Theoretical study on the PbIn (n=1-6) series molecules

Geometry optimizations and followed frequency calculations were performed for PbI (PbI+, PbI, and PbI-), PbI2 (PbI2+, PbI2, and PbI2-), PbI3 (PbI3+, PbI3, and PbI3-), PbI4 (PbI4, PbI4-, and PbI42-), PbI5 (PbI5, PbI5-, PbI52-, and PbI53-), and PbI6 (PbI6-, PbI62-, and PbI63-, and PbI64-) at the CCSD(T) level with aug-cc-pVDZ pseudopotentials and valence basis sets. Both PbI6- and PbI64- are unstable while both PbI62- and PbI63- are stable. All the optimized equilibrium structures can be described well with the single reference method such as DFT. The Pb-I bond length becomes larger while the Pb-I stretching frequencies become smaller as the structural unit has more electrons (such as from PbI4, PbI4-, to PbI42-). The unpaired electron is located on the Pb atom for PbI and PbI2- but is located on the I atoms for PbI2+, PbI3, PbI4-, PbI52-, and PbI63-. Harmonic vibrational frequencies plus adiabatic ionization potentials and electron affinities are reported. (C) 2016 Elsevier B.V. All rights reserved.