Cyanides history

Cyanide complexes have a venerable history (see CCC S )),1 and find utilization in many industrial processes including as synthetic catalysts e.g., Co cyanides on inorganic supports catalyze alkylene oxide polymerization,187 molecular magnetic materials, in electroplating, and in mining. Their pharmacology and toxicology is well explored... 

Officially, the history of MCRs dates back to the year 1850, with the introduction of the Strecker reaction (S-3CR) describing the formation of a-aminocyanides from ammonia, carbonyl compounds, and hydrogen cyanide [4]. In 1882, the reaction progressed to the Hantzsch synthesis (H-4CR) of 1,4-dihydropyridines by the reaction of amines, aldehydes, and 1,3-dicarbonyl compounds [5], Some 25 years later, in 1917, Robinson achieved the total synthesis of the alkaloid tropinone by using a three-component strategy based on Mannich-type reactions (M-3CR) [6]. In fact, this was the earliest application of MCRs in natural product synthesis [7]. 

Edmond Becquerel (1820-1891) was the nineteenth-century scientist who studied the phosphorescence phenomenon most intensely. Continuing Stokes s research, he determined the excitation and emission spectra of diverse phosphors, determined the influence of temperature and other parameters, and measured the time between excitation and emission of phosphorescence and the duration time of this same phenomenon. For this purpose he constructed in 1858 the first phosphoroscope, with which he was capable of measuring lifetimes as short as 10-4 s. It was known that lifetimes considerably varied from one compound to the other, and he demonstrated in this sense that the phosphorescence of Iceland spar stayed visible for some seconds after irradiation, while that of the potassium platinum cyanide ended after 3.10 4 s. In 1861 Becquerel established an exponential law for the decay of phosphorescence, and postulated two different types of decay kinetics, i.e., exponential and hyperbolic, attributing them to monomolecular or bimolecular decay mechanisms. Becquerel criticized the use of the term fluorescence, a term introduced by Stokes, instead of employing the term phosphorescence, already assigned for this use [17, 19, 20], His son, Henri Becquerel (1852-1908), is assigned a special position in history because of his accidental discovery of radioactivity in 1896, when studying the luminescence of some uranium salts [17]. 

History. Braun and Tschemak [23] obtained phthalocyanine for the first time in 1907 as a byproduct of the preparation of o-cyanobenzamide from phthalimide and acetic anhydride. However, this discovery was of no special interest at the time. In 1927, de Diesbach and von der Weid prepared CuPc in 23 % yield by treating o-dibromobenzene with copper cyanide in pyridine [24], Instead of the colorless dinitriles, they obtained deep blue CuPc and observed the exceptional stability of their product to sulfuric acid, alkalis, and heat. The third observation of a phthalocyanine was made at Scottish Dyes, in 1929 [25], During the preparation of phthalimide from phthalic anhydride and ammonia in an enamel vessel, a greenish blue impurity appeared. Dunsworth and Drescher carried out a preliminary examination of the compound, which was analyzed as an iron complex. It was formed in a chipped region of the enamel with iron from the vessel. Further experiments yielded FePc, CuPc, and NiPc. It was soon realized that these products could be used as pigments or textile colorants. Linstead et al. at the University of London discovered the structure of phthalocyanines and developed improved synthetic methods for several metal phthalocyanines from 1929 to 1934 [1-11]. The important CuPc could not be protected by a patent, because it had been described earlier in the literature [23], Based on Linstead s work the structure of phthalocyanines was confirmed by several physicochemical measurements [26-32], Methods such as X-ray diffraction or electron microscopy verified the planarity of this macrocyclic system. Properties such as polymorphism, absorption spectra, magnetic and catalytic characteristics, oxidation and reduc-... 

Although the hydrogenation of hydrogen cyanide to methylamine was achieved as early as 1863 (Debus, 1), the history of modern catalytic hydrogenation began in 1897 with the discovery by Paul Sabatier and R. Senderens of the vapor phase hydrogenation of unsaturated compounds over a nickel catalyst (Sabatier and Senderens, 2). Sabatier has said that his interest in the action of nickel was provoked by the newly discovered Mond process for the purification of nickel by the formation and decomposition of nickel carbonyl. The capacity of nickel... 

This account of the literature in the area of paramagnetic cyanide compounds is intended to inform the readers of the breadth of the field and the exciting possibilities that still exist. The 300-year old history of PB and the plethora of publications in the field of cyanide chemistry that have appeared over the past 50-60 years notwithstanding, there are many new horizons in the field that remain to be explored. In this section, we highlight some of the key challenges as they pertain to molecular magnetism. 

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