SYNTHESIS OF MIXED LIGAND METAL COMPLEX OF CU (II) WITH SCHIFF BASE AND THIOACETAMIDE

Complex compounds were identified in the 19th century. The formation of hexammine cobalt(III) chloride [CO (NH3)6] Cl3 which is prepared from cobalt chloride and ammonia is thefirst compound, studied and real beginning of coordination Chemistry [1]. Alfred Werner firstexplained the nature of bonding and structure of these complexes and he was awarded NoblePrize in 1913 [2]. He gave the concept of primary (ionisable) valency and secondary(unionsible) valencies of metal ion.

DIGITAL – SMART – MENSCHENZENTRIERT: Smart Hospital UK-Essen

Professor Dr. Jochen Alfred Werner gilt als „Medical Influencer“ für die digitale Transformation im Gesundheitssektor. Als Ärztlicher Direktor und Vorstandsvorsitzender treibt er die Entwicklung des Universitätsklinikums Essen zum „Smart Hospital“ maßgeblich mit an. Im Mittelpunkt steht für ihn dabei: der Mensch. Wir haben Professor Werner gefragt, wie sich ein Smart Hospital von anderen Kliniken unterscheidet.

Serendipity: Werner's argument that the `two-only forms' (green and violet) of [CoCl2(en)2]+ salts demanded his octahedral model was correct. True?

Chemists of the late 19th century, including Alfred Werner, prepared salts containing either green or violet cations of composition [CoCl2(en)2]+ (en is ethylenediamine, C2H8N2); we now refer to these as trans-dichloro and cis-dichloro species. We have discovered a third salt, purple in color, containing cations of the same elemental composition and whose asymmetric unit composition is [CoCl2(en)2]2Cl2·3H2O, in which the cobalt cations are a cis:trans dichloro pair. Such a discovery would undermine Werner's argument that if only two forms can be prepared, his octahedral theory was proven. Probably because his students never examined their crystals under a microscope, they failed to observe the `third' species, thereby ruining Werner's argument since he relied strictly on color to identify them. That was fortunate since our purple salt would have led him to abandon, or certainly delay, his momentous discovery. Our crystals consist of a 1:1 mixture of the cis and trans cations, thereby sharing the same elemental analysis and conductivity as the single salts, but not their crystal structure, inasmuch as X-ray diffraction had not even been discovered then. Serendipitously, our discovery would have been a great boon to his theoretical acumen, while his `two-color' argument may have doomed him.

Periodic law and system of chemical elements: 150 years from the date of discovery

The data concerning the formulation of the Periodic Law and certain graphic variants of its interpretation, proposed at different times for 150 years from the moment of the opening of this law, have been presented and discussed. It was stated that, despite the presence of a very significant (several hundred) number of these variants, only two tabular versions of the Periodic Table of chemical elements, namely, the so-called “short-periodic” proposed by Dmitri Mendeleev and the so-called “long-periodic” proposed by Alfred Werner (which was recommended in the fullness of time by the International Union of Pure and Applied Chemistry), received practical applications. A modification of the indicated tabular variants, aimed at overcoming their shortcomings, has been proposed. The question of the existence of the upper boundary of the Periodic System and the probable prospects for obtaining super-heavy elements with a nuclear charge of Z > 110, in particular a new category of them – 5g-elements, has been also discussed.