Below is the table 4 with the data of 5-X-2-tellurophen carboxylic acids. needs a different explanation which is as follows: In benzene if we observe the substituent ortho to the functional group is in principle separated by a double bond again keeping in view of the statistical weight of the dynamic equilibrium of benzene or it simply needs a pair of π electrons (Scheme 4, H). In five membered ring system of 5-X-2-tellurophen carboxylic acid that lone π electron pair can be seen with tellurium. As tellurium has a maximum polarizability and bigger in size than either sulfur or oxygen the substituent effect more easily be transmitted from the substituent to the functional group via tellurium rather than π electron pair of the five membered ring as shown below in scheme 8.