220525-60-0Relevant articles and documents
CrIII as an alternative to RuII in metallo-supramolecular chemistry
Zare, Davood,Doistau, Benjamin,Nozary, Homayoun,Besnard, Céline,Guénée, Laure,Suffren, Yan,Pelé, Anne-Laure,Hauser, Andreas,Piguet, Claude
supporting information, p. 8992 - 9009 (2017/07/24)
Compared to divalent ruthenium coordination complexes, which are widely exploited as parts of multi-component photonic devices, optically active trivalent chromium complexes are under-represented in multi-metallic supramolecular architectures performing energy conversion mainly because of the tricky preparation of stable heteroleptic CrIII building blocks. We herein propose some improvements with the synthesis of a novel family of kinetically inert heteroleptic bis-terdentate mononuclear complexes, which can be incorporated into dinuclear rod-like dyads as a proof-of-concept. The mechanism and magnitude of intermetallic Cr?Cr communication have been unraveled by a combination of magnetic, photophysical and thermodynamic investigations. Alternated aromatic/alkyne connectors provided by Sonogashira coupling reactions emerge as the most efficient wires for long-distance communication between two chromium centres bridged by Janus-type back-to-back bis-terdentate receptors.
From 1,2,4-triazines and tributyl(ethynyl)tin to stannylated bi- and terpyridines: The cycloaddition pathway
Sauer, Juergen,Heldmann, Dieter K.,Pabst, Gunther R.
, p. 313 - 321 (2007/10/03)
Recently, we reported on cycloadditions between electron-deficient heterodienes and tributyl(ethynyl)tin, which provide a new pathway to stannylated pyridazines and, in one special case, pyridines. In order to broaden the synthetic scope of these reactions, we have developed hetero [4+2] cycloaddition reactions between a number of tailor-made 1,2,4-triazines 5-9 (acting as heterodienes), and tributyl(ethynyl)tin (acting as dienophile). The desired 1,2,4triazines are readily available, in moderate to very good yields, by the condensation reactions of appropiate carbamidrazones and glyoxals. These cycloadditions open up a novel route to regiospecifically stannylated 2,2'-bi- and 2,2',6',2''-terpyridines 1-4, 11 in good yields. The stannanes 1-4, 11 are versatile synthetic intermediates, and with this strategy various substituents can be incorporated directly by substitution of the stannyl group, as was shown for halogens and carbon electrophiles under Stille conditions.
