Elemental Se and Te react with 4-tetrafluoropyridyl silver(I) to afford Se(C5F4N)2 and T...

Elemental Se and Te react with 4-tetrafluoropyridyl silver(I) to afford Se(C₅F₄N)₂ and Te(C₅F₄N)₂. Two independent bent molecules were found for each compound in the solid state with CiSeiC angles of 95.47(12)° and 96.16(13)°, and C–Te –C angles of 90.86(18)° and 91.73(18)°, respectively (Aboulkacem, S.; Naumann, D.; Tyrra, W.; Pantenburg, I. Organometallics , 2012 , 31 , 1559).

a. Explain why the angles are more acute for the Te compound relative to the Se compound.

b. These angles are approximately 0.8° (Se) and 2.0° (Te) more acute than those in the related pentafluorophenyl (C₆F₅) compounds. The greater compression of these angles in the 4-tetrafluoropyridyl compounds has been postulated on the basis of group electronegativity differences. Explain the logic associated with this hypothesis.