TY - JOUR
T1 - Oligonuclear molecular models of intermetallic phases
T2 - A case study on [Pd 2Zn 6Ga 2(Cp*) 5(CH 3) 3]
AU - Bollermann, Timo
AU - Molon, Mariusz
AU - Gemel, Christian
AU - Freitag, Kerstin
AU - Seidel, Rüdiger W.
AU - Von Hopffgarten, Moritz
AU - Jerabek, Paul
AU - Frenking, Gernot
AU - Fischer, Roland A.
PY - 2012/4/16
Y1 - 2012/4/16
N2 - The synthesis, characterization, and theoretical investigation by means of quantum-chemical calculations of an oligonuclear metal-rich compound are presented. The reaction of homoleptic dinuclear palladium compound [Pd 2(μ-GaCp*) 3(GaCp*) 2] with ZnMe 2 resulted in the formation of unprecedented ternary Pd/Ga/Zn compound [Pd 2Zn 6Ga 2(Cp*) 5(CH 3) 3] (1), which was analyzed by 1H and 13C NMR spectroscopy, MS, elemental analysis, and single-crystal X-ray diffraction. Compound 1 consisted of two C s-symmetric molecular isomers, as revealed by NMR spectroscopy, at which distinct site-preferences related to the Ga and Zn positions were observed by quantum-chemical calculations. Structural characterization of compound 1 showed significantly different coordination environments for both palladium centers. Whilst one Pd atom sat in the central of a bi-capped trigonal prism, thereby resulting in a formal 18-valence electron fragment, {Pd(ZnMe) 2(ZnCp*) 4(GaMe)}, the other Pd atom occupied one capping unit, thereby resulting in a highly unsaturated 12-valence electron fragment, {Pd(GaCp*)}. The bonding situation, as determined by atoms-in-molecules analysis (AIM), NBO partial charges, and molecular orbital (MO) analysis, pointed out that significant Pd-Pd interactions had a large stake in the stabilization of this unusual molecule. The characterization and quantum-chemical calculations of compound 1 revealed distinct similarities to related M/Zn/Ga Hume-Rothery intermetallic solid-state compounds, such as Ga/Zn-exchange reactions, the site-preferences of the Zn/Ga positions, and direct M-M bonding, which contributes to the overall stability of the metal-rich compound.
AB - The synthesis, characterization, and theoretical investigation by means of quantum-chemical calculations of an oligonuclear metal-rich compound are presented. The reaction of homoleptic dinuclear palladium compound [Pd 2(μ-GaCp*) 3(GaCp*) 2] with ZnMe 2 resulted in the formation of unprecedented ternary Pd/Ga/Zn compound [Pd 2Zn 6Ga 2(Cp*) 5(CH 3) 3] (1), which was analyzed by 1H and 13C NMR spectroscopy, MS, elemental analysis, and single-crystal X-ray diffraction. Compound 1 consisted of two C s-symmetric molecular isomers, as revealed by NMR spectroscopy, at which distinct site-preferences related to the Ga and Zn positions were observed by quantum-chemical calculations. Structural characterization of compound 1 showed significantly different coordination environments for both palladium centers. Whilst one Pd atom sat in the central of a bi-capped trigonal prism, thereby resulting in a formal 18-valence electron fragment, {Pd(ZnMe) 2(ZnCp*) 4(GaMe)}, the other Pd atom occupied one capping unit, thereby resulting in a highly unsaturated 12-valence electron fragment, {Pd(GaCp*)}. The bonding situation, as determined by atoms-in-molecules analysis (AIM), NBO partial charges, and molecular orbital (MO) analysis, pointed out that significant Pd-Pd interactions had a large stake in the stabilization of this unusual molecule. The characterization and quantum-chemical calculations of compound 1 revealed distinct similarities to related M/Zn/Ga Hume-Rothery intermetallic solid-state compounds, such as Ga/Zn-exchange reactions, the site-preferences of the Zn/Ga positions, and direct M-M bonding, which contributes to the overall stability of the metal-rich compound.
KW - cluster compounds
KW - density functional calculations
KW - main group elements
KW - structure elucidation
KW - transition metals
UR - http://www.scopus.com/inward/record.url?scp=84859571545&partnerID=8YFLogxK
U2 - 10.1002/chem.201102758
DO - 10.1002/chem.201102758
M3 - 文章
AN - SCOPUS:84859571545
SN - 0947-6539
VL - 18
SP - 4909
EP - 4915
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 16
ER -