Structural Organization of Nickel(II), Zinc(II), and Copper(II) Complexes with Diisobutyldithiocarbamate: EPR, 13C and 15N CP/MAS NMR, and X-Ray Diffraction Studies

Abstract

Dithiocarbamate complexes of transition metals have found wide use in various areas of practical activity [1]. For coordination chemistry, dialkyldithiocarbamates are of interest as ligands with different structural functions (monodentate, terminal bidentate, bridging bidentate, and mixed), which allows their complexes to be structurally organized in a variety of types (mono-, bi-, tri-, and, in the general case, polynuclear). Mononuclear centrosymmetric nickel(II) complexes with dithiocarbamate ligands [Ni ( S 2 CNR 2 ) 2 ] [2-18] contain the terminal dithiocarbamate groups coordinated by nickel in a bidentate manner through two sulfur atoms to give small planar four-membered chelate rings [NiS 2 C] (R = CH 3 [2], C 2 H 5 [3-5], C 3 H 7 [6, 7], i -C 3 H 7 [8], C 4 H 9 [9, 10], i -C 4 H 9 [9, 11], and C 2 H 5 O [12] or R 2 = ( CH 2 ) 4 [13], ( CH 2 ) 5 [14], ( CH 2 ) 6 [7, 15, 16], C 6 H 5 and CH 3 CO [17], and CH 3 and C 6 H 5 [18]). In contrast to nickel, zinc forms binuclear molecular structures [Zn 2 ( S 2 CNR 2 ) 4 ] [19-31] (R = CH 3 [19, 20], C 2 H 5 [21-23], C 3 H 7 [24], i -C 3 H 7 [25], C 4 H 9 [26], and CH 2 CH = CH 2 [27] or R 2 = ( CH 2 ) 4 [28], ( CH 2 ) 6 [29] , CH 3 and C 2 H 5 , CH 3 and C 3 H 7 , CH 3 and i -C 3 H 7 , CH 3 and C 4 H 9 [30], and C 2 H 5 and cyclo -C 6 H 11 [31]), in which the dithiocarbamate ligands are structurally nonequivalent in pairs. Two of them, namely, terminal bidentate ligands, form four-membered chelate rings [ZnS 2 C], while the other two (bridging ligands) connect the adjacent Zn atoms. The resulting dimer includes an elongated nonplanar eight-membered chelate ring [Zn 2 S 4 C 2 ] in the chair [21-25, 27-31] or tub conformation [19,20,26]. The coordination polyhedron of the zinc atom is a distorted tetrahedron or a trigonal bipyramid composed of sulfur atoms. The only exception is the mononuclear dicyclohexyldithiocarbamate complex [Zn { S 2 CN ( c -C 6 H 11 ) 2 } 2 ] with a tetrahedral structure [31]. (The presence of the two bulky cycloalkyl substituents in the ligand makes it sterically impossible to form a binuclear molecular structure.) However, dithiocarbamate complexes containing ligands with long-chain alkyl substituents have been poorly studied to date, although they can be of the greatest practical interest (as molecular precursors of film metal sulfides) because the molecular volatility in a vacuum increases with a lengthening of the hydrocarbon chain of a substituent.The goal of this study was to obtain nickel(II), zinc(II), and copper(II) complexes with diisobutyl-and dibutyldithiocarbamate and compare their structural organizations.EXPERIMENTAL Nickel(II) and zinc(II) complexes with dibutyl-(BDtc) and diisobutyldithiocarbamate ( i -BDtc) I -III were obtained by reactions of aqueous solutions of NiCl 2 · 6 H 2 O and ZnCl 2 with the corresponding sodium dithioAbstract -The structures and spectroscopic properties of nickel(II), zinc(II), and copper(II) complexes with dibutyl-and diisobutyldithiocarbamate were studied by EPR and 13 C and 15 N CP/MAS NMR spe...

15N NMR Spectroscopy in Structural Analysis: An Update (2001 - 2005)

“…and [Zn(S 2 CNEt 2 ) (morpholine)].morpholine prepared by solvation of [Zn (S 2 CNEt 2 )L] with L1 [276]. The isomeric forms of nickel(II) and zinc(II) diisobutyldithiocarbamate were detected [278]. Analogously, 15 N CP/MAS NMR spectra were used to manifest the conformational isomerism in zinc diethyldithiocarbamate adducts with dialkylamines [277].…”

A pyridine adduct of bis(di-iso-butyldithiocarbamato-S,S′)cadmium(II): Multinuclear (13C, 15N, 113Cd) CP/MAS NMR spectroscopy, crystal and molecular structure, and thermal behaviour

“…(iso-C 4 H 9 ) 2 } 2 ] (M = Zn, Ni) N,N-di-iso-butyldithiocarbamate complexes of cadmium(II) [6], zinc(II) [11,41] and nickel(II) [41] revealed the ranges of 15 N chemical shifts for nitrogen sites in dithiocarbamate ligands with tridentate bridging structural function (less shielded): 140.2-145.2 ppm and for more shielded Nsites in the terminal chelating Dtc groups: 125.8-133.4 ppm. Based on these results, we suggest here that both structurally non-equivalent N,N-di-iso-butyldithiocarbamate ligands of adduct 1 play the same terminal chelating structural function (see Table 3).…”

Unprecedented isolation of a dinuclear tin (II) complex stabilized by pyridine‐2,6‐dimethanol: structure, DFT and in vitro screening of cytotoxic properties

“…Tin complexes have witnessed vast range of applications in various biological and industrial fields . Such compounds possess fascinating medicinal importance like antiparasite agents, in horticulture as bactericidal, acraricidal and fungicidal medium, anti‐HIV and antitumor agents .…”