ELECTRONIC-STRUCTURES OF [LN(NO3)(X)(NCS)(Y)](N-) (LN-LA,ND,ER)

A localized INDO method was used to calculate the electronic structure s of a series of complex anions: [Ln(NO3)(x)(NCS)(y)](n-)(Ln = La, Nd, Er). Based on an analysis of the canonical molecular orbital (CMO) en ergy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the localized molecular o rbitals (LMOs) and the Mulliken bond orders, it is concluded that the stability of the complex anion increases with increasing coordination number. The sequence of orbital bonding ability of erbium is 5d >> 6p > 6s, and 4f orbitals do not participate in chemical bond formation. T he order of the M <-- O bond strength is Er <-- O > Nd <-- O similar t o La <-- O. The order of the M <-- N bond strength is Er <-- N similar to Nd <-- N.