The Cu K-edge extended X-ray absorption fine structure (EXAFS) studies in YBa(2)Cu(3)O(7-delta) and Y(0.4)Pr(0.6)Ba(2-x)Sr(x)Cu(3)O(7) with 0 less than or equal to x less than or equal to 1.25 have been carried out to examine the changes in near neighbour environment of Cu as a function of Sr doping. There is a sudden shift of apical oxygen 0(4) towards the CuO planes in compounds wherein superconductivity is restored. This contraction in the Cu(2)-O(4) bond length seems to weaken the Pr-O hybridization and thereby restoring superconductivity. Infrared absorption studies on these compounds also support this picture.
