Flashback: 50 Years Ago
Angewandte Chemie International Edition was first published in 1962, the mother journal first in 1888. In this monthly flashback, we feature some of the articles that appeared 50 years ago. This look back can open our eyes, stimulate discussion, or even raise a smile.
Archive: 2014 2013 2012
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2015, 54, No. 09, 2578
The chemistry of heterosiloxanes was the subject of a Review by Hubert Schmidbaur, a former Chairman of the Editorial Board of Angewandte Chemie. 50 years later, at the age of 80, Schmidbaur is still actively publishing; his Review on argentophilic interactions appeared in a very recent issue (see Angew. Chem. Int. Ed. 2015, 54, 746).
Ernst Otto Fischer, who shared the 1973 Nobel Prize in Chemistry with Geoffrey Wilkinson, reported on isonitrilocyclopentadienyl complexes of lanthanoids. These complexes were formed by the reaction of lanthanoid tricyclopentadienyl complexes with cyclohexyl isonitrile, and were the first reported examples of compounds where a stable metal–carbon σ bond is formed for rare-earth metals.
Armin Weiss et al. reported on the crystal structure of strontium disilicide. The silicon atoms were found to form a three-dimensional network with Si–Si distances comparable to that of elemental silicon. This structure contrasts with those other disilicides that contain two-dimensional nets or isolated tetrahedra of silicon atoms.
Horst Prinzbach et al. published two Communications on conjugated π-bond systems. The first report described the synthesis of a monobenzo derivative of cyclopropenylidenecyclopentadiene (calicene), which is a highly strained but also delocalized system. Interestingly, a report from Andrew S. Kende on a similar calicene derivative was published shortly afterwards (J. Am. Chem. Soc. 1965, 87, 1609). Prinzbach’s second contribution was on stable methylenephenalene derivatives (phenalenes are three fused six-membered rings). Prinzbach was one of the most influential German organic chemists in the latter half of the last century, and was famous for the synthesis of a range of nonbenzenoid organic compounds, including dodecahedrane (for more details see his Obituary: Angew. Chem. 2012, 51, 11936).
Read more in Issue 3/1965.
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2015, 54, No. 05, 1388
Giulio Natta, who shared the 1963 Nobel Prize in Chemistry with Karl Ziegler, contributed a Review on the analogies between the stereochemical properties of macromolecules and those of classic organic cyclic compounds. In another Review, Dieter Seebach discussed the properties of three- and four-membered polycyclic systems, in particular tetrahedrane, Dewar benzene, prismane, and cubane. Seebach published a Minireview on geminal disubstitution in the 50th Jubilee Issue of Angewandte Chemie International Edition (see Angew. Chem. Int. Ed. 2014, 50, 96).
Hubert Schmidbaur (former Chairman of the Editorial Board of Angewandte Chemie) contributed three Communications on gallium-containing compounds. The first was on the synthesis of dichlorogallane HGaCl2 , which was formed by the reaction of trimethylsilane with gallium trichloride. The second report was on organoheterosilanes Me3SiOXMe2 and Me3COXMe2 (X=Al, Ga, or In), which occur as dimers that have a four-membered ring structure, and the third on the synthesis of trimethylaluminum trimethylphosphorus oxide and trimethylarsenic trimethylgallium oxide. Schmidbaur’s Review on argentophilic interactions is currently in press (see Angew. Chem. Int. Ed. 2014, DOI: 10.1002/anie.201405936).
Hermann Stetter, after whom the Stetter reaction was named, described a new synthesis of the adamantane derivatives substituted in the 3-position, which were constructed by the cyclization of 3-methylenebicyclo[3.3.1]nonan-7-one or 3,7-dimethylenebicyclo[3.3.1]nonane in the presence of acids. This method could also be used to synthesize adamantane-containing polymers.
Read more in Issue 5/1965.
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2015, 54, No. 01, 22
Richard Kuhn et al. reported on the stable triradical 1,3,5-tris-(1,5-diphenylverdazyl-3-yl)benzene, which contains ten conjugated six-membered rings and three unpaired electrons per molecule. Paramagnetic susceptibility and EPR measurements were used to confirm the radical nature of the compound, and it was noted that, unlike related biradicals, its electron spin remained unchanged down to 77 K.
Klaus Hafner et al. discussed the synthesis of pentaleno[2,1,6-def]heptalene. This molecule is a nonbenzenoid isomer of pyrene and can be described as either two pentalene and two heptalene units, or two azulene systems. The compound was of interest for investigating the connection between structure and aromaticity, however it was found that, despite its 4n π electrons, the compound was inert toward electrophilic reagents.
The issue also contained several Reviews on, at that time, contemporary topics in organic chemistry. Wolfgang Kirmse summarized the current knowledge of the intermediates of α-elimination reactions, including a discussion of radical and organometallic (carbanion) intermediates; Adolf W. Krebs discussed the properties of cyclopropenium compounds and cyclopropenones, which are Hückel aromatic (4n+2) π-electron systems; and Gert Köbrich detailed the various possible mechanisms of elimination reactions from olefins.
Read more in Issue 1/1965.