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1. |
Stabilization of Unusual Oxidation and Coordination States by the Ligands OSF5, OSeF5, and OTeF5 |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 877-888
Konrad Seppelt,
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摘要:
AbstractCompounds with the ligands OSF5, OSeF5, and OTeF5are now known for most of the chemical elements. The ability of these ligands to stabilize the highest valency levels of the central atoms to which they are bound is unsurpassed by any other polyatomic ligand. Examples are Xe(OTeF5)6, Te(OTeF5)6, W(OTeF5)6, and U(OTeF5)6or I(OTeF5)5and Br(OSeF5)3. Because of the ligands' size and internal bonding they hardly ever form bridges, and in this respect they differ from fluorine, although they do share the latter's high electronegativity.
ISSN:0570-0833
DOI:10.1002/anie.198208773
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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2. |
Organometallic Intramolecular π‐Olefin‐Metal Coordination Compounds |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 889-902
Iwao Omae,
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摘要:
AbstractIn this review article complexes of the type XnM—R are dealt with in which a σ‐bonded organic ligand R is additionally linked by a π‐bond with the metal M. In other words, the complexes contain metallacycles with three and a half, four and a half, five and a half members,etc.Well‐Known five and a half membered ring systems are those with 4‐pentenyl, 1,4‐pentadienyl, norbornyl norbornenyl, cyclooctenyl, andendo‐dicyclopentadienyl ligands. Metallacycles of this size are strain‐free and stable. Donor ligands such as amines and phosphanes can displace the coordinated double bond of the π‐ligand from the metal. This CC double bond is lengthened fromca.133 pm to 136–14
ISSN:0570-0833
DOI:10.1002/anie.198208891
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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3. |
The Leukotrienes, Highly Biologically Active Substance Involved in Allergy and Inflammation |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 902-910
Bengt Samuelsson,
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摘要:
AbstractArachidonic acid, a fourfold unsaturated C20‐fatty acid, has attracted interest over the last 15 years far beyond the bounds of nutritional research. It forms an essential acyl component of the phospholopids in all animal cells. The long know fact that certain unsaturated fatty acids must be contained in the diet in order to ensure normal function of the organism has been explained by the discovery of a broad palette of biologically highly active oxidation products of arachidonic acid, a cascade, as it is often referred to. Arachidonic acid is formed in organisms from linoleic and linolenic acids, which belong to the so‐called essential fatty acids. As early as 1935Ulf von Eulerwas able to detect a substance in semen which caused smooth muscles to contract. This factor, which was later isolated in pure form, was termed prostaglandin. The number of prostaglandins, including the synthetically obtained analogues, then rapidly increased. Prostaglandins are biosynthesized from arachidonic acid and similar C20‐fatty acids by enzymatic oxidation with a cyclooxygenase. Its activity is inhibited by acetylsalicylic acid, indomethazine, and other substances, because these relieve or cure inflammations arising from the action of certain prostaglandins. After the prostaglandins, the thromboxanes, which promote aggregation of blood platelets and thus cause thrombosis, were discoverd as further metabolic products of arachidonic acid. In a well‐balanced equilibrium the thromboxanes have a biological effect completely opposite to that of prostacyclin, discovered soon after this, which inhibits platelet aggregation. Both of these biologically active substances are metabolites of arachidonic acid, and are formed in the course of the cyclizing oxidation. Aspirin and substances having a similar mode of action, therefore have an influence on thrombosis. There are, however, contraction processes and inflammation symptoms which do not respond to these substances, but to steroid hormones (cortisone). For symptoms of this type, to which asthma also belongs, the most recently discovered metabolic products of arachidonic acid are probably highly decisive; they are formed by another enzymatic routeviaa hydroperoxide of arachidonic acid. These compounds are formed in leukocytes and contain the triply unsaturated structural element of a triene and were, therefore, termed leukotrienes. Their astonishingly high histamine‐like activity in producing contraction of lung capillaries, their marked property of making capillary vessels permeable to blood plasma,i.e.of generating oedema, the ability of leukotriene LTB4to cause adherence of human leukocytes and their adhesion to the endothelium, make the leukotrienes chemical mediators in allergies and inflammations, and produce biological effects when present at minute concentrations. In the following article one of the three scientists who were awarded this years Nobel prize for medicine and physiology, and who provided an explanation for this extraordinarily interesting class of natural products, gives an account of the conversion of arachidonic acid into the labile epoxide LTA4and further into the dihydroxy compound LTB4, or the glutathione cysteinylglycine and cysteine conjugates LTC4. LTD4, and LTE4, respectively, as well as of the physiological‐pathological implications. The two other prize winners in this area of biologically active compounds, which are often referred to as eicosanoids, areSamuelsson's teacherSune Bergstömand the Brit
ISSN:0570-0833
DOI:10.1002/anie.198209021
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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4. |
CrTe3—A Novel Transition‐Metal Polytelluride |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 911-911
Kurt O. Klepp,
Herbert Ipser,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 2004. DOI:10.1002/anie.198220040
ISSN:0570-0833
DOI:10.1002/anie.198209111
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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5. |
Novel Metastable Germanium Modificationsallo‐Ge and 4H‐Ge from Li7Ge12 |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 912-913
Andreas Grüttner,
Reinhard Nesper,
Hans Georg von Schnering,
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ISSN:0570-0833
DOI:10.1002/anie.198209122
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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6. |
Cyclobutadienes or Acetylenes from (2‐Cyclopropen‐1‐yl)carbenes—A Question of Spin Multiplicity? |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 913-914
Philipp Eisenbarth,
Manfred Regitz,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 2016. DOI:10.1002/anie.198220160
ISSN:0570-0833
DOI:10.1002/anie.198209131
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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7. |
Catalyst Deactivation during Zirconocene‐ and Hafnocene‐Induced Ethylene Dimerization |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 914-915
Ulrich Dorf,
Klaus Engel,
Gerhard Erker,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 1984. DOI:10.1002/anie.198219840
ISSN:0570-0833
DOI:10.1002/anie.198209142
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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8. |
Steric and Electronic Control of Ligand Field Strength in Octahedral Co3+Spin‐Crossover Complexes |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 915-916
Werner Eberspach,
Nabil El Murr,
Wolfgang Kläui,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 1943. DOI:10.1002/anie.198219430
ISSN:0570-0833
DOI:10.1002/anie.198209151
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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9. |
Chloro(phenoxy)carbene—A Nucleophilic Carbene having Temperature‐Dependent Selectivity |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 916-917
Wolfgang Brück,
Heinz Dürr,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 2030. DOI:10.1002/anie.198220300
ISSN:0570-0833
DOI:10.1002/anie.198209161
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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10. |
1,2‐Dihydropentalene from 1,6‐Cyclooctadien‐3‐yne |
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Angewandte Chemie International Edition in English,
Volume 21,
Issue 12,
1982,
Page 917-918
Nobert Hanold,
Thomas Molz,
Herbert Meier,
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摘要:
AbstractThe complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 2050. DOI:10.1002/anie.198220500
ISSN:0570-0833
DOI:10.1002/anie.198209171
出版商:Hüthig&Wepf Verlag
年代:1982
数据来源: WILEY
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