Bisguanidines with biphenyl, binaphthyl, and bipyridyl cores: proton-sponge properties and coordination chemistry

Herein, we report on the synthesis, protonation, and coordination chemistry of chelating guanidine ligands with biphenyl, binaphthyl, and bipyridyl backbones. The ligands are shown to be proton sponges, and this protonation was studied experimentally and by using quantum-chemical calculations. Group...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Maronna, Astrid Christine (VerfasserIn) , Hübner, Olaf (VerfasserIn) , Enders, Markus (VerfasserIn) , Kaifer, Elisabeth (VerfasserIn) , Himmel, Hans-Jörg (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: May 22, 2013
In: Chemistry - a European journal
Year: 2013, Jahrgang: 19, Heft: 27, Pages: 8958-8977
ISSN:1521-3765
DOI:10.1002/chem.201204294
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1002/chem.201204294
Verlag, lizenzpflichtig, Volltext: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/chem.201204294
Volltext
Verfasserangaben:Astrid Maronna, Olaf Hübner, Markus Enders, Elisabeth Kaifer, and Hans-Jörg Himmel
Beschreibung
Zusammenfassung:Herein, we report on the synthesis, protonation, and coordination chemistry of chelating guanidine ligands with biphenyl, binaphthyl, and bipyridyl backbones. The ligands are shown to be proton sponges, and this protonation was studied experimentally and by using quantum-chemical calculations. Group 10 metal (Ni, Pd, and Pt) complexes with different metal/ligand ratios were synthesized. In the case of the bipyridyl systems, coordination occurs exclusively at the pyridine N atoms, as opposed to protonation. The spin-density distribution and the magnetism were evaluated for a series of paramagnetic NiII complexes with the aid of paramagnetic NMR spectroscopic studies in alliance with quantum-chemical calculations and magnetic (SQUID) measurements. Through direct delocalization from the singly occupied molecular orbitals (SOMOs), a significant amount of spin density is placed on the guanidinyl groups, and spin polarization also transports spin density onto the aromatic backbone.
Beschreibung:Gesehen am 23.06.2021
Beschreibung:Online Resource
ISSN:1521-3765
DOI:10.1002/chem.201204294