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- Ivanov, Alexander V., et al.
(author)
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Adducts of zinc and copper(II) morpholinedithiocarbamate complexes with morpholine of the composition [M(Mf)(MfDtC)(2)] and [M(Mf)(MfDtC)(2)]center dot Mf: Synthesis, thermal analysis, EPR, and CP/MAS C-13 NMR
- 2003
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In: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 48:3, s. 415-421
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Journal article (peer-reviewed)abstract
- The zinc and copper(II) morpholineditiohcarbamate complexes [M-2(MfDtc)(4)] and their adducts with morpholine [M(Mf)(MfDtc)(2)], including the solvated forms [M(Mf)(MfDtc)(2)] . Mf (M = Zn, Cu-63, Cu-65), have been synthesized and characterized by thermal analysis, EPR, and CP/MAS C-13 NMR data. Upon thermal destruction, the initial complexes, their adducts, and solvated forms lose weight in one, two, and three steps, respectively. The ultimate products of the thermal destruction of these complexes are zinc and copper sulfides. The range of the thermal destruction of the "dithiocarbamate part" is progressively shifted to lower temperatures in going from the initial binuclear complexes to their adducts and solvated forms. EPR shows that the geometry of the [CuS4N] chromophore in the [Cu(Mf)(MfDtc)(2)] adduct is close to square-pyramidal, the unpaired electron being predominantly localized in the metal 3d(x2-y2) AO. The outer-sphere solvation of the adduct is accompanied by structural reorganization at the molecular level. This reorganization involves a distortion of the [CuS4] base of the square-pyramidal polyhedron [CuS4N] toward a trigonal bipyramid. C-13 NMR shows that all of the zinc complexes under consideration are characterized by intramolecular nonequivalence of dithiocarbamate ligands. The N-15 NMR spectra adequately reflect the difference in the structural functions of pairs of dithiocarbamate ligands in [Zn-2(MfDtc)(4)].
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| 3. |
- Ivanov, Alexander V., et al.
(author)
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Adduct formation of the zinc morpholinedithiocarbamate complex with morpholine as studied by CP/MAS 15N NMR and single-crystal X-ray diffraction
- 2004
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In: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 49:12, s. 1863-1870
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Journal article (peer-reviewed)abstract
- The adduct of the zinc morpholineditiohcarbamate complex with morpholine [Zn(Mf)(MfDtc)2] and its solvated form [Zn(Mf)(MfDtc) 2]·Mf were studied by CP/MAS 15N NMR and single-crystal X-ray diffraction. These complexes are molecular, and the dithiocarbamate ligands therein are structurally nonequivalent. Solvation of the adduct aggravates this nonequivalence. The molecular and crystal structure of [Zn(Mf)(MfDtc)2]·Mf was determined by X-ray crystallography. The crystal structure of this compound has a system of ordered channels accommodating the outer-sphere morpholine molecules of solvation, which points to the formation of clathrate structures. The zinc coordination polyhedron [ZnS4N] is a somewhat distorted square pyramid with the four sulfur atoms at the base and the nitrogen atom at the apex. The square-pyramidal (SP) (97%) and trigonal-bipyramidal (TBP) (3%) contributions to the geometry of the zinc polyhedron were calculated. The 15N NMR signals were assigned to the structural positions of the nitrogen atoms in the molecular structure determined
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| 4. |
- Ivanov, Alexander V., et al.
(author)
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Adducts of zinc and copper(II) dialkyldithiocarbamate complexes with hexamethyleneimine: Synthesis, EPR, and CP/MAS 13C and 15N NMR
- 2004
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In: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 49:1, s. 95-101
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Journal article (peer-reviewed)abstract
- Powders of the zinc and copper(II) dimethyl- (MDtc), diethyl- (EDtc), and morpholinedilhiocarbamate (MfDtc) complexes quantitatively absorb hexamethyleneimine (Hmi) to produce the adducts [M{NH(CH2) 6}(S2CNR2)2] (M = Zn, Cu; R = CH3, C2H5; R2 = (CH 2)4O). The heterogeneous reaction of adduct formation is accompanied by dissociation of the binuclear molecules [M2(DtC) 4] of the initial dithiocarbamate complexes. Computer-aided simulation of EPR spectra for the copper(II) adducts shows that they are individual. The coordination polyhedron of copper in these compounds is intermediate between a trigonal bipyramid (TBP) and a square pyramid (SP). Based on EPR data, the TBP contribution is quantitatively estimated. 13C and 15N NMR shows that the MDtc and EDtc ligands in the adducts are structurally nonequivalent, whereas the MfDtc ligands are structurally equivalent. The 15N isotropic chemical shifts of the dithiocarbamate groups depend on alkyl substituents at the nitrogen atom.
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