Premium
Coordination Modes of Hydroxamates in Neptunium (V) Complexes in Aqueous Solution
Author(s) -
Dumpala Rama Mohana Rao,
Rawat Neetika,
Bhattacharya Arunasis,
Tomar Bhupendra Singh
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700031
Subject(s) - chemistry , neptunium , steric effects , substituent , ligand (biochemistry) , ring (chemistry) , aqueous solution , crystallography , density functional theory , oxygen atom , atom (system on chip) , binding energy , computational chemistry , stereochemistry , molecule , inorganic chemistry , actinide , atomic physics , organic chemistry , receptor , biochemistry , physics , computer science , embedded system
A theoretical study to understand molecular structures and coordination modes of neptunium complexes with three different substituent hydroxamates viz., acetohydroxamate (AHA), benzhydroxamate (BHA) and salicylhydroxamate (SHA) was carried out using density functional theory (DFT). The geometries for different complexes reported in literature M x L y H z (x:y:z) viz 1:1:1, 1:2:2 and 1:2:0 were optimized and interaction energies (ΔE) for complexation process were calculated to obtain the most probable structures of complexes. The ΔE value revealed, the complex stability order as NpO 2 + ‐SHA > NpO 2 ‐AHA > NpO 2 ‐BHA which is in agreement with the reported experimental data. Higher negative charge on AHA compared to BHA leads to its higher interaction with NpO 2 which in turn reflects in shorter Np‐O eq (ligand) bond distances. In 1:1:1 complex of NpO 2 ‐SHA, the binding mode involving ortho hydroxyl group and ‐NHO − oxygen atom (seven membered ring) shows most negative interaction energy.However, for binding of second ligand in 1:2:2 NpO 2 ‐SHA complex, steric effects dominate and the mode involving five membered ring through oxygen atoms of ‐CONHO − is most stable.