Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of chemical information and modeling 32 (1992), S. 693-699 
    ISSN: 1520-5142
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of chemical information and modeling 33 (1993), S. 805-811 
    ISSN: 1520-5142
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 93 (1996), S. 165-176 
    ISSN: 1432-2234
    Keywords: Group valence ; Functional groups ; Multicenter bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The quantum chemical definition of valence as a property of an atom in a molecule was generalized to functional groups in molecules. The new definition was applied to a series of functional groups in simple organic molecules. The results were found to be in agreement with expectation on the basis of classical valence rules. CH2, N2 and CO group valences in selected organic molecules are compared. Group valences for systems violating the classical valence rules are also briefly discussed with an emphasis on the role of multicenter bonding in the phenomenon of hyper- and subvalence. Finally, Si2 groups serve to probe the bulk character of small and medium silicon clusters.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 59 (1981), S. 629-637 
    ISSN: 1432-2234
    Keywords: Electronegativity ; Valence states ; CNDO
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A generalization of the original method introduced by Hinze and Jaffé for calculating the orbital electronegativities is proposed. This generalization is based on a new energy partitioning scheme within the framework of CNDO approximation and permits the orbital electronegativities to be calculated for atoms in actual valence states in which they occur in real molecules.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of computer aided molecular design 13 (1999), S. 259-270 
    ISSN: 1573-4951
    Keywords: log P ; molecular quantum similarity measures ; quantitative structure-properties relationships (QSPR) ; substituent effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Since the dawn of quantitative structure-properties relationships (QSPR), empirical parameters related to structural, electronic and hydrophobic molecular properties have been used as molecular descriptors to determine such relationships. Among all these parameters, Hammett σ constants and the logarithm of the octanol- water partition coefficient, log P, have been massively employed in QSPR studies. In the present paper, a new molecular descriptor, based on quantum similarity measures (QSM), is proposed as a general substitute of these empirical parameters. This work continues previous analyses related to the use of QSM to QSPR, introducing molecular quantum self-similarity measures (MQS-SM) as a single working parameter in some cases. The use of MQS-SM as a molecular descriptor is first confirmed from the correlation with the aforementioned empirical parameters. The Hammett equation has been examined using MQS-SM for a series of substituted carboxylic acids. Then, for a series of aliphatic alcohols and acetic acid esters, log P values have been correlated with the self-similarity measure between density functions in water and octanol of a given molecule. And finally, some examples and applications of MQS-SM to determine QSAR are presented. In all studied cases MQS-SM appeared to be excellent molecular descriptors usable in general QSPR applications of chemical interest.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical chemistry 20 (1996), S. 301-310 
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract The recently proposed topological similarity index was applied to the elucidation of the interesting phenomenon of pericyclic reactivity, the so-called torquoselectivity. It has been shown that the similarity approach is indeed able to provide a simple and consistent explanation of this phenomenon even in nontrivial cases of counter-intuitive contrasteric control.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical chemistry 23 (1998), S. 85-103 
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract The Fermi holes are presented as a new means of analysis and visualisation of molecular structure. Based on these quantities it is possible to get clear and highly visual insight into the structure of molecular fragments (functional groups) even in molecules with complex bonding patterns like multicenter bonding, hypervalence, etc. In addition to allowing the detection and localization of multicenter bonding, the new approach also brings some new interesting possibilities for the quantitative evaluation of molecular similarity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Theoretica chimica acta 93 (1996), S. 165-176 
    ISSN: 0040-5744
    Keywords: Key words: Group valence ; Functional groups ; Multicenter bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract.  The quantum chemical definition of valence as a property of an atom in a molecule was generalized to functional groups in molecules. The new definition was applied to a series of functional groups in simple organic molecules. The results were found to be in agreement with expectation on the basis of classical valence rules. CH2, N2 and CO group valences in selected organic molecules are compared. Group valences for systems violating the classical valence rules are also briefly discussed with an emphasis on the role of multicenter bonding in the phenomenon of hyper- and subvalence. Finally, Si2 groups serve to probe the bulk character of small and medium silicon clusters.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical chemistry 21 (1997), S. 323-333 
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract A new method of visualisation of bonding in molecules is introduced. The method is based on the analysis of Fermi holes associated with conditional probabilities of finding one electron of the pair provided the second, reference, electron is localised in a certain molecular region. Based on this analysis it is possible to get a clear and highly visual insight into the structure of molecular fragments (functional groups) in molecules. In addition to this visualisation, the new approach opens the possibility of the new definition of atomic and group valence and, also, can be applied as a new means of the quantitative characterisation of similarity of structural fragments in the series of related molecules.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of mathematical chemistry 19 (1996), S. 265-270 
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract The recently proposed similarity index was applied to the quantitative justification of the empirical Hammond postulate for a series of selected pericyclic reactions. In keeping with the expectations of the postulate the transition states were shown to be reactant-like for exothermic and product-like for endothermic reactions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...