Studies on Electronegativity by IR Ⅲ. The Relationship between the Electronegativity and the Vibrational Frequence of the Chemical Bond X-H in the Covalent Molecular Hydrides / 第三军医大学学报

ABSTRACT

In this work we studied systematically the correlation between the electrone-gativity, n/r or n*/r*, and the vibrational frequency of the chemical bond X-H, vX-H, in the covalent molecular hydrides. The results showed that there is good linear relationship between them.For the molecules of the type HnX-H, two cases were discussed.Case I, when the elements (X)are situated in the same group in the periodic table, the linear relation may be expressed in the following formala(1)Here K is a constant which varies with the number of valence electrons on the atom X.Case II , when the elements(X) are situated in the same period in the periodic table, the empirical equation can be written as follows(2)Here A and B are constants determined by the principle quantum number and the number of valence electrons in atom X respectively.For the molecules of the type YnX-H there is also a good linear relationship between vX-H and ∑n*/r*(Y), that is,vX-H?10-2=a + b∑n*/r*(Y)(3)Here a and b are constants determined by the position of the atom(X) in the periodic table.Using the above equations we have calculated the vibrational frequences, vX-H The values obtained are close to those obtained by other authors. Therefore, the results also confirm that the values of electronegativty calculated by our methods published in the previous papers(11) are trustworthy.In addition some characteristics of these equations were analyzed and discussed preliminarily.