Ab initio characterizations of molecular structures, conformation energies, and hydrogen-bonding properties for polyurethane hard segments

1993 ◽  
Vol 26 (22) ◽  
pp. 5924-5936 ◽  
Author(s):  
H. Sun
1987 ◽  
Vol 52 (1) ◽  
pp. 6-13 ◽  
Author(s):  
Petr Kyselka ◽  
Zdeněk Havlas ◽  
Ivo Sláma

The paper deals with the solvation of Li+, Be2+, Na+, Mg2+, and Al3+ ions in dimethyl sulphoxide, dimethylformamide, acetonitrile, and water. The ab initio quantum chemical method was used to calculate the solvation energies, molecular structures, and charge distributions for the complexes water···ion, acetonitrile···ion, dimethyl sulphoxide···ion, and dimethylformamide···ion. The interaction energies were corrected for the superposition error. Complete geometry optimization was performed for the complex water···ion. Some generalizations are made on the basis of the results obtained.


1986 ◽  
Vol 90 (21) ◽  
pp. 4941-4945 ◽  
Author(s):  
Georg W. Suter ◽  
Alan J. Kallir ◽  
Urs P. Wild ◽  
Tuan Vo-Dinh

2020 ◽  
Vol 56 (6) ◽  
pp. 944-947 ◽  
Author(s):  
Nikolaos Tsoureas ◽  
Akseli Mansikkamäki ◽  
Richard A. Layfield

The synthesis, molecular structures and bonding properties of two uranium(iv) cyclobutadienyl half-sandwich complexes and a doubly activated cyclobutadienyl sandwich complex are described.


2016 ◽  
Vol 3 (7) ◽  
pp. 1133-1141 ◽  
Author(s):  
Marta Feroci ◽  
Isabella Chiarotto ◽  
Francesca D'Anna ◽  
Fabrizio Gala ◽  
Renato Noto ◽  
...  

1967 ◽  
Vol 40 (4) ◽  
pp. 1105-1110 ◽  
Author(s):  
Stuart L. Cooper ◽  
Arthur V. Tobolsky

Abstract Viscoelastic behavior of linear segmented elastomers was examined. The unusual properties found in spandex systems are also observable in hydrocarbon block co-polymers, indicating that hydrogen bonding interactions are perhaps not essential. Low temperature properties of segmented systems are governed by the structural nature of the associated flexible segments, which determines the value of the major glass transition temperature (Tg). It appears that an association of the hard segments provides a broad temperature range of enhanced rubbery modulus. This occurs between the major Tg and a secondary high temperature transition.


2011 ◽  
Vol 975 (1-3) ◽  
pp. 106-110 ◽  
Author(s):  
Carolina Estarellas ◽  
Antonio Frontera ◽  
David Quiñonero ◽  
Pere M. Deyà

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