摘要:

AbstractThe absorption spectra and the magnetic moments of Co2+, Ni2+, and Cu2+in alkali borate glasses of various compositions and in halide‐containing glasses have been explained from the point of view of the ligand field theory. Spectra and magnetic moments are highly dependent on the composition of the base glass; this must be ascribed to the change in the coordination of the transition‐metal ions. There are far‐reaching analogies with corresponding complexes in solution or in the crystalline

ISSN:0570-0833    

DOI:10.1002/anie.196600851

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractMadelung constants are simple numbers which depend on the type of structure investigated. They are needed for the calculation (using the Born‐Haber cycle) of lattice energies and enthalpies of formation of ionic compounds. Each Madelung constant is the sum of partial Madelung constants which represent the contributions of the individual ions to the total lattice energy. The partial Madelung constants depend on the ionic charge and, clearly though not stringently, on the coordination number. On the other hand, each Madelung constant can be represented by a sum of Madelung constants for related simple primitive AB structures. Surprisingly, these Madelung constants are numerically interrelated in a simple manner, and are related to the partial Madelung constants of interstitial sites. – Madelung constants of parameter‐dependent structures (e.g. of the rutile or anatase type) and their variations with the structure‐determining quantities are of particular interest. Madelung constants also yield information in the case of complex compounds and – surprisingly – of non‐metal compounds (e.g. XeF2, XeF

ISSN:0570-0833    

DOI:10.1002/anie.196600951

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractThe study of the structure of water and of aqueous solutions has recently received new impetus from the efforts at commercial desalineation of sea water and from developments in molecular biology. The current view that, apart from single molecules, water contains only one type of structural element, namely “flickering” network structures with tetrahedrally hydrogen‐bonded water molecules (two‐states model) is proving inadequate in the interpretation of new experimental data and in the calculation of thermodynamic functions. After a critical discussion of the basis of this model and of the concept of hydrogen bonds, a second kind of structural element, i.e. a third state, is suggested: small aggregates of molecules containing mainly non‐tetrahedral hydrogen bonds as well as some tetrahedral ones, and packed more densely than allowed by the lattice‐like structure. These aggregates – dimers to hexamers – can be regarded as the primary products of disruption of the network structures, and displace the latter as structural components in water with increasing temperature or concentration of solutes. This “combined” model allows a consistent interpretation of the properties of water and of the various effects of d

ISSN:0570-0833    

DOI:10.1002/anie.196601061

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601232

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601241

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601252

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601262

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601272

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601281

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196601291

出版商:Hüthig&Wepf Verlag    

年代:1966

数据来源: WILEY