16030-09-4Relevant academic research and scientific papers
Electrochemical and photophysical properties of a series of group-14 metalloles
Ferman, Justin,Kakareka, Joseph P.,Klooster, Wim T.,Mullin, Jerome L.,Quattrucci, Joseph,Ricci, John S.,Tracy, Henry J.,Vining, William J.,Wallace, Scott
, p. 2464 - 2472 (2008/10/08)
A series of six group-14 dimethyl- or diphenyl-tetraphenylmetallacyclopentadienes were synthesized and characterized by their spectroscopic and electrochemical properties. The group-14 elements investigated were silicon, germanium, and tin. (The compounds are designated according to the heteroatom and the substituent on the heteroatom, i.e., SiMe, SiPh, SnPh.) Five of the six compounds luminesce in both the solid state and in solution. The emission maxima of SiPh, GePh, and SnPh are invariant to a change in the heteroatom, while for SiMe, GeMe, and SnMe there is a strong dependence of the emission maxima on the identity of the heteroatom. SiMe emits at a longer wavelength than GeMe, while SnMe is not luminescent. The dramatic luminescence difference between the two tin compounds was investigated. 13C NMR coupling to 119/117Sn, observed in both SnMe and SnPh, was used to make 13C NMR resonance assignments. Qualitative results of semiempirical molecular orbital calculations support the 13C NMR assignments. The crystal structure data for SnPh was obtained at 20 °C: a = 10.353(2) A?, b = 16.679(2) A?, c = 9.482(1) A?, α = 99.91(1)°, β = 106.33(1)°, γ = 77.80(1)° with Z = 2 in space group P1. It is proposed that the increased electron density at tin in SnMe is responsible for the deactivation of the emissive state. The presence of phenyl substituents in SnPh serves to stabilize the emissive state and luminescence is observed.
The dianion of tetraphenylgermole is aromatic
West,Sohn,Powell,Muller,Apeloig
, p. 1002 - 1004 (2008/10/09)
Not one, but two structurally distinct forms are obtained depending upon the crystallization temperature when Li2(Ph(C]4Ge) crystallizes from dioxane. In one form (left) the two lithium ions are located on opposite sides of the germole rings each η5 coordinated to all of the ring of atoms. In the other form (right), one lithium ion is η5 coordinated to the ring atoms and the other is η5 coordinated to the germanium center. The C C distances within the ring of the germole dianion are nearly equal, indicating that the binding is highly delocalized.
Tetraphenylzirkonacyclopentadien-Derivate als Synthone fuer Tetraphenylthiophenmonoxid und substituierte Germanole
Meier-Brocks, Frank,Weiss, Erwin
, p. 33 - 45 (2007/10/02)
Improved syntheses for the five-membered heterocycles 2,3,4,5-tetraphenylthiophene-1-monoxide (1), 1,1-dichloro-2,3,4,5-tetraphenylgermole (3) and 1,1-dimethyl-2,3,4,5-tetraphenylgermole (4) are reported.They make use of bis(η5-cyclopentadienyl)-2,3,4,5-tetraphenyl-1-zirconacyclopentadiene (2), easily prepared in a one-step reaction from Cp2ZrCl2, n-BuLi and diphenylethyne.Further reaction of 2 with SOCl2, GeCl4 or Me2GeCl2 yields the desired products and allows recovery of Cp2ZrCl2.Crystal structure analyses of 1 and 4 demonstrate folded five-membered rings with a diene system.Starting from 3 the following derivatives have been synthesized: Ph4C4Ge(CCR)2 (R = H, t-Bu, Ph), Ph4C4GeCl (10) and Ph4C4GeCl.Moreover spectral data (IR, 1H NMR, 13C NMR) of all compounds and the crystal structure of 10 are reported.
Synthese de germoles par reaction de transmetallation (Groupe 4 (groupe 14))
Dufour, Pascal,Dartiguenave, Michele,Dartiguenave, Yves,Dubac, Jacques
, p. 61 - 69 (2007/10/02)
The transmetallation reaction of group 14 metallacyclopentadienes, Cp2EC4R'4 (E = Ti, Zr, Hf; R' = Ph, Me) with various halogermanes has been studied.The tetrahalides GeCl4 and GeBr4 undergo the E/Ge exchange reaction at room temperature, but the trihalides RGeCl3 and dihalides R2GeCl2 (R = Me, Ph) are less reactive.Some germoles were found to be unstable.A phenyl group on the germanium atom stabilizes the 2,3,4,5-tetramethylgermoles with a Ge-H (HPhGeC4Me4) or Ge-Cl bond (ClPhGeC4Me4).
