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.
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.
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.
