The First Chemical Achievements and Publications by Justus von Liebig (1803-1873) on Metal Fulminates and Some Further Developments in Metal Fulminates and Related Areas of Chemistry

摘要

The first chemical investigations and publications by Justus von Liebig dealt with the fulminates of silver and mercury. Even as a boy Liebig had learnt how to prepare silver fulminate, and as student of chemistry in Erlangen (1821) he studied the properties and reactions of silver fulminate. In Paris in 1823 (together with Gay-Lussac) he succeeded in analyzing quantitatively the highly explosive silver compound. This great experimental success with the dangerous silver fulminate was most important in three respects: i. The development of the experimental method later culminated in Liebigs perfected and well-known C,H,N analysis of organic compounds (1830). ii. It led to the concept of isomerism when F. W?hler found that silver cyanate had the same composition as silver fulminate. iii. It was decisive for furthering the scientific career of Liebig, since Alexander von Humboldt was highly impressed by the great skill and talent of Liebig and - by recommendation of Humboldt - Liebig became Professor in GieBen in 1824 (at the young age of 21). The first (fulminato)metal complex, K[Ag(CNO)_2], was also isolated by Liebig. Later, explosive (fulminato)metal complexes were prepared by Nef, Wieland, and especially by Lothar W?hler and co-workers. In Munich the HCNO structure of fulminic acid was established by its IR spectrum and the spectroscopic properties of (fulminato)metal complexes were studied. A series of new nonexplosive complexes could be obtained by dilution of the energy-rich species with large cations or ligands. Recent X-ray structure determinations have revealed the almost perfect linear, tetrahedral, square-planar, or octahedral structures of these complexes with linear metal-CNO bonds, e.g. [Au(CNO)_2]~-, [Zn(CNO)_4]~(2-), [Ni(CNO)_4]~(2-), [Co(CNO)_6]~(3-). DFT calculations have given very good agreement between the calculated and experimental structural parameters and CNO stretching frequencies. The (fulminato)metal complexes closely resemble the analogous cyano compounds.