摘要:

AbstractIn this article the world's potential energy reserves are summarized on the basis of available estimates, and the future energy consumption is estimated with the aid of a working hypothesis relating to the growth of the world's population (P) and the energy consumption per capita (γ). According to this estimate, the energy requirements in 30 years will be about seven times and in 80 years about fifty times as high as they are today, and all the concentrated energy sources will be exhausted in about 120 to 160 years. – The energy requirements in the steady state (Pγ= const.) could be of the order of 1013MWh per year and could be met out of magmatic rocks (U,Th) and sea water (U,D). High priority should be given to research and development work on the construction, reliability, and safety of breeder and fusion reactors, the chemical treatment and final disposal of radioactive waste, the extraction of uranium, thorium, and deuterium from the “primitive” raw materials, the relevant problems relating to protection of the environment, and the worldwide control of the excess bi

ISSN:0570-0833    

DOI:10.1002/anie.197100011

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractValence isomerization and the phenomenologically related principle of valence tautomerism, as they apply to several nitrogen‐containing heterocyclic systems, are discussed herein. Attention is called first to 1H‐azepines and the reluctance of such substances to isomerize to azanorcaradienes. The role of homo‐1H‐azepines in this context is then briefly outlined. Azocines (azacyclooctatetraenes) are seen to occupy an interesting position in the sense that pronounced shifts in the position of equilibrium (from almost entirely monocyclic to virtually completely bicyclic) occur with substitutional alterations of various types. The capability of azabullvalenes for degenerate valence isomerization is the next presented, and contrast is made with the properties of benzazabullvalenes and an azasemibullvalene der

ISSN:0570-0833    

DOI:10.1002/anie.197100111

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractDuring recent years, instead of concentrating on the detection of the intermediacy of new hetarynes, as they did between 1958 and 1964, workers in this field have been more concerned with the critical sifting and checking of the earlier work. Special interest has been shown in the relation between structure and reactivity in the hetarynes. It has been shown that in addition to the elimination‐addition mechanism (EA; hetaryne intermediate), other reaction paths (anomalous addition‐elimination mechanism [AEa] and “Reinecke mechanism”) are possible for nucleophilic cine‐substitutions on hetaryl halides. The use of deuterated hetaryl halides has proved very valuable for the elucidation of the mechanism of nucleophilic substitutions. Even where substitution mechanisms are superimposed on one another the occurrence of a hetaryne intermediate can be detected by a technique known as the “base competition method”. A five‐membered hetaryne (4,5‐didehydro‐1‐methylimidazole) has been detected for the first time by this method with a probability that borders on certainty. Selectivity determinations have shown that the replacement of a CH group in 1,2‐didehydrobenzene and in 1,2‐didehydronaphthalene by an N atom distinctly increases the reactivity to bases. According to EHT (Extended Hückel Theory) calculations, the as yet hypothetical 2,3‐didehydropyridine is richer in energy than 3,4‐didehydropyridine, this agrees more closely with the experimental findings than the opposite result obtained from simple MO calculations. Besides cine‐substitution (1,2 shift), tele‐substitution (1,3‐shift) has also been observed on reaction of hetaryl halides (pyridine, quinoline, and pyrimidine systems) with bases. An EA mechanism (via m‐didehydrohetarenes) and an AEamechanism are considered as

ISSN:0570-0833    

DOI:10.1002/anie.197100201

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractNumerous clinically used compounds having favorable tranquilizing and toxic properties possess the 1,4‐benzodiazepine skeleton. This group of active substances is readily accessible, e.g. by ring enlargement of quinazoline derivatives, by ring contraction of benzoxadiazocines, and by synthesis from aminobenzophenones, constructing the seven‐membered ring in many cases in one step. The relationships between type and position of substituents and the pharmacological properties are illustrated using 1,3‐dihydro‐5‐phenyl‐1,4‐benzodiazepin‐2

ISSN:0570-0833    

DOI:10.1002/anie.197100341

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractTwo types of reaction are distinguished in solid state chemistry: those in which high mobility of the reactants is aimed at (which can be achieved by the use of high temperatures, by the introduction of defects, by the promotion of surface diffusion, or by means of chemical transport phenomena), and those reactions in which the nature of the products is determined by existing structural elements or lattice defects of the reactants. The importance of paying more attention than hitherto to reaction pathways in preparative solid state chemistry is pointed out.

ISSN:0570-0833    

DOI:10.1002/anie.197100431

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

摘要:

AbstractA number of amines are of the utmost importance to the normal function of the nervous system; numerous relationships also exist between certain diseases of the nervous system and the metabolism of these amines. Noradrenaline, serotonin, and histamine are taken as examples to offer some idea of the possibilities and methods of biochemical research that help to elucidate the physiological and pathological processes in the nervous system. The article shows that our knowledge of the functioning of the nervous system, even in a field that has been studied as thoroughly as the transmission of nerve stimuli at synapses, is still in its infancy.

ISSN:0570-0833    

DOI:10.1002/anie.197100511

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197100661

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197100672

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197100681

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.197100701

出版商:Hüthig&Wepf Verlag    

年代:1971

数据来源: WILEY