Anthracene-assisted inverse transport growth and superconductivity at 3.3 K in unsupported ultrathin {110} Nb and {0001} NbSe2nanoplates

High-quality ultrathin {0001} NbSe2and {110} Nb nanoplatesviaanthracene vapor-assisted hierarchical collapse of constituent NbSe2.

Metall-π-Komplexe von Benzolderivaten, XXI [1]. Bis(η1.2.3.4.4a.9a-anthracen)chrom und Bis(η1.2.3.4.4a.9a-9.10-dihydroanthrancen)- chrom durch Metallatom-Ligand-Cokondensation / Metal-π-Complexes of Benzene Derivatives, XXI [1]. Bis(η1.2.3.4.4a.9a-anthracene)chromium and Bis(η1.2.3.4.4a.9a-9,10-dihydroanthracene)chromium via Metal Atom Ligand Cocondensation

Cocondensation of chromium atoms with anthracene vapor affords bis(η1.2.3.4.4a.9a-anthracene)- chromium (1) which was characterized as the radical cation 1+̣ in fluid solution by means of ESR spectroscopy. Conspicuous features of this new π-complex are the ease of ligand displacement (τ1/2 ≈ 10 min. THF, 233 K) and the ready hydrogenation in 9,10-position of the ligand which already occurs under mild conditions (e.g. methanol). The product of hydrogenation, bis (η1.2.3.4.4a.9a-9,10-dihydroanthracene)chromium (2) was synthesized independently and studied by 1H, 13C NMR (2) and ESR(2+̣) spectroscopy. A qualitative rationalization is given for the observed trend of increasing lability and propensity to hydrogenation: (η6-biphenyl)2chromium < (η6-phenanthrene)2chromium < (η6-naphthalene)2chromium < (η6-anthracene)2chromium.