摘要:

AbstractAlthough it has been appreciated for most of this century that the coordinating influence of many transition metal complexes extends beyond their covalently‐bonded first‐sphere ligands to non‐covalently bound chemical species in the so‐called second‐sphere, it is only recently that the fundamental importance of the phenomenon has been recognized and researched in its most general context. Rapid progress has been possible in this relatively new area of supramolecular chemistry by appealing to the symbiotic relationship that exists between X‐ray crystallographic investigations and synthetic work. The gamut of non‐covalent bonds, including electrostatic forces, hydrogen bonding, charge transfer, and van der Waals interactions are available for exploitation in choosing or designing suitable molecular receptors for particular transition metal complexes. Crown ethers are the synthetic macrocyclespar excellencefor forming adducts with neutral and cationic complexes carrying protic ligands (NH3, H2O, CH3CN, etc.) in their first coordination spheres. Anionic complexes with electron‐rich first‐sphere ligands (e.g. CN⊖) form adducts with polyammonium macrocyclic receptors. In both situations, hydrogen bonds and electrostatic interactions provide the dominant sources of supramolecular stabilization. Spectroscopic studies (UV, IR, and NMR) reveal that the structural integrity of the adducts is usually maintained in solution. The transition metal complexes can be organometallic as well as inorganic. In complexes supporting organic ligands, such as 1,5‐cyclooctadiene, norbornadiene, cyclopentadiene, 2,2′‐bipyridine, and trimethylphosphane, the opportunity exists to match their steric and electronic characteristics with appropriate binding sites in the molecular receptor. With these ligands, the weaker categories of non‐covalent bonding, e.g. charge transfer and van der Waals interactions, assume considerable importance. The phenomenon is also observable with naturally‐occurring receptors such as the cyclodextrins and polyether antibiotics. Moreover, it extends beyond the territory of transition metal complexes to main group complexes such as ammonia‐borane. As far as applications are concerned, it finds expression in areas as diverse as separation sc

ISSN:0570-0833    

DOI:10.1002/anie.198604873

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe cross‐coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon‐carbon bond. Because this mild, versatile reaction is tolerant of a wide variety of functional groups on either coupling partner, is stereospecific and regioselective, and gives high yields of product, it is ideal for use in the synthesis of elaborate organic molecules. When the coupling reaction is carried out in the presence of carbon monoxide, instead of a direct coupling, carbon monoxide insertion takes place, stitching the two coupling partners together and generating a ket

ISSN:0570-0833    

DOI:10.1002/anie.198605081

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractOrthophosphates of aluminum have been the subject of numerous studies since the middle of the nineteenth century. They have acquired importance in such diverse fields as the earth sciences, chemical engineering, and medicine. The chemical problems associated with this Al2O3P2O5H2O system mainly arise from the marked tendency to form polymeric aluminum orthophosphate complexes in solution; equilibrium is reached only with difficulty, and crystallization of single phases is the exception rather than the rule. However, the crystal structures of several aluminum orthophosphates (including minerals) have been elucidated, and it is now possible to give a systematic description of this class of compounds and the conditions necessary for their format

ISSN:0570-0833    

DOI:10.1002/anie.198605251

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe application of high‐pressure liquid chromatography (HPLC) to proteins has undergone a dramatic development in recent years. Nowadays its many variants expand the repertoire of high‐performance analysis methods available to the protein chemist, which, until now, have been dominated by electrophoretic techniques. The advent of gene technology has resulted in a renaissance of protein chemistry. The new analytical and preparative problems that have thereby emerged are often ideally solved by HPLC methods. HPLC has long since ceased to be solely a laboratory technique; HPLC systems are now being developed for the separation of proteins–particularly those of great pharmaceutical interest – on a 100‐g scale. The range of applications of analytical and preparative HPLC will be illustrated by two examples of pharmaceutical importance—insulin and in

ISSN:0570-0833    

DOI:10.1002/anie.198605351

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605531

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605541

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605551

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605561

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605571

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198605581

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY