Bis(μ-(pentamethylcyclopentadienyl)aluminio)hexacarbonyldicobalt,
(μ-Cp*Al)2Co2(CO)6, is formed
in
the reaction between AlCp* (Cp* = C5Me5)
and Co2(CO)8
in toluene. The bonding description as a polyhedral
Al2Co2 cluster in which AlCp* has completely lost
its
originally carbene-like character is based on X-ray data
as well as on DFT calculations.
Ausgehend von Germanium(I)‐bromid, das durch präparative Cokondensation zugänglich ist, konnte die erste polyedrische Ge‐Clusterverbindung, [Ge8{N(SiMe3)2}6] (siehe Bild), hergestellt werden, in der die mittlere Oxidationsstufe aller Ge‐Atome im Clusterkern zwischen 0 und +1 liegt.
Cocondensation of Al atoms and HCl in argon matrices at ∼4 K led
to detection by ESR of HAlCl and
AlCl2. The ESR spectra observed from the Al/HCl/Argon
system are shown; assignments and analyses of the HAlCl
and AlCl2 spectra are presented. Both species
have a bent form, and the unpaired electron is localized in a
nonbonding,
sp-hybridized orbital of Al pointing away from the ligand atoms.
Ab initio SCF calculations (Gaussian 92) were
performed on AlH2, HAlCl, and AlCl2. The
structural features and spin density distributions deduced from
the
observed hyperfine coupling tensors are in good accord with those given
by the SCF calculations. The reaction
process between HCl and Al was examined by the MNDO molecular orbital
method. The MNDO study indicated
that Al and HCl would undergo spontaneously either the insertion
reaction, HCl + Al → HAlCl, or the displacement
reaction, HCl + Al → H + AlCl, depending on the direction of
approach.
The orange precipitate obtained after the well-known preparation of fluorenyllithium was recrystallized from a solution of benzene or toluene in order to get orange-red crystals which were of sufficient quality for X-ray diffraction. By this procedure we succeeded in redetermining the molecular structure of a donor-free unsubstituted fluorenyllithium compound, which might be the smallest alkali-metal compound containing a donor-free cyclopentadienyl-like ligand within an annelated ring system to date. The description of the bonding situation is based on ab initio calculations as well as on a comparison with analogous compounds.
Verbindungen mit Metall-Metall-Bindungen der Hauptgruppenelemente haben in jüngster Zeit eine unerwartet hohe Aufmerksamkeit erfahren. [1][2][3][4][5] Trotz der jüngsten strukturellen Befunde zu zwei kristallinen Mg 2 R 2 -Verbindungen (R1 = [ArNC(NiPr 2 )NAr] À ; R2= [{ArNCMe} 2 CH] À ; Ar= 2,6-Diisopropylphenyl, iPr = Isopropyl) [2] und trotz zahlreicher theoretischer Studien zu Molekülem mit Mg-Mg-Bindungen [10][11][12] Nachdem sich vor gut 50 Jahren der erste Hinweis auf stabile Erdalkali(I)-halogenide als Irrtum erwiesen hatte, [13] gelang vor knapp 40 Jahren der erste ESR-spektroskopische Nachweis unter anderem von MgF in einer Edelgasmatrix. [18] Hierzu wurde MgF 2 bei 1250 8C verdampft, die gasförmigen MgF 2 -Moleküle bei 2350 8C zu MgF und F-Atomen dissoziiert und anschließend in der Matrix abgeschieden.[19] Um zu einem für Synthesestudien praktikablen Verfahren analog zur AlCl-Synthese bei 900 8C zu gelangen, [6]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.