The change of a monodentate binding in the respective 8CN complexes to bidentate gives rise to 9CN complexes with (3+2+1+1+1+1), Yb 69CN-1 and (2+2+2+1+1+1), Yb 69CN-2 arrangements. The tridentate Yb-F distances for the Yb 69CN-1 complex in RTIL medium varies from 2.36-2.46 Å. Comparing the bidentate Yb-F distances between the two 9CN complexes, it is noticed that the variation is larger for Yb 69CN-2, whereas for monodentate binding, the reverse trend i.e., larger variation for Yb 69CN-1 is observed. The 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - value of the Yb 69CN-2 complex is found to be greater (-367.4 kcal/mol) than the Yb 69CN-1 complex (-362.7 kcal/mol). In the case of 10CN complex, we are able to optimize one complex, Yb 610CN with (2+2+2+2+1+1) arrangements of PF6 -anions. The noticeable thing is here the variation of the bidentate Yb-F distance is quite large, from 2.30 to 2.57 Å. This large variation may be to reduce the repulsion between ten directly bonded fluoride anions around the Yb(III) center. The 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - calculated for this complex is -365.1 kcal/mol. Similar to Yb-5-PF6 -, for Yb-6-PF6 -also, the Yb 68CN-2 complex has the second highest 𝐵𝐵𝐵𝐵 𝑃𝑃𝑃𝑃 6 - , although the difference with respect to the most stable one is only 0.6 kcal/mol.