The structures and properties of cis- and trans-MeCl2(NH3)(2), Me = Pd andPt complexes, in ground and excited states

Studies of structures, energetics, and charge distribution were performed f or ground and lowest excited electronic states of MeCl2(NH3)(2), Me = Pd an d Pt complexes. Despite the similarity of the Pd and Pt elements, the diffe rences in isomerization energies, ground-excited state separation energy, a nd electronic density distribution are significant. The Me-N and Me-Cl bond s possess a different nature with the Cl accepting and the NH3 group donati ng electrons to the central metal. The bonds are more polarized in Pt-based complexes. The electronic excitations involve mostly the metal atom, and a lthough they do not change the structure drastically, the excitations do, h owever, impact the charge distribution. Interaction energy decomposition fo r the ground state indicates that ammonia-metal interactions are dominated by the energy delocalization term. (C) 2001 John Wiley & Sons, Inc.