of germyl radicals and germylenes
Mochida, Kunio,Wakasa, Masanobu,Nakadaira, Yasuhiro,Sakaguchi, Yoshio,Hayashi, Hisaharu
, p. 1869 - 1871 (2008/10/08)
Laser flash photolysis of the phenyl-substituted digermanes (PhnMe3-nGe)2 results in Ge-Ge bond homolysis to give germyl radicals and probably a germylene.
Arylhydrogermyllithiums: synthese et applications
Castel, Annie,Riviere, Pierre,Satge, Jacques,Ko, Young-Hoon
, p. C1 - C4 (2007/10/02)
New organohydrogermyllithium are prepared in good yields from hydrogermolysis reactions with t-butyllithium in THF.Alkylation and germylation of the germanium-lithium bond in these compounds are efficient reactions and a convenient way for synthesis of organohydropolygermanes.These reagents are also useful for the formation of unknown hydrogermylmagnesium compounds.
Photochemistry of Phenylpentamethyldigermane
Mochida, Kunio,Kikkawa, Haruhiko,Nakadaira, Yasuhiro
, p. 1089 - 1092 (2007/10/02)
Photolysis of phenylpentamethyldigermane afforded hydrogermanes and digermanes, as main products.These are derived from two germyl radicals generated by photo-induced homolysis of the germanium-germanium bond.Dimethylgermylene is shown to be evolved also