Nickel(IV) dithiocarbamato complexes of the [Ni(ndtc)3]X type: X-ray structure of [Ni(hmidtc)3][FeCl4]

Article abstract of DOI:10.1016/j.poly.2011.08.022

A series of fourteen octahedral nickel(IV) dithiocarbamato complexes of the general formula [Ni(ndtc)₃]X·yH₂O {ndtc stands for the appropriate dithiocarbamate anion, X stands for ClO₄^- (1-8; y = 0) or [FeCl₄]^- (9-14; y = 0 for 9-12, 1 for 13 and 0.5 for 14} was prepared by the oxidation of the corresponding nickel(II) complexes, i.e. [Ni(ndtc)₂], with NOClO₄ or FeCl ₃. The complexes, involving a high-valent Ni^IVS ₆ core, were characterized by elemental analysis (C, H, N, Cl and Ni), UV-Vis and FTIR spectroscopy, thermal analysis and magnetochemical and conductivity measurements. The X-ray structure of [Ni(hmidtc) ₃][FeCl₄] (9) was determined {it consists of covalently discrete complex [Ni(hmidtc)₃]⁺ cations and [FeCl ₄]^- anions} and this revealed slightly distorted octahedral and tetrahedral geometries within the complex cations, and anions, respectively. The Ni(IV) atom is six-coordinated by three bidentate S-donor hexamethyleneiminedithiocarbamate anions (hmidtc), with Ni-S bond lengths ranging from 2.2597(5) to 2.2652(5) , while the shortest Ni...Cl and Ni...Fe distances equal 4.1043(12), and 6.2862(6) , respectively. Moreover, the formal oxidation state of iron in [FeCl₄]^- as well as the coordination geometry in its vicinity was also proved by ⁵⁷Fe Moessbauer spectroscopy in the case of 9.