53572-89-7Relevant academic research and scientific papers
Electrochemical synthesis of polygermanes
Okano,Takeda,Toriumi,Hamano
, p. 659 - 666 (2008/10/08)
Five dialkyl-substituted and three phenyl substituted polygermanes were electrochemically synthesized. Among them, dibutyl-, dipentyl-, and dihexyl-substituted polygermanes gave the best synthetic results, i.e., relatively high yields (25-45%), high curre
Catalytic synthesis of poly(arylmethylgermanes) by demethanative coupling: A mild route to σ-conjugated polymers
Katz, Sandra M.,Reichl, Jennifer A.,Berry, Donald H.
, p. 9844 - 9849 (2007/10/03)
A variety of poly(arylmethylgermanes) have been synthesized from aryldimethylgermanes in high yield via mild catalytic demethanative coupling using tetrakis(trimethylphosphine)dimethylruthenium as a convenient catalyst precursor. Polymerizations of germanes Me2GeArH (At = phenyl, p-tolyl, p- fluoro, p-trifluorotolyl, p-anisyl, and m-xylyl) proceed in neat monomer at room temperature. Catalyst removal can be effected by treatment of the reaction mixture with air, which gives polymer yields between 70% and 100%. Alternatively, separation of the catalyst by precipitation of the polymers from THF solution with methanol gives lower yields, but of somewhat higher molecular weight material. The new polygermanes are characterized by 1H NMR and by gel permeation chromatography (GPC) using both polystyrene standards and light scattering methods. Molecular weights calculated by polystyrene analysis fall in the ranges of M(w) = 3 x 103 to 7 x 103 and M(n) = 2 x 103 to 6 x 103. Values obtained from light scattering are approximately 60% and 82% higher, respectively, resulting in M(w) measured by SEC/LS in the range 5 x 103 to 1 x 104, with M(w)/M(n) ~ 1.3. The absorption spectra of the polygermanes exhibit λ(max) in the range 326-338 nm. Comparison of the properties of poly(phenylmethylgermane) prepared by catalytic demethanative coupling and Wurtz coupling of MePhGeCl2 with sodium revealed no significant differences.
Synthesis, absorption characteristics and some reactions of polygermanes
Mochida, Kunio,Chiba, Hiromi
, p. 45 - 54 (2007/10/02)
A number of high molecular weight polygermanes were prepared by an improvement on Wurtz coupling reactions of dichlorogermanes and sodium metal, and by a method using diiodogermylene and Grignard reagents (or organolithiums).Most of the polygermanes thus prepared showed a narrow molecular distribution containing molecular weights 103-104.In solution, the polygermanes showed characteristic electronic absorption bands at 300-350 nm and were strongly thermochromic for alkyl-substituted derivatives.Photolysis of the polygermanes proceeded by both contraction of the chain with loss of diorganogermylenes and homolytic scission of the germanium-germanium ? bond. Key words: Germanium; Polygermane; Photochemistry
Laser flash photolysis of polygermanes. Generation of germylenes and polygermyl radicals
Mochida, Kunio,Kimijima, Kohichi,Chiba, Hiromi,Wakasa, Masanobu,Hayashi, Hisaharu
, p. 404 - 406 (2008/10/08)
Laser flash photolysis of polygermanes involves both Ge-Ge bond homolysis to give polygermyl radicals and extrusion of germylenes.
Electronic absorption spectra of diorganogermylenes in matrices: Formation of diorganogermylene complexes with heteroatom-containing substrates
Ando, Wataru,Itoh, Hiroyuki,Tsumuraya, Takeshi
, p. 2759 - 2766 (2008/10/08)
Diorganogermylenes were generated in hydrocarbon matrices at 77 K by the photolysis of 7-germanorbornadienes 1a-e or bis(trimethylsilyl)germanes 2a-g. The germylenes show electronic absorption bands at 420-558 nm. The germylenes react with heteroatom-containing substrates (R2O, R2S, R3P, R3N, RCl, and ROH) to form adducts, which show characteristic absorption bands at shorter wavelengths than those of germylenes.
