IC-Lewis acid strengths application (2) Pyridine Compositions*

Yonghe Zhang

American Huilin Institute


       According to Mathew proposed [22]: IC Lewis acid strength of cations (Table 3) is relevant to Mathew’s compositions in the order:

 

Fe3+(2.531)>Fe2+(1.952)>Co2+(1.199)>Cu2+(0.622)>Cu+(0.295)

 

   When an organic molecule like electron donating pyridine adsorbs on the surface, cations get reduced due to charge transfer. Thus the easily reducible metal ions like Cu2+ undergo fast reduction to Cu+ and hence the stability of metal ion-pyridine complex decreases. From the acid strength of various cations it is clear that reduced Cu+ has very poor acidity. In other words, for a given ligand, corresponding stability constants of metal ions are in the order

 

Fe2+>Co2+>Cu2+

 

and hence the acidity of these ions also follow the same order, as shown earlier.” Table 3. shows that Pyridine compositions are relevant to Zhang’s scales of Lewis acid strengths and the ICP.

 

Tabl 3. Pyridine compositions in Zhang’s scales of Lewis acid strengths

 

Fe3+

Fe2+

Co2+

Cu2+

Cu+

Lic

2.531

1.952

1.199

0.622

0.295

Lz

1.311

0.39

0.356

0.177

-0.637

ICP

 

0.681

0.51

0.41

0.299

Sa

0.527

0.34

0.351

0.392

0.45

 

[*] Zhang, Y.Ionocovalency and Applications. 2. IC-Lewis acid strengthsJ. Am. huilin. Ins. 2011, 11, 1-10

[*] Zhang, Y. Ionocovalency, J. Am. huilin. Ins. 2011, 5, 1-11  

[*] Zhang, Y. Ionocovalency and Applications 1. Ionocovalency Model and Orbital Hybrid Scales. Int. J. Mol. Sci. 201011, 4381-4406 

 

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