Molecular modeling of the octacoordinated tetracarbonato-Nd(III), [Nd(CO_3)_4]^(5-), complex and its nonacoordinated fluoro- and aquo-adducts  

作　　者：S. P. Sinha Alfredo M. Simas Gustavo L. C. Moura 

机构地区：[1]Scientific Research & Development [2]Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco

出　　处：《Journal of Rare Earths》2010年第6期847-853,共7页稀土学报（英文版）

摘　　要：Theoretical investigation on the structures of the octacoordinated [Nd(CO3)4]5-and the nonacoordinated [Nd(CO3)4.OH2]5-complexes, using the SPARKLE parameters of the lanthanides within MOPAC, revealed that they possessed dodecahedral and square antiprismatic structures respectively with an average Nd-O distance of 0.249 nm. These structures and the Nd-O distances agreed well with those experimentally found in the crystal structures. Replacing the water molecule with a fluoride ion or a mondentatecarbonato ligand resulted in a nonacoordinated distorted square antiprismatic structures where the trans-carbonato groups were twisted. The corresponding decacoordinated structures with two fluoride ions or a bidentatecarbonato group, [Nd(CO3)4·F2]7-and [Nd(CO3)5]7-, were also investigated. In both cases considerable twisting of the transcarbonato groups was observed.Theoretical investigation on the structures of the octacoordinated [Nd(CO3)4]5-and the nonacoordinated [Nd(CO3)4.OH2]5-complexes, using the SPARKLE parameters of the lanthanides within MOPAC, revealed that they possessed dodecahedral and square antiprismatic structures respectively with an average Nd-O distance of 0.249 nm. These structures and the Nd-O distances agreed well with those experimentally found in the crystal structures. Replacing the water molecule with a fluoride ion or a mondentatecarbonato ligand resulted in a nonacoordinated distorted square antiprismatic structures where the trans-carbonato groups were twisted. The corresponding decacoordinated structures with two fluoride ions or a bidentatecarbonato group, [Nd(CO3)4·F2]7-and [Nd(CO3)5]7-, were also investigated. In both cases considerable twisting of the transcarbonato groups was observed.

关 键 词：LANTHANIDES theoretical molecular models octacoordination carbonato complexes ADDUCTS MOPAC SPARKLE rare earths 

分 类 号：O614.335[理学—无机化学]