Synthesis, Characterization, and Theoretical Investigation of Two-Coordinate Palladium(0) and Platinum(0) Complexes Utilizing π-Accepting Carbenes.
An elegant general synthesis route for the preparation of two coordinate palladium(0) and platinum(0) complexes was developed by reacting commercially available tetrakis(triphenylphosphine)palladium/platinum with π-accepting cyclic alkyl(amino) carbenes (cAACs). The complexes are characterized by NMR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. The palladium complexes exhibit sharp color changes (crystallochromism) from dark maroon to bright green if the C-Pd-C bond angle is sharpened by approximately 6°, which is chemically feasible by elimination of one lattice THF solvent molecule. The analogous dark orange-colored platinum complexes are more rigid and thus do not show this phenomenon. Additionally, [(cAAC)2 Pd/Pt] complexes can be quasi-reversibly oxidized to their corresponding [(cAAC)2 Pd/Pt](+) cations, as evidenced by cyclic voltammetry measurements. The bonding and stability are studied by theoretical calculations.
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Sudipta
S
Roy
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Kartik Chandra
KC
Mondal
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Jann
J
Meyer
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Benedikt
B
Niepötter
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Christian
C
Köhler
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany).
Regine
R
Herbst-Irmer
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany). dstalke@chemie.uni-goettingen.de.
Dietmar
D
Stalke
Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, Raum AC 15c (Erdgeschoss), 20146 Hamburg (Germany).
Birger
B
Dittrich
Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 35032 Marburg (Germany).
Diego M
DM
Andrada
Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 35032 Marburg (Germany). frenking@chemie.uni-marburg.de.
Gernot
G
Frenking
Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077-Göttingen (Germany). hroesky@gwdg.de.
Herbert W
HW
Roesky
carbenes; crystallochromism; density functional calculations; palladium; platinum