All gas phase geometry optimizations for the UBs (DS and DN) and UBP (DS-DN) have been performed using Gaussian 16 A.03 46 at the ωB97X-D 47 /6-311++G(d,p) level. Symmetry Adapted Perturbation Theory-DFT, SAPT(DFT) analysis has been done using the PSI4 1.2 software package . NCIPLOT has been employed to investigate the topology of non-covalent interactions between DS and DN. To predict the stability of the UBP in gas phase, we have calculated interaction energy (IEUBP) of the complexes by employing the following equation.