Enhanced quantum yields by sterically demanding aryl-substituted β-diketonate ancillary ligands

• Rebecca Pittkowski and
• Thomas Strassner

Beilstein J. Org. Chem. 2018, 14, 664–671, doi:10.3762/bjoc.14.54

• β-diketonates on the emission properties of C^C* cyclometalated complexes, employing the unsubstituted methyl-phenyl-imidazolium ligand. The quantum yield was significantly enhanced by changing the auxiliary ligand from acetylacetonate, where the corresponding platinum(II) complex shows only a very

• weak emission, to mesityl (mes) or duryl (dur) substituted acetylacetonates. The new complexes show very efficient emission with quantum yields >70% in the sky-blue spectral region (480 nm) and short decay times (<3 μs). Keywords: ancillary ligand; β-diketonates; photoluminescence; platinum(II

Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

• Matthias Böttger,
• Björn Wiegmann,
• Steffen Schaumburg,
• Peter G. Jones,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2012, 8, 1037–1047, doi:10.3762/bjoc.8.116

• their triple positive charge, this coordination sphere must be saturated to achieve high quantum yields when the target is to optimize its luminescent properties [6]. In the “classic” complexes, i.e., the β-diketonates [6][7], this is often achieved by combining three “saturating ligands” that consist

• of negatively charged β-diketonates with a “neutral ligand”, which is often bidentate or tridentate (Scheme 1, left). The coordination sphere and the positive charge of the rare-earth metal cation are thus saturated and neutralized, respectively. In a recent development, the Bünzli group has

Synthesis and mesomorphic properties of calamitic malonates and cyanoacetates tethered to 4-cyanobiphenyls

• Katharina C. Kress,
• Martin Kaller,
• Kirill V. Axenov,
• Stefan Tussetschläger and
• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 371–378, doi:10.3762/bjoc.8.40

• investigate the phase behaviour of metal β-diketonate complexes such as 1 [15] (Scheme 1). Although they were not able to detect any mesophases, their study motivated others to examine the mesomorphic properties of β-diketonates in more detail [16]. Among the first examples of a nematic β-diketonate is the Cu

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• from their synergy. Molecular structure of NIRPAC: a Pd(II) complex based on Nile red and a curcumin derivative. Molecular structure of Pd(II) complexes based on functionalised 2-phenylquinolines and β-diketonates. Some unusual palladiomesogens based on 3,5-disubstituted-2,2′-pyridylpyrroles and β

• -diketonates. Molecular structure of Pt(II) complexes based on 4,4′-disubstituted 2,2′-bipyridines. Molecular structure of Zn(II) complexes based on polycatenar 4,4′-disubstituted 2,2′-bipyridines. Molecular structure of a gallium(III) mesogen. Acknowledgments Financial support received from the Ministero