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

Article abstract of DOI:10.1134/S107032840704001X

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; R ₂ = (CH₂)₄O; R′ = C₄H ₉ 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. Nauka/Interperiodica 2007.

Full text of DOI:10.1134/S107032840704001X

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2007, Vol. 33, No. 4, pp. 233–243. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © A.V. Ivanov, A.S. Zaeva, E.V. Novikova, A.V. Gerasimenko, W. Forsling, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 4,
pp. 243−253.
Adducts of Zinc and Copper(II) Dialkyldithiocarbamate
Complexes with Dibutyl- and Diisobutylamines: Synthesis,
Structures, EPR and Solid-State Natural Abundance 13C
and 15N CP/MAS NMR Spectra
A. V. Ivanova, A. S. Zaevaa,b, E. V. Novikovaa,b, A. V. Gerasimenkoc, and W. Forslingd
a Institute of Geology and Nature Management, Amur Scientific Center, Far East Division,
Russian Academy of Sciences, Ryolochyi per. 1, Blagoveshchensk, Russia
b Blagoveshchensk State Pedagogical University, Blagoveshchensk, 675000 Russia
c Institute of Chemistry, Far East Division, Russian Academy of Sciences,
pr. Stoletiya Vladivostoka 159, Vladivostok, 690022 Russia
d Luléa University of Technology, S-971 87, Luléa, Sweden
Received April 3, 2006
Abstract—Crystalline adducts of zinc and copper(II) dithiocarbamate complexes with dibutyl- and diisobuty-
lamines of the general formula [M(NHR2 )(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 diisobu-
tylamine 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.
DOI: 10.1134/S107032840704001X
Dithiocarbamates of many metals tend to reversibly atomic positions in two crystallographically indepen-
dent conformers of [Zn{NH(i-C4H9)2}{S2CN(C2H5)2}2].
add organic N-, O-, S-, and P-donor bases to give het-
eroligand complexes generically called adducts.
Because their molecules are usually highly volatile in
vacuum, such adducts are of practical interest as tech-
nological precursors of metal-sulfide films with semi-
conducting and luminescent properties [1]. Earlier,
EXPERIMENTAL
The starting binuclear zinc dimethyl- and diethyl-
and morpholinedithiocarbamates of the general for-
conformational isomerism of adducts with both planar mula [Zn2(S2CNR2)4] (R = ëH3 and C2H5 or
R2 = (ëH2)4é) were prepared by reactions of Zn2+ with
[2–5] and nonplanar cyclic N-donor bases [6, 7] has
appropriate dithiocarbamate ions in aqueous solutions
[8]. The resulting bulky precipitates were washed by
decantation, filtered off, and dried in air.
(Dibutylamine)bis(dimethyldithiocarbamato)zinc
[Zn{NH(C4H9)2}{S2CN(CH3)2}2] (I), (dibutylami-
ne)bis(diethyldithiocarbamato)zinc [Zn{NH(C4H9)2}
been found in crystalline adducts of zinc and copper(II)
dithiocarbamates (Dtcs) with pyridine and morpholine.
In this study, we obtained adducts of zinc and cop-
per(II) dimethyl- and diethyldithiocarbamates and
their morpholine analogs with dibutyl- and diisobuty-
'
lamines of the general formula [M(NHR2 )(S2CNR2)2]
{S2CN(C2H5)2}2]
(II),
(dibutylamine)bis(morpho-
linedithiocarbamato)zinc
[Zn{NH(C4H9)2}
(M = Zn, 63Cu, and 65Cu; R = ëH3 and C2H5;
R2 = (ëH2)4é; R' = C4H9 and i−C4H9) and performed
their detailed characterization by EPR and solid-state
13C and 15N MAS NMR spectroscopy. We discovered
conformational isomerism in adducts with acyclic
N-donor bases. The signals in the 13C and 15N MAS
{S2CN(CH2)4é}2] (III), (diisobutylamine)bis(dime-
thyldithiocarbamato)zinc
[Zn{NH(i-C4H9)2}
[Zn{NH(i-C4H9)2}
{S2CN(CH3)2}2] (IV), and bis(diethyldithiocarbam-
ato)(diisobutylamine)zinc
{S2CN(C2H5)2}2] (V) were synthesized in two ways: (1)
by reactions of binuclear zinc complexes with dialky-
NMR spectra of the adducts were assigned to the lamines in toluene followed by room-temperature crys-
233

234
IVANOV et al.
tallization of adducts and (2) by quantitative absorption frequency meter. g Factors were calculated with refer-
of the dialkylamine vapor from the gas phase by pow- ence to DPPH. The error in the determination of g fac-
dered binuclear zinc complexes. The degrees of conver- tors was 0.002; the constants of the hyperfine structure
sion of the starting complexes into adducts were (HFS) are quoted in oersteds (Oe) to within 2%. EPR
checked by 13C NMR spectroscopy and gravimetry.
spectra were modeled at the MP2 level with the WIN-
EPR SimFonia program (Bruker Co. software, version
1.2). g Factors, HFS constants, resonance line widths,
and percent contributions from the Lorentz and Gauss
components to the line shape were variables in the
modeling.
For adducts I–V obtained by crystallization from
1
toluene, elemental analysis for zinc gave the following
results:
For ZnS4N3C14H31 (I), M = 435.07
13C and 15N MAS NMR spectra were recorded on a
CMX-360 pulse spectrometer (Chemagnetics Infinity)
operating at 90.52 and 36.48 MHz, respectively (super-
conducting magnet with Ç0 = 8.46 T; Fourier trans-
form). The 13C–1H and 15N–1H cross polarization tech-
anal. calcd. (wt %): Zn, 15.03.
Found, (wt %):
Zn, 15.03/15.22 (for the 64Zn/66Zn
nuclides).
For ZnS4N3C18H39 (II), M = 491.13
13
15
niques were used; C/15N and N–1H dipolar interac-
tions were suppressed via proton decoupling in a
magnetic field with the corresponding proton resonance
frequency [9]. Samples (~350 mg) of the adducts were
packed into ZrO2 rotors (7.5 mm in diameter). The spin-
ning frequences in 13C/15N MAS NMR experiments
were 5000/2800–3000(1) Hz, respectively. The num-
bers of scans were 400–2400/3080–7600. The proton
π/2 pulse durations were 4.5/5.0 µs. The 1H–13C/1H–15N
contact times were 2.0/1.25–2.5 ms; the excitation
pulses were spaced at 2.0/2.5 s.
anal. calcd. (wt %): Zn, 13.31.
Found, (wt %):
Zn, 13.10/13.04.
For ZnS4O2N3C18H35 (III) M = 519.14
anal. calcd. (wt %): Zn, 12.60.
Found, (wt %):
Zn, 12.53/12.64.
For ZnS4N3C14H31 (IV), M = 435.07
anal. calcd. (wt %): Zn, 15.03.
Found, (wt %):
Zn, 14.39/14.83.
For ZnS4N3C18H39 (V), M = 491.13
Isotropic 13C and 15N chemical shifts δ (ppm) are
referenced to a line of crystalline adamantane used as
the external standard (δ = 38.56 ppm relative to tetram-
ethylsilane [10]) and crystalline NH4Cl (δ 0 ppm;
−341 ppm on the absolute scale [11, 12]), respectively.
The width of the reference line at δ 38.56 ppm (2.6 Hz)
for crystalline adamantane was used to check the
homogeneity of the magnetic field. The δ values were
corrected for drift of the magnetic field strength during
the measurements (its frequency equivalents for the
13C/15N nuclei were 0.050/0.017 Hz/h). The chemical
shifts and the integrated intensity ratios for the overlap-
ping signals were additionally refined by fragment-by-
fragment mathematical modeling of the spectra with
consideration of the line positions and widths and the
contributions from the Lorentz and Gauss components
to the line shapes.
anal. calcd. (wt %): Zn, 13.31.
Found, (wt %):
Zn, 13.28/13.39.
Single crystals of V for X-ray diffraction analysis
were grown from a solution in toluene.
(Dibutylamine)bis(dimethyldithiocarbamato)cop-
per(II) [Cu{NH(C4H9)2}{S2CN(CH3)2}2] (VI), (dibu-
tylamine)bis(diethyldithiocarbamato)copper(II)
[Cu{NH(C4H9)2}{S2CN(C2H5)2}2] (VII), (dibu-
tylamine)bis(morpholinedithiocarboamato)cop-
per(II) [Cu{NH(C4H9)2}{S2CN(CH2)4é}2] (VIII),
(diisobutylamine)bis(dimethyldithiocarbamato)cop-
per(II) [Cu{NH(i-C4H9)2}{S2CN(CH3)2}2] (IX), and
bis(diethyldithiocarbamato)(diisobutylamine)cop-
per(II) [Cu{NH(i-C4H9)2}{S2CN(C2H5)2}2] (X) were
obtained as described for adducts I–V from isotope-
substituted cupric salts magnetically diluted with zinc
(Cu : Zn = 1 : 1000; Cu, 99.3(1) and 99.2(1) at % for
63Cu and 65Cu, respectively). This was done to
enhance the resolution of EPR spectra. The degrees of
conversion of the starting complexes into adducts
were checked by gravimetry and EPR spectroscopy.
All the adducts obtained were stored in sealed tubes.
X-ray diffraction analysis of complex V was per-
formed on a SMART 1000 CCD diffractometer (MoKα
radiation, graphite monochromator) for an edged single
crystal. Reflections were collected in the hemisphere
[13] (crystal–detector distance 50 mm, ω scan mode,
scan step 0.2°, frame exposure time 10 s). Absorption
correction was applied from equivalent reflections. The
structure was solved by the direct method and refined
by the least-squares method in the anisotropic approxi-
mation for non-hydrogen atoms. The hydrogen atoms
were located geometrically and refined in the rider
model. The collected data were edited and the unit cell
parameters were refined with the SMART and SAINT-
Plus programs [13]. All calculations for structure deter-
The EPR spectra of magnetically diluted complexes
VI–X were recorded on a 70-02 XD/1 radio spectrom-
eter (~9.5 GHz; MP SZ, Minsk) at ~295 K. The operat-
ing frequency was measured with a ChZ-46 microwave
1
Elemental analysis was carried out by high-resolution mass spec-
trometry with inductively coupled plasma (HR-ICP-MS) in the
medium-resolution range, ∆m/m ≈ 4500 (ELEMENT, Finnigan
MAT, Bremen, Germany).
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

ADDUCTS OF ZINC AND COPPER(II)
235
Table 1. Selected crystallographic parameters and a sum-
mary of data collection and refinement for [Zn{NH(i-
C4H9)2}{S2CN(C2H5)2}2] (V)
mination and refinement were performed with the
SHELXTL/PC programs [14]. Selected crystallo-
graphic parameters and a summary of data collection
and refinement are summarized in Table 1. Atomic
coordinates are listed in Table 2. Bond lengths and
angles are given in Table 3.
Parameter
Value
M
491.13
173(1)
T, K
λ, Å
RESULTS AND DISCUSSION
EPR spectra. A comparative analysis of the exper-
imental and model EPR spectra of magnetically diluted
isotope-substituted copper(II) adducts VI–X revealed
their spectral individualities, although they show a
number of signs in common (Figs. 1, 2; Table 4): triaxi-
al anisotropy of the g and ÄCu tensors (provided the ori-
entation with g3 ≈ 2.00), the presence of quartets of the
0.71073
Crystal system
Space group
a, Å
Monoclinic
P21/c
16.534(2)
26.691(3)
11.403(1)
91.540(2)
5030.4(9)
8
resolved HFS due to 63Cu or 65Cu nuclei (I = 3/2) in all
the three orientations, and the presence of an intense
peak of extra absorption (EA) in the high-field range
[15, 16] (the spectrum of complex IX shows two AA
peaks). This character of anisotropy suggests that the
coordination polyhedra of the copper atom (C.N. 5) are
intermediate between a tetragonal pyramid (TP) and a
trigonal bipyramid (TBP) and that the ground state of
the unpaired electron results from mixing of the
b, Å
c, Å
β, deg
V, Å3
Z
ρ
calcd, g/cm3
1.297
3dx
- and 3dz2 -Äé of copper(II) [17, 18].
2 – y2
µ, mm–1
1.317
Contributions from TP and TBP to the geometries of
the copper polyhedra were quantitatively estimated in
terms of a methodological approach involving the
F(000)
2096
parameter ∆ = AC1 u – A2Cu [19]. For some adducts, we
Crystal shape (size, mm)
θ scan range, deg
Prism (0.30 × 0.24 × 0.16)
3.78–28.03
have found a correlation between the parameter ∆ and
the contribution from TBP to the geometry of the cop-
per polyhedron. For instance, with an increase in that
contribution from 55 to 85%, the parameter ∆ linearly
decreases from 105 to 64 Oe.
Ranges of h, k, and l indices –21 ≤ h ≤ 21, –35 ≤ k ≤ 32,
–15 ≤ l ≤ 12
The copper(II) adducts obtained can be arranged in
Number of measured reflec-
30684
12007 (Rint = 0.0449)
8805
the following order of increasing contribution from tions
TBP: VIII, X, IX, VI, and VII with ∆ = 114, 89, 77, 42,
Number of independent re-
flections
and 26 Oe, respectively. Therefore, the contributions
from TBP are ꢀ 55% for VIII, > 60% for X, ~75% for
IX, and > 85% for VI and VII.
Number of reflections with
I > 2σ(I)
13C and 15N MAS NMR spectra. A comparison of
the 13C and 15N MAS NMR spectra of the starting binu-
clear zinc dithiocarbamates and adducts I–V revealed
that adduct formation is always accompanied by disso-
ciation of binuclear molecules. The individuality of
each complex was evident from their experimental
NMR spectra. The 13C NMR spectra of crystalline
adducts I–V (Fig. 3; Table 5) show signals for
=NC(S)S–fragments and signals for alkyl (alkoxy) sub-
stituents in the Dtc ligands and coordinated bases. The
range in which Dtc fragments resonate is most informa-
tive. In this range, the 13C NMR spectra of adducts
I−III exhibit two (1 : 1) signals (Table 5) for two struc-
turally nonequivalent Dtc fragments. For adducts I and
II, these signals are asymmetric 1 : 2 doublets arising
from a coupling of the 13C nucleus with the quadrupole
Refinement method
Full-matrix least squares on F2
Number of parameters re-
fined
491
GOOF
1.012
R factors for F2 > 2σ(F2)
R factors for all reflections
Extinction coefficient
R1 = 0.0372, wR2 = 0.0786
R1 = 0.0624, wR2 = 0.0879
not refined
Residual electron density
–0.359/0.616
(min/max), e/Å3
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

236
IVANOV et al.
Table 2. Atomic coordinates (×104) and isotropic equivalent thermal parameters Uequiv for complex [Zn{NH(i-
C4H9)2}{S2CN(C2H5)2}2]V
Atom
x
y
z
Uequiv, Å2 Atom
x
y
z
Uequiv, Å2
Zn(1) 1416.3(2) 6043.5(1) 4881.8(2) 0.02348(7) C(11)
Zn(2) 3661.4(2) 3752.9(1) 9688.2(2) 0.02324(7) C(12)
790(2)
–77(2)
6928(1)
6806(1)
7076(1)
6948(1)
7012(1)
7574(1)
7733(1)
7746(1)
4175(1)
4420(1)
4894(1)
4664(1)
4315(1)
3408(2) 0.0322(6)
3647(3) 0.0425(7)
4731(3) 0.0573(9)
2561(3) 0.069(1)
4259(2) 0.0285(5)
4375(2) 0.0336(6)
4110(3) 0.0478(8)
5582(3) 0.0532(8)
8185(2) 0.0201(5)
8029(2) 0.0318(6)
8715(3) 0.0433(7)
6481(2) 0.0288(5)
5433(2) 0.0399(7)
S(1)
S(2)
S(3)
S(4)
S(5)
S(6)
S(7)
S(8)
N(1)
N(2)
N(3)
N(4)
N(5)
N(6)
C(1)
C(2)
1438.8(3) 6449.5(2) 7157.1(5) 0.0290(1)
313.0(3) 5757.3(2) 5886.8(5) 0.0241(1)
2747.2(3) 5737.4(2) 4844.5(5) 0.0244(1)
1475.2(3) 5572.3(2) 3018.4(5) 0.0284(1)
2255.9(3) 3892.3(2) 9535.8(5) 0.0250(1)
3372.4(3) 4159.4(2) 7654.0(5) 0.0274(1)
4012.4(4) 3484.8(2) 11806.7(5) 0.0279(1)
4650.5(3) 4319.2(2) 10408.4(5) 0.0254(1)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
–378(2)
–602(2)
2170(1)
2233(2)
3095(2)
1999(2)
2413(1)
980(1)
25(1)
2955(1)
1344(1)
1810(1)
5246(1)
4161(1)
545(1)
6150(1)
5168(1)
6795(1)
4400(1)
4069(1)
3110(1)
6128(1)
5909(1)
6272(1)
6438(1)
6131(1)
5459(1)
4902(1)
5204(1)
5090(1)
4661(1)
7977(2)
2960(2)
4396(2)
7597(2)
12522(2)
8926(2)
7101(2)
7916(2)
7470(3)
9053(2)
9948(2)
3532(2)
1871(2)
784(2)
0.0243(4)
0.0244(4)
0.0228(4)
0.0234(4)
0.0224(4)
0.0227(4)
0.0220(5)
0.0293(5)
0.0386(6)
0.0331(6)
0.0435(7)
0.0216(5)
0.0290(5)
0.0378(6)
0.0308(6)
0.0401(7)
830(2)
1935(2)
1834(2)
4700(1)
5826(1)
6629(2)
5328(1)
5835(2)
3950(1)
3052(1)
2637(2)
2923(2)
5059(1)
5351(1)
5125(2)
6271(2)
3966(1) 11677(2) 0.0210(5)
4484(1) 12420(2) 0.0291(5)
4322(1) 11951(2) 0.0358(6)
3755(1) 13585(2) 0.0263(5)
3291(1) 13416(2) 0.0364(6)
–779(1)
C(3) –1422(2)
2615(1)
2517(1)
2556(1)
1992(1)
3152(1)
3529(1)
3376(1)
3569(1)
9436(2) 0.0282(5)
9484(2) 0.0311(6)
8282(3) 0.0468(8)
9999(3) 0.0481(8)
8871(2) 0.0265(5)
7974(2) 0.0272(5)
6725(2) 0.0475(7)
8133(3) 0.0415(7)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
204(2)
681(2)
2447(1)
2714(2)
2892(2)
3795(1)
3372(2)
4241(2)
C(10) 3875(2)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

ADDUCTS OF ZINC AND COPPER(II)
237
Table 3. Selected bond lengths, bond angles ω, and torsion angles ϕ in the conformers of complex [Zn{NH(i-
C4H9)2}{S2CN(C2H5)2}2]
Bond
d, Å
Bond
d, Å
Bond
Conformer A
d, Å
Bond
d, Å
Conformer A
Conformer B
Conformer B
Zn(1)–N(3)
Zn(1)–S(1)
Zn(1)–S(2)
Zn(1)–S(3)
Zn(1)–S(4)
S(1)–C(1)
S(2)–C(1)
S(3)–C(6)
S(4)–C(6)
N(1)–C(1)
N(2)–C(6)
N(1)–C(2)
N(1)–C(4)
C(2)–C(3)
2.084(2) Zn(2)–N(6)
2.8110(7) Zn(2)–S(7)
2.3101(6) Zn(2)–S(8)
2.3490(6) Zn(2)–S(5)
2.4733(7) Zn(2)–S(6)
1.710(2) S(7)–C(24)
1.736(2) S(8)–C(24)
1.732(2) S(5)–C(19)
1.722(2) S(6)–C(19)
1.336(3) N(5)–C(24)
1.328(3) N(4)–C(19)
1.477(3) N(5)–C(25)
1.471(3) N(5)–C(27)
1.516(3) C(25)–C(26)
2.104(2) C(4)–C(5)
2.5707(7) N(2)–C(7)
2.3582(7) N(2)–C(9)
2.3553(7) C(7)–C(8)
2.5937(7) C(9)–C(10)
1.723(2) N(3)–C(11)
1.727(2) N(3)–C(15)
1.741(2) C(11)–C(12)
1.713(2) C(12)–C(13)
1.332(3) C(12)–C(14)
1.329(3) C(15)–C(16)
1.472(3) C(16)–C(17)
1.477(3) C(16)–C(18)
1.507(3)
1.514(4) C(27)–C(28)
1.476(3) N(4)–C(22)
1.468(3) N(4)–C(20)
1.514(3) C(22)–C(23)
1.517(4) C(20)–C(21)
1.476(3) N(6)–C(33)
1.495(3) N(6)–C(29)
1.502(4) C(33)–C(34)
1.526(4) C(34)–C(36)
1.540(4) C(34)–C(35)
1.510(3) C(29)–C(30)
1.526(3) C(30)–C(31)
1.511(4) C(30)–C(32)
1.510(3)
1.474(3)
1.471(3)
1.521(4)
1.511(4)
1.493(3)
1.488(3)
1.521(3)
1.530(3)
1.519(4)
1.511(3)
1.520(4)
1.536(3)
Angle
ω, deg
Angle
ω, deg
Angle
ω, deg
Angle
ω, deg
N(3)Zn(1)S(1)
N(3)Zn(1)S(2)
N(3)Zn(1)S(3)
N(3)Zn(1)S(4)
S(2)Zn(1)S(1)
S(3)Zn(1)S(4)
S(1)Zn(1)S(4)
S(2)Zn(1)S(3)
S(1)Zn(1)S(3)
S(4)Zn(1)S(2)
C(1)S(1)Zn(1)
C(1)S(2)Zn(1)
C(6)S(3)Zn(1)
C(6)S(4)Zn(1)
S(1)C(1)S(2)
S(4)C(6)S(3)
C(1)N(1)C(4)
C(1)N(1)C(2)
C(4)N(1)C(2)
C(6)N(2)C(7)
C(6)N(2)C(9)
82.72(6) N(6)Zn(2)S(7)
114.19(5) N(6)Zn(2)S(8)
112.16(5) N(6)Zn(2)S(5)
105.35(6) N(6)Zn(2)S(6)
70.16(2) S(8)Zn(2)S(7)
75.46(2) S(5)Zn(2)S(6)
171.53(2) S(7)Zn(2)S(6)
130.28(2) S(8)Zn(2)S(5)
99.30(2) S(7)Zn(2)S(5)
107.93(2) S(6)Zn(2)S(8)
77.40(8) C(24)S(7)Zn(2)
92.71(8) C(24)S(8)Zn(2)
85.31(7) C(19)S(5)Zn(2)
81.70(8) C(19)S(6)Zn(2)
119.2(1) S(7)C(24)S(8)
117.5(1) S(6)C(19)S(5)
121.9(2) C(24)N(5)C(27)
122.8(2) C(24)N(5)C(25)
115.3(2) C(25)N(5)C(27)
122.3(2) C(19)N(4)C(22)
122.1(2) C(19)N(4)C(20)
94.60(6) C(9)N(2)C(7)
113.01(5) N(1)C(1)S(1)
119.73(5) N(1)C(1)S(2)
92.10(6) N(1)C(2)C(3)
73.39(2) N(1)C(4)C(5)
73.15(2) N(2)C(6)S(4)
171.24(2) N(2)C(6)S(3)
126.73(2) N(2)C(7)C(8)
108.10(2) N(2)C(9)C(10)
98.78(2) C(11)N(3)C(15)
81.07(8) C(11)N(3)Zn(1)
87.59(8) N(3)C(11)C(12)
87.88(7) C(11)C(12)C(13)
81.02(8) C(11)C(12)C(14)
117.6(1) C(13)C(12)C(14)
117.7(1) C(15)N(3)Zn(1)
121.5(2) N(3)C(15)C(16)
121.9(2) C(15)C(16)C(17)
116.5(2) C(15)C(16)C(18)
122.1(2) C(18)C(16)C(17)
122.8(2)
115.7(2) C(20)N(4)C(22)
121.5(2) N(5)C(24)S(7)
119.3(2) N(5)C(24)S(8)
111.1(2) N(5)C(25)C(26)
111.6(2) N(5)C(27)C(28)
122.2(2) N(4)C(19)S(6)
120.3(2) N(4)C(19)S(5)
112.3(2) N(4)C(22)C(23)
112.4(2) N(4)C(20)C(21)
112.2(2) C(29)N(6)C(33)
117.6(2) C(29)N(6)Zn(2)
112.7(2) N(6)C(33)C(34)
112.2(2) C(33)C(34)C(36)
108.7(3) C(33)C(34)C(35)
110.3(3) C(35)C(34)C(36)
110.7(1) C(33)N(6)Zn(2)
115.8(2) N(6)C(29)C(30)
108.8(2) C(29)C(30)C(31)
111.3(2) C(29)C(30)C(32)
111.0(2) C(31)C(30)C(32)
115.1(2)
121.8(2)
120.6(2)
113.2(2)
113.5(2)
121.4(2)
120.9(2)
111.7(2)
111.9(2)
109.1(2)
117.6(1)
114.3(2)
107.4(2)
112.3(2)
110.4(2)
110.9(1)
114.1(2)
112.1(2)
108.5(2)
110.1(2)
Angle
ϕ, deg
Angle
ϕ, deg
Angle
ϕ, deg
Angle
ϕ, deg
Zn(1)S(3)S(4)C(6) –176.8(1) Zn(2)S(7)S(8)C(24) –172.7(1) S(4)C(6)N(2)C(7)
Zn(1)S(1)S(2)C(1) –171.5(2) Zn(2)S(5)S(6)C(19) –173.7(1) S(4)C(6)N(2)C(9)
–2.8(3) S(6)C(19)N(4)C(22)
177.2(2) S(6)C(19)N(4)C(20) –180.0(2)
–2.5(3)
S(3)ë(6)Zn(1)S(4) 177.3(1) S(8)C(24)Zn(2)S(7) –173.9(1) S(1)Zn(1)N(3)C(11) –139.0(2) S(6)Zn(2)N(6)C(29) –138.7(2)
S(1)ë(1)Zn(1)S(2) 172.9(1) S(5)C(19)Zn(2)S(6) 174.7(1) S(1)Zn(1)N(3)C(15) 90.2(2) S(6)Zn(2)N(6)C(33) 94.8(1)
S(1)C(1)N(1)C(2) 175.1(2) S(7)C(24)N(5)C(25) –179.2(2) S(2)Zn(1)N(3)C(11) –74.6(2) S(5)Zn(2)N(6)C(29) –66.9(2)
S(1)C(1)N(1)C(4) –2.1(3) S(7)C(24)N(5)C(27)
S(2)C(1)N(1)C(2) –5.7(3) S(8)C(24)N(5)C(25)
4.2(3) S(2)Zn(1)N(3)C(15) 154.6(1) S(5)Zn(2)N(6)C(33) 166.5(1)
0.0(3) S(3)Zn(1)N(3)C(11) 123.9(2) S(8)Zn(2)N(6)C(29) 120.9(2)
S(2)C(1)N(1)C(4) 177.1(2) S(8)C(24)N(5)C(27) –176.6(2) S(3)Zn(1)N(3)C(15) –6.9(2) S(8)Zn(2)N(6)C(33) –5.7(2)
S(3)C(6)N(2)C(7) 176.8(2) S(5)C(19)N(4)C(22) 176.9(2) S(4)Zn(1)N(3)C(11) 43.6(2) S(7)Zn(2)N(6)C(29) 47.0(2)
S(3)C(6)N(2)C(9) –3.2(3) S(5)C(19)N(4)C(20) –0.6(3) S(4)Zn(1)N(3)C(15) –87.2(2) S(7)Zn(2)N(6)C(33) –79.6(1)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

238
IVANOV et al.
DPPH
H
80 Oe
‡
b
63
Fig. 1. (a) Experimental and (b) model EPR spectra of the adduct [ Cu{NH(C H ) }{S CN(CH ) } ] magnetically diluted with zinc(II).
4
9 2
2
3 2 2
DPPH
H
80 Oe
‡
b
63
Fig. 2. (a) Experimental and (b) model EPR spectra of the adduct [ Cu{NH(i-C H ) }{S CN(C H ) } ] magnetically diluted with zinc(II).
4
9 2
2
2 5 2 2
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ADDUCTS OF ZINC AND COPPER(II)
239
Table 4. EPR parameters of the adducts of copper(II) dialkyldithiocarbamates*
AC1 u , Oe
Complex
g1
g2
AC2 u , Oe
g3
AC3 u , Oe
[Cu{NH(C4H9)2}{S2CN(CH3)2}2] (VI)
[Cu{NH(C4H9)2}{S2CN(C2H5)2}2] (VII)
[Cu{NH(C4H9)2}{S2CN(CH2)4O}2] (VIII)
[Cu{NH(i-C4H9)2}{S2CN(CH3)2}2] (IX)
[Cu{NH(i-C4H9)2}{S2CN(C2H5)2}2] (X)
2.117
2.106
2.123
2.129
2.121
111/119
103/110
126/135
130/139
132/141
2.078
2.094
2.026
2.049
2.051
69/74
77/82
12/13
53/57
43/46
2.008
2.006
2.041
2.009
2.023
19/20
46/49
12/13
16/17
24/26
63
65
* The HFS constants are given for the Cu/ Cu nuclides.
15N nucleus (I = 1) under the given conditions of MAS
Molecular structure of adduct V. The unit cell of
includes eight [Zn{NH(i-
experiments [20, 21]. The exceptions are adducts IV adduct
V
and V; their 13C NMR spectra contain a singlet and a C4H9)2}{S2CN(C2H5)2}2] molecules. Four of them are
1 : 1 : 1 : 1 quartet (Figs. 3a, 3b). The foregoing spectral structurally nonequivalent with the other four (Fig. 5;
patterns partially correlate with 15N NMR spectra Table 3). In each molecule, the Zn atom in the chro-
(Table 5) showing 1 : 1 doublets (for I–III) and a 1 : 1 : mophore [ZnNS4] coordinates a diisobutylamine mole-
1 : 1 quartet (for V) in the range of Dtc resonance sig- cule and two Dtc ligands, showing C.N. 5. The zinc
nals (Fig. 4). In addition, the 15N NMR spectra contain polyhedron is intermediate between TP and TBP. In the
one (for I–IV) or two signals (for V) due to the coordi- equatorial plane of TBP, the zinc atom coordinates the
nated bases. Thus, the 13C and 15N MAS NMR data sug- N atom of diisobutylamine and two S atoms of the Dtc
gest that crystalline adducts I–IV exist as single mole- ligands (via shorter Zn–S bonds). The two other, more
cules, while [Zn{NH(i-C4H9)2}{S2CN(C2H5)2}2] (V) distant S atoms are in the axial positions. In [22], the
exists as two isomeric molecules. In all the adducts, the parameter τ = (α – β)/60 was proposed for quantitative
Dtc ligands are structurally nonequivalent. Structural characterization of the polyhedra in complexes of met-
differences between the isomeric molecules in adductV als with C.N. 5; α and β are the largest two SZnS angles
were revealed by X-ray diffraction analysis.
(α > β). For an idealized TP (C4v) τ is zero because
‡
b
δ, ppm
13
Fig. 3. C MAS NMR spectra of the crystalline adducts [Zn{NH(i-C H ) }(S CNR ) ] for R = (a) CH and (b) C H ; the number
4
9 2
2
2 2
3
2 5
of scans/spinning frequency (Hz) is (a) 1820/5000 and (b) 1520/5000.
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240
IVANOV et al.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

ADDUCTS OF ZINC AND COPPER(II)
241
c
‡
b
d
130
120
110
100
10
0
130
120
110
100
0
–10
δ, ppm
15
'
Fig. 4. N MAS NMR spectra of the adducts [Zn(NHR )(S CNR ) ] for R' = (a, b) C H and (c, d) i-ë ç and R = (a, c) CH
2
2 2
4
9
4
9
3
2
and (b, d) C H ; the number of scans/spinning frequency (Hz) is (a) 4000/3000, (b) 3080/3000, (c) 3620/3000, and (d) 7600/2800.
2
5
(‡)
(b)
C(17)
C(15)
C(32)
C(31)
C(14)
C(35)
C(29)
C(16)
C(11)
C(13)
C(36)
C(33)
C(18)
C(30)
C(12)
C(34)
N(6)
N(3)
C(28)
S(6)
C(23)
Zn(2)
S(7)
S(4)
Zn(1)
C(6)
C(3)
S(1)
C(1)
C(26)
S(8)
C(19)
C(24)
N(5)
C(27)
C(8)
N(4)
C(7)
N(2)
C(22)
S(5)
C(4)
C(25)
S(2)
S(3)
N(1)
C(2)
C(20)
C(9)
C(5)
C(21)
C(10)
Fig. 5. Molecular structures of the conformers (a) A and (b) B of [Zn{NH(i-C H ) }{S CN(C H ) } ] with atomic thermal dis-
4
9 2
2
2 5 2 2
placement ellipsoids (50% probability).
α = β. In a regular TBP (C3v), the axial SZnS angle (α) tances: 2.802/2.953 and 2.954/2.972 Å (Zn(1)) and
is 180°, while the equatorial angle (β) is 120°; i.e.,
τ = 1. Any distorted polyhedron is described by
0 < τ < 1. According to our calculations, the contribu-
tion from TBP to one molecule (with Zn(1)) is slightly
lower (68.8%) than to the other (with Zn(2), 74.2%).
2.864/2.951 and 2.877/2.955 Å (Zn(2)). The chelate
rings is not absolutely planar because of the folding
along the S–S bond: the dihedral angles between the
planes of the [ZnSS] and [CSS] fragments are 171.49°
and −176.75° (Zn(1)) and –172.68° and –173.69°
(Zn(2)). Such a configuration of the four-membered
chelate ring is favorable for the trans-annular effect to
appear. The N–C(S)S bonds are stronger than the
S,S'-Anisobidentate coordination of the Dtc ligands
(in all adducts, one Zn–S bond is substantially shorter
than the other) gives rise to small four-membered che-
late rings [ZnSSC] with fairly short Zn···C/S···S dis- N−CH2 bonds and reflect the contribution of double
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 33 No. 4 2007

242
IVANOV et al.
bonding to the formally single bond (because the higher the 15N chemical shifts and the lower the 13C
sp2-hybridized N atom undergoes partial sp3-hybridiza- chemical shifts for these atoms [4]:
tion). That is why the C2NC(S)S fragments are virtually
Bond
N(1)–C(1) N(5)–C(24) N(4)–C(19) N(2)–C(6)
planar, although the C(2) and C(27) atoms in two of
them slightly deviate from the plane (Table 3).
d, Å
1.336
129.8
205.3
1.332
130.4
204.5
1.329
133.8
203.1
1.328
134.2
202.7
δ
δ
15N, ppm
13C, ppm
The structural similarity of the adduct molecules
allows them to be classified as conformers, when a
polyatomic molecular system reaches equilibrium in
two or more configurations with close energies. Note
the essential distinctions between conformers Ä
(Zn(1)) and Ç (Zn(2)) (Table 3):
When assigning 15N NMR signals for coordinated
diisobutylamine molecules, the character (different
strengths) of their coordination should be taken into
account. Since nitrogen is more electronegative than
zinc, the electron density of the Zn–N bond will be
shifted to the N atom, thus increasing the shielding of
its nucleus. This effect will be more pronounced for the
stronger Zn–N bond. Thus, the 15N NMR signal at
lower δ (–2.6 ppm) should be assigned to the N(3) atom
of the more strongly bonded amine (in conformer A),
while the signal at δ = –0.6 ppm is due to the N(6) atom
in conformer B.
—the Zn–N bond in conformerA (2.084 Å) is stron-
ger than in conformer B (2.104 Å);
—conformer A contains the Dtc ligands with the
most (the S(1) and S(2) atoms) and least pronounced
anisobidentate character (the S(3) and S(4) atoms) of
coordination;
—the axial Zn–S bonds in the Zn(2) polyhedron are
virtually equal, while their lengths for Zn(1) differ by
0.34 Å and its polyhedron combines the strongest and
weakest Zn–Sax bonds;
ACKNOWLEDGMENTS
The authors are grateful to the research engineer
M. Ranheimer for her constant assistance and to the
Bruker Co. for free access to the WIN-EPR SimFonia
program.
This work was supported by the Russian Foundation
for Basic Research and the Far East Division of the
Russian Academy of Sciences (Program “Dal’nii Vos-
tok”, grant no. 06-03-96009) and the Presidium of the
Far East Division of the Russian Academy of Sciences
(grant no. 05-III-G-04-060 on Basic and Applied
Researches by Young Scientists, 2005).
—the contributions from TBP (TP) to the geometry
of the zinc polyhedron in conformers A and B are
68.8% (31.2%) and 74.2% (25.8%), respectively;
—the coordinated diisobutylamine molecules in
conformers A and B differ in spatial orientation, which
is quantitatively expressed in terms of the torsion
angles SZnNC (Table 3). The orientations of these mol-
ecules relative to the strongest equatorial bonds (Zn(1)–
S(2) and Zn(2)–S(5)) differ on average by ~10°.
The manifestation of conformational isomerism in
adduct V only can be explained by the steric effect of
two bulky alkyl substituents in diisobutylamine.
A.V. Ivanov acknowledges the financial support of
the Agricola Research Center at the Luléa University of
Technology (Sweden).
Assignment of NMR signals. Let us consider pos-
sible assignments of 13C and 15N NMR signals to the
atomic positions in the crystallographically indepen-
dent conformers of adduct V. The different N–C(S)S
bond lengths in four Dtc ligands indicate different con-
tributions of double bonding (or, what is the same thing,
different degrees of mixing of the sp2- with sp3-hybrid-
ization states of the N and C atoms) [4, 23]. The greater
contribution of the sp2-hybridization state will corre-
spond to the stronger bond. In terms of the mesomeric
effect, this causes the electron density to shift toward
the –C(S)S– fragment, thus increasing the charge δ+ on
the N atom. This can be schematically represented as
follows:
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