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

The structures and spectroscopic properties of nickel(II), zinc(II), and copper(II) complexes with dibutyl- and diisobutyldithiocarbamate were studied by EPR and ¹³C and ¹⁵N CP/MAS NMR spectroscopy and X-ray diffraction analysis. According to the EPR data, copper(II) forms mononuclear [^63/65Cu{S₂CNR₂}₂] and heterobinuclear complexes [^63/65CuZn{S₂CNR₂}₄] under magnetic dilution conditions. The isomeric forms of nickel(II) and zinc(II) diisobutyldithiocarbamates were detected by ¹³C and ¹⁵N NMR spectroscopy. The crystalline zinc(II) diisobutyldithiocarbamate was found to have a unique structural organization with alternating mononuclear [Zn{S₂CN(i-C₄H₉)₂}₂] and binuclear molecular forms [Zn₂{ S₂CN(i-C₄H₉)₂}₄] in the 1 : 1 ratio.     

Adducts of zinc and copper(II) dialkyldithiocarbamate complexes with dialkylamines: Synthesis,EPR, and <Superscript>13</Superscript>C and <Superscript>15</Superscript>N CP/MAS NMR

Crystalline adducts of zinc and copper(II) dithiocarbamate (Dtc) complexes with dialkylamines [M(NHR′₂)(S₂CNR₂)₂] (M = Zn, ⁶³Cu, ⁶⁵Cu; R = CH₃, C₂H₅, or R₂ = (CH₂)₄O; R′ = C₂H₅, C₃H₇) have been preparatively isolated. The structures and spectral properties of the adducts have been studied by EPR and ¹³C and ¹⁵N MAS NMR. Chemisorption of bases on powders of dinuclear dithiocarbamates leads to their dissociation into monomeric adducts. Computer simulation demonstrates that the experimental EPR spectra of isotope-substituted copper(II) adducts have an individual character. The geometry of the copper polyhedra is intermediate between a trigonal bipyramid (TBP) and a tetragonal pyramid (TP). The TBP and TP contributions have been quantified based on EPR data. ¹³C and ¹⁵N MAS NMR data show that the Dtc ligands incorporated into the zinc adduct molecule are structurally nonequivalent. The dependence of the isotropic ¹⁵N chemical shifts of the Dtc groups on the alkyl substituents at the nitrogen atom is interpreted based on the concept of joint manifestation of the (+)inductive effect of the alkyl substituents and the mesomeric effect of the Dtc groups.     

Adducts of zinc and copper(II) dialkyldithiocarbamate complexes with dibutyl-and diisobutylamines: Synthesis,structures, EPR and solid-state natural abundance <Superscript>13</Superscript>C and <Superscript>15</Superscript>N CP/MAS NMR spectra

Crystalline adducts of zinc and copper(II) dithiocarbamate complexes with dibutyl-and diisobutylamines of the general formula [M(NHR′₂)(S₂CNR₂)₂] (M = Zn, ⁶³Cu, and ⁶⁵Cu; R = CH₃ and C₂H₅; R₂ = (CH₂)₄O; R′ = C₄H₉ and i-C₄H₉) were synthesized. Their structures and spectroscopic properties were studied by EPR and solid-state natural abundance ¹³C and ¹⁵N CP/MAS NMR spectroscopy. Experimental EPR data and computer-assisted modeling confirmed the individual character of copper(II) adducts. The geometries of the copper coordination polyhedra were found to be intermediate between a tetragonal pyramid and a trigonal bipyramid (TBP). The contributions from TBP to the geometries of the adducts obtained were calculated from the EPR data. According to the X-ray diffraction data, the adduct of zinc diethyldithiocarbamate with diisobutylamine exists in two isomeric forms. The ¹³C and ¹⁵N CP/MAS NMR signals were assigned to the atomic positions in two crystallographically independent conformer molecules.     

Structural organization and thermal properties of crystalline copper(II) <Emphasis Type="Italic">N,N</Emphasis>-<Emphasis Type="Italic">cyclo</Emphasis>-hexamethylenedithiocarbamate: A manifestation of coordination polymerism

The first representative of copper(II) dithiocarbamate complexes with an unusual type of structural organization is synthesized. According to the X-ray diffraction data, the layers of noncentrosymmetric mononuclear [Cu{S₂CN(CH₂)₆}₂] and centrosymmetric binuclear [Cu₂?ub;S₂CN (CH₂)₆?ub;₄] molecules alternate in the crystalline lattice of copper(II) N,N-cyclo-hexamethylenedithiocarbamate. The mononuclear and binuclear forms of the complex are observed in the 2: 1 ratio. The thermal properties of the synthesized compound are studied by thermogravimetry and differential scanning calorimetry. The final product of the thermal destruction of the complex is CuS.     

Structures of polynuclear thallium(I) and copper(II)-thallium(I) complexes with dialkyldithiocarbamates: 13C and 15N CP/MAS NMR, EPR, and X-ray diffraction studies

A comparative study of polynuclear thallium complexes with dialkyldithiocarbamates [Tl₂{S₂CNR₂}₂]_n (R = CH₃, i-C₃H₇, C₄H₉, and i-C₄H₉; R₂ = (CH₂)₆) was performed by solid-state ¹³C and ¹⁵N CP/MAS NMR spectroscopy. The dithiocarbamate groups were found to be structurally equivalent in the complexes studied. An increase in the positive inductive effect of alkyl substituents at the N atom increased ¹⁵N chemical shifts as a result of a combination of positive inductive effect of the alkyl substituents and the mesomeric effect of=NC(S)S-groups. The first representative of thallium(I) complexes with a cyclic dithiocarbamate ligand [Tl₂{S₂CN(CH₂)₆}₂]_n was obtained. Its molecular structure was determined from X-ray diffraction data. The β-form of the isotope-substituted complex [^63/65CuTl₂{S₂CN(CH₂)₆}₄] was obtained and examined by EPR spectroscopy. The EPR spectra were modeled at the second order of the perturbation theory. The spin density at the thallium atoms was calculated and its distribution over the AOs of thallium was determined.     

Extraction of metal ions (Fe<Superscript>3+</Superscript>, Co<Superscript>2+</Superscript>, Ni<Superscript>2+</Superscript>, Cu<Superscript>2+</Superscript> and Zn<Superscript>2+</Superscript>) using immobilized-polysiloxane iminobis(n-2-aminophenylacetamide) ligand system

A new insoluble solid functionalized ligand system bearing chelating ligand group of the general formula P-(CH₂)₃-N[CH₂CONH(C₆H₄)NH₂]₂, where P represents [Si–O] _n polysiloxane network, was prepared by the reaction of the immobilized diethyliminodiacetate polysiloxane ligand system, P-(CH₂)₃N(CH₂CO₂Et)₂ with 1,2-diaminobenzene in toluene. ¹³C CP-MAS NMR, XPS and FTIR results showed that most ethylacetate groups (–COOEt) were converted into the amide groups (–N–C=O). The new functionalized ligand system exhibits high capacity for extraction and removal of the metal ions (Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺) with efficiency of 95–97% after recovery from its primary metal complexes. This functionalized ligand system formed 1:1 metal to ligand complexes.     

Crystallographic report: Bis[bis(N,N‐dibenzyldithiocarbamato)cadmium(II)]

The centrosymmetric structure of {Cd[S₂CN(CH₂Ph)₂]₂}₂ features both bridging and chelating dithiocarbamate ligands so that a square pyramidal S₅ coordination geometry results. Copyright © 2004 John Wiley & Sons, Ltd.     

Adducts of zinc and copper(II) dimethyland diethyldithiocarbamates with piperidine: Synthesis, EPR, solid-state natural abundance 13C and 15N CP/MAS NMR and single-crystal X-ray diffraction studies

Crystalline adducts of zinc and copper(II) dimethyl-and diethyldithiocarbamates with piperidine (Pip) of the general formula [M{NH(CH₂)₅}(S₂CNR₂)₂] (M = Zn and ⁶³Cu; R = CH₃ and C₂H₅) were obtained. Their structures and spectroscopic characteristics were studied by X-ray diffraction analysis, EPR spectroscopy, and solid-state natural abundance ¹³C and ¹⁵N MAS NMR spectroscopy. The most substantial differences between the adducts of the formula [Zn{NH(CH₂)₅}(S₂CNR₂)₂] (R = CH₃ and C₂H₅) were found in the spatial orientations of the coordinated heterocycles and the geometries of the zinc polyhedra. The individual character of the EPR spectra of magnetically diluted isotope-substituted copper(II) adducts was determined by computerassisted modeling. The adducts of copper(II) and zinc dimethyldithiocarbamates proved to exist as two isomers. The coordination polyhedra of copper(II) and zinc are intermediate between a tetragonal pyramid (TP) and a trigonal bipyramid (TBP). The contributions from the TBP/TP components to the coordination polyhedra were quantitatively estimated from X-ray diffraction data. The ¹³C and ¹⁵N NMR signals were assigned to the positions of the atoms of the =NC(S)S^? groups in the resolved (according to X-ray diffraction data) molecular structures of the adducts.     

Crystallographic report: Bis(N,N‐dibenzyldithiocarbamato)mercury(II)

The monomeric structure of Hg[S₂CN(CH₂Ph)₂]₂, in which the mercury atom lies on a two fold axis that relates the unsymmetrically chelating dithiocarbamate ligands, features a severely distorted tetrahedral geometry. Copyright © 2004 John Wiley & Sons, Ltd.     

Crystallographic report: Bis(N,N‐dibenzyldithiocarbamato)zinc(II)

The structure of Zn[S₂CN(CH₂Ph)₂]₂ features, in contrast to many related analogues, a mononuclear species with two chelating dithiocarbamate ligands that form a distorted tetrahedral array around the zinc centre; the molecule has two‐fold symmetry. Copyright © 2004 John Wiley & Sons, Ltd.     

Crystallographic report: Bis[bis(N,N‐dibenzyldithiocarbamato)zinc(II)](4,4′‐bipyridine)

The centrosymmetric structure of {Zn[S₂CN(CH₂Ph)₂]₂}₂(4,4′‐bipy) features chelating dithiocarbamate ligands so that a trigonal bipyramidal NS₄ coordination geometry for zinc results. Copyright © 2003 John Wiley & Sons, Ltd.     

Copper(II) and cadmium(II) isothiocyanate coordination polymers with 4,4′‐bi‐1,2,4‐triazole

The coordination polymers catena‐poly[[[(4,4′‐bi‐1,2,4‐triazole‐κN¹)bis(thiocyanato‐κN)copper(II)]‐μ‐4,4′‐bi‐1,2,4‐triazole‐κ²N¹:N^1′] dihydrate], {[Cu(NCS)₂(C₄H₄N₆)₂]·2H₂O}_n, (I), and poly[tetrakis(μ‐4,4′‐bi‐1,2,4‐triazole‐κ²N¹:N^1′)bis(μ‐thiocyanato‐κ²N:S)tetrakis(thiocyanato‐κN)tricadmium(II)], [Cd₃(NCS)₆(C₄H₄N₆)₄]_n, (II), exhibit chain and two‐dimensional layer structures, respectively. The differentiation of the Lewis acidic nature of Cu^II and Cd^II has an influence on the coordination modes of the triazole and thiocyanate ligands, leading to topologically different polymeric motifs. In (I), copper ions are linked by bitriazole N:N′‐bridges into zigzag chains and the tetragonal–pyramidal CuN₅ environment is composed of two thiocyanate N atoms and three triazole N atoms [basal Cu—N = 1.9530 (18)–2.0390 (14) Å and apical Cu—N = 2.2637 (15) Å]. The structure of (II) contains two types of crystallographically unique Cd^II atoms. One type lies on an inversion center in a distorted CdN₆ octahedral environment, with bitriazole ligands in the equatorial plane and terminal isothiocyanate N atoms in the axial positions. The other type lies on a general position and forms centrosymmetric binuclear [Cd₂(μ‐NCS‐κ²N:S)₂(NCS)₂] units (tetragonal–pyramidal CdN₄S coordination). N:N′‐Bridging bitriazole ligands link the Cd centers into a flat (4,4)‐network.     

Adduct formation of cadmium(II) N,N-cyclo-hexamethylenedithiocarbamate, [Cd2{S2CN(CH2)6}4], with morpholine: Synthesis, molecular structure, and thermal behavior of a crystalline adduct cis-[Cd{NH(CH2)4O}2{S2CN(CH2)6}2]

The reaction of [Cd₂{S₂CN(CH₂)₆}₄] (I) with morpholine gives a crystalline adduct of cadmium N,N-cyclo-hexamethylenedithiocarbamate [Cd{NH(CH₂)₄O}₂{S₂CN(CH₂)₆}₂] (II), whose coordination sphere includes two molecules of the donor base. The structural organization and thermal behavior of II is studied by X-ray diffraction analysis and simultaneous thermal analysis in comparison with the original binuclear cadmium complex I. The central cadmium atom (coordination number 6) coordinates two morpholine molecules and two structurally equivalent S,S’-anisobidentate ligands HmDtc to form a chromophore [CdN₂S₄] with the structure of a distorted octahedron. The thermal destruction of II proceeds in two stages and includes consecutive steps of dissociation of the Cd-N bonds followed by the desorption of morpholine and thermolysis of the dithiocarbamate moiety of the adduct to form CdS as the final product. The structure of binuclear [Cd₂{S₂CN(CH₂)₆}₄] is refined for a correct refinement of the geometric characteristics of compounds I and II.     

Crystallographic report: Bis(pyrrolinedithiocarbamato)mercury(II)

The mononuclear structure of Hg(S₂CN(CH₂)₄)₂ has crystallographically imposed twofold symmetry and features chelating dithiocarbamate ligands that form asymmetric Hg? S bond distances leading to a heavily distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd.     

Complexes of podand-containing bis(dithiophosphonate) ligands with cobalt(II), nickel(II) and cadmium(II): recognition of CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript>

Reaction of the potassium salts of podand-containing bis(dithiophosphonate)s [PhO(4-C₆H₄)P(S)(SH)OCH₂CH₂]₂O (H ₂ L) with Co(II), Ni(II) and Cd(II) in aqueous EtOH leads to complexes of formulae M₂(L-S,S′)₂. The structural formulae of the compounds were deduced by physico-chemical and spectroscopic methods. It was established that complex Ni ₂ L ₂ recognizes CH₂Cl₂.     

Structure of binuclear platinum(III) acetamidate complexes in solutions as probed by <Superscript>195</Superscript>Pt, <Superscript>13</Superscript>C,and <Superscript>1</Superscript>H NMR spectroscopy

¹⁹⁵Pt, ¹H, and ¹³C NMR spectroscopy was used to study the structure of binuclear platinum(III) acetamidate complexes with 1,10-phenanthroline and 2,2′-bipyridine ligands [Pt₂(phen)₂(acam)₄](NO₃)₂ (1) and [Pt₂(bipy)₂(acam)₄](NO₃)₂ (2) in aqueous solutions. The ¹⁹⁵Pt NMR spectra of solutions of complexes 1 and 2 in D₂O exhibit two signals with satellites due to the ¹⁹⁵Pt–¹⁹⁵Pt spin-spin coupling (¹ J(Pt–Pt) ≈ 6345 Hz), whereas their ¹H and ¹³C NMR spectra contain four sets of signals for the protons and the carbon atoms of the heterocyclic and acetamidate ligands. The signals were assigned using the COSY, NOESY, and HSQC/ HMBC experiments and comparing the coordination shifts of the signals for the protons of heterocycles. These data allowed us to draw a conclusion that binuclear complexes 1 and 2 in solution have a head-to-head structure with nonequivalent platinum(III) atoms (coordination cores PtN₅ and PtN₃O₂), the axial-equatorial coordination of the bidentate heterocyclic molecules, and two bridging and two terminal acetamidate ligands.     

Bis(1,10‐phenanthroline)(thio­sulfato)­manganese(II) methanol solvate and catena‐poly­[[di­aqua(2,9‐di­methyl‐1,10‐phenanthroline)­manganese(II)]‐μ‐thio­sulfato]

The structure of bis(1,10‐phenanthroline‐κ²N,N′)(thio­sulfato‐κ²O:S)­manganese(II) methanol solvate, [Mn(S₂O₃)(C₁₂H₈N₂)₂]·CH₃OH, is made up of Mn²⁺ centers coordinated to two bidentate phenanthroline (phen) groups and an S,O‐chelating thio­sulfate anion, forming monomeric entities. The structure of catena‐poly­[[di­aqua(2,9‐di­methyl‐1,10‐phen­anthro­line‐κ²N,N′)­manganese(II)]‐μ‐thio­sulfato‐κ²O:S], [Mn(S₂O₃)(C₁₄H₁₂N₂)(H₂O)₂]_n, is polymeric, consisting of Mn(dmph)(H₂O)₂ units (dmph is 2,9‐di­methyl‐1,10‐phenanthroline) linked by thio­sulfate anions acting in an S,O‐chelating manner.     

A quantum chemical study of lead(II) thiocomplexes with mono- and bidentate ligands

Model Pb(II) thiocomplexes with mono- and bidentate ligands of the composition [Pb(L^1,2) _n ]²⁻ⁿ (L¹ is (SC₆H₅)⁻ (thiophenolate ion), L² is (S₂CN(CH₃)₂)⁻ (dithiocarbamate ion), n is the number of ligands of 2–6), which simulate fragments of the crystal structures of Pb(II) complex compounds with organic ligands, are studied within density functional theory. Geometric and energy parameters of model complexes with different coordination geometries of the Pb atom are determined and the stereochemical activity of the lone electron pair (LEP, E) of the Pb²⁺ ion is estimated in them. In the studied complexes, the highest Pb-S binding energy is found for the Pb atom surrounded by 2–4 ligands. The geometry of the Pb atom coordinated by S donor atoms can be described in terms of the valence shell electron pair repulsion (VSEPR) model with stereochemically active LEP. The coordination number (cn) of the Pb atom in the most energetically favorable complexes [Pb(SC₆H₅) _n ]²⁻ⁿ is (3+E) − (4+E), and in [Pb(S₂CN(CH₃)₂) _n ]²⁻ⁿ complexes, it is (4+E) and (6+E). Configurations with the mentioned cns are most often observed in the crystal structures of Pb(II) thiocomplex compounds.     

Synthesis, structure, and thermal properties of tallium(I) N,N- cyclo -pentamethylenedithiocarbamate [Tl2{S2CN(CH2)5}2] n : X-ray diffraction, 13C and 15N MAS NMR, and thermal analysis studies (An example of complicated structural organization)

Crystalline polynuclear thallium(I) N,N-cyclo-pentamethylenedithiocarbamate is synthesized by the preparative synthesis. According to the MAS NMR (¹³C, ¹⁵N) data, its composition includes four structurally nonequivalent dithiocarbamate ligands. According to the X-ray diffraction data, the complex synthesized is a remarkable example for the self-organization of the chemical system with a simple composition into an unusually complicated structure. The latter includes three types of the nonequivalent binuclear molecules [Tl₂{S₂CN(CH₂)₅}₂] (I) performing various structural functions. Two of them (centrosymmetric) alternate and participate in infinite polymeric chain building. The third structural function (noncentrosymmetric) is associated with the joining of the polymeric chains into two-dimensional layers. Structurally nonequivalent binuclear molecules I are shown to be related as conformers. The study of the thermal properties of the complex shows that Tl₂ S is the final thermal destruction product. Original Russian Text ? T.A. Rodina, A.V. Ivanov, O.A. Bredyuk, A.V. Gerasimenko, 2009, published in Koordinatsionnaya Khimiya, 2009, Vol. 35, No. 3, pp. 172–180.     

Synthesis,structure, and thermal properties of benzene-solvated forms of bis(dimethyldithiocarbamato)piperidinezinc and -copper(II)

Solvated adducts of zinc and copper(II) dimethyldithiocarbamate complexes with piperidine of the general formula [M{NH(CH₂)₅}{S₂CN(CH₃)₂}₂] · C₆H₆ (M = Zn (I), ⁶³Cu (II)) were isolated on a preparative scale. According to X-ray diffraction data, compound I has a clathrate type structure: the benzene molecules located between the coordinated piperidine rings of neighboring adduct molecules are held by hydrogen bonds. Thermal destruction of I studied by simultaneous thermal analysis includes the desorption steps of benzene solvate molecules and inner-sphere piperidine molecules and thermolysis of the “dithiocarbamate part” of the adduct to give ZnS as the final product. The triaxial anisotropy pattern of EPR parameters of the isotope-substituted magnetically diluted adduct II indicates that the geometry of the copper coordination polyhedron is intermediate between a tetragonal pyramid (TP) and trigonal bipyramid (TBP). It was shown solvation of the adduct [⁶³Cu{NH(CH₂)₅}{S₂CN(CH₃)₂}₂] resulting a considerable increase in the contribution of the TBP component.