Synthesis and crystal structure of {(2-α-pyridylethyl)tris(phenyl) phosphonium}trichlorozinc(II)

Article abstract of DOI:10.1134/S1070328406110054

The structure of the complex {(2-α-pyridylethyl)tris(phenyl) phosphonium}trichlorozinc(II), which is an unexpected product of the reaction of the Zn²⁺ ion with coordinated 4,5-(2-pyridylethylene)dithio-1,3- dithiol-2-thione, is described. The reaction mechanism is studied by the ESI method of positive and negative ions. The crystals are monoclinic, space group P2₁/c, a= 16.129(3) A, b = 11.167(2) A, c = 14.874(3) A β = 91.77(3)°, Z = 4. The Zn(II) atom has a quasi-tetrahedral environment of three chloride ions and one phosphonium cation coordinated at the nitrogen atom of the pyridyl fragment. Nauka/Interperiodica 2006.

Full text of DOI:10.1134/S1070328406110054

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2006, Vol. 32, No. 11, pp. 796–800. © Pleiades Publishing, Inc., 2006.
Original Russian Text © V.A. Starodub, A.Yu. Stoesser, 2006, published in Koordinatsionnaya Khimiya, 2006, Vol. 32, No. 11, pp. 827–831.
Synthesis and Crystal Structure
of {(2-a-Pyridylethyl)tris(phenyl)phosphonium}trichlorozinc(II)
V. A. Starodub and A. Yu. Stoesser
Deparment of Chemistry, Kharkov State University, pl. Svobody 4, Kharkov, 61077 Ukraine
e-mail: starodub@univer.kharkov.ua
Received January 30, 2006
Abstract—The structure of the complex {(2-α-pyridylethyl)tris(phenyl)phosphonium}trichlorozinc(II), which is an
unexpected product of the reaction of the Zn2+ ion with coordinated 4,5-(2-pyridylethylene)dithio-1,3-dithiol-2-thione,
is described. The reaction mechanism is studied by the ESI method of positive and negative ions. The crystals are
monoclinic, space group P21/c, a= 16.129(3) Å, b = 11.167(2) Å, c = 14.874(3) Å, β = 91.77(3)°, Z = 4. The Zn(II)
atom has a quasi-tetrahedral environment of three chloride ions and one phosphonium cation coordinated at the nitro-
gen atom of the pyridyl fragment.
DOI: 10.1134/S1070328406110054
INTRODUCTION
solvents (Aldrich and Merck) were used as received.
Ligand II was synthesized according to a known proce-
dure [10]. Elemental analyses for carbon, hydrogen,
and nitrogen were carried out on a Vario EL instrument
The 1,3-dithiol-2-thione-4,5-dithiolate complexes
(C3S25– , Dmit) are widely used in modern chemistry in
the syntheses of related synthetic metals and supercon- (Elementar–Analysesysteme).
ductors, magnetically ordered structures, and materials
Synthesis of complex I. Compound II (50 mg,
of nonlinear optics [1–3]. In recent time, transition
metal complexes with 4,5-alkylenedithio-1,3-dithiol-2-
thiones, tetrakis(alkylthio)tetrathiofulvalenes, and
bis(alkylenedithiotetrathiofulvalenes) attract research-
ers' attention [4–7]. The method of Dmit functionaliza-
tion proposed in [8] is of special interest. The authors
synthesized alkylpyridyl derivatives of Dmit and dem-
onstrated that they can be used as polyfunctional
ligands. In particular, the [MX2L] complexes were
described, where M is Co, Ni, Cu, or Pd; X is Cl or Br;
L are alkylpyridyl derivatives of Dmit. The latter can be
coordinated at both the nitrogen atom of the pyridyl
ligand and the sulfur atoms of the thiol groups.
0.17 mmol) in MeCN (15 ml) was added with stirring
to [ZnCl2(PPh3)2] (110 mg) obtained by dissolving
ZnCl2 (0.16 mmol) in MeCN (20 ml) containing PPh3
(0.32 mmol). The reaction proceeds slowly and gives
two types of crystals, i.e., red and colorless. The latter
were suitable for X-ray diffraction analysis. The yield
of the colorless crystals was 30 mg (17%).
For C27H26Cl3ZnN2P (M = 581.24)
anal. calcd. (%):
Found, (%):
C 55.79 H 4.51, N 5.40.
C 55.73, H 4.42, N 5.40.
Note that the functionalization method proposed in
[8] gives linear derivatives of Dmit. Using the method
described in [9], we synthesized the products of cyclic
functionalization of Dmit [10].
In the present report, we describe the synthesis,
crystal structure, electrospray–ionization (ESI) data,
and IR spectra of a new complex [ZnCl3L](MeCN) (I)
(L+ is the 2-α-pyridylethyl-tris(phenyl)phosphonium
cation), which is an unexpected product in the reaction
ESI spectra were recorded on an ULTIMA FT-ICR
mass spectrometer (Ionspec) with an electrospray
source (Analytica). A solution of a mixture of crystals
in an isopropyl alcohol–acetone mixed solvent was
introduced into the instrument at a rate of 2 µl/min
through a high-quality steel capillary with an inner
diameter of 100 µm. The solvent was evaporated, and
ions got into the region with high vacuum created by a
of zinc dichloride with triphenylphosphine and two-step system of pumps (one turbomolecular pump
4,5-(2-pyridylethylene)dithio-1,3-dithiol-2-thione (II), and two cryopumps). The ions were transferred into a
whose structure has been determined in [10].
hexapole with a skimmer voltage of 20 V through a
glass capillary, whose nickel-plated ends were fed with
the potential difference from 390 to –140 V. Before
detection by the instrument, the ions were accumulated
EXPERIMENTAL
All procedures of the synthesis were carried out in the hexapole during ~1500 ms. The pressure in this
under dry nitrogen. Triphenylphosphine, ZnCl2, and all region was 1.33 × 10–4 Pa. The ions got through a qua-
796

SYNTHESIS AND CRYSTAL STRUCTURE
797
Table 1. Main crystallographic data and experimental de- Table 2. Selected bond lengths and bond angles in complex I
tails for the structure of complex I
Bond
d, Å
Bond
d, Å
Parameter
Value
Zn(1)–N(1)
Zn(1)–Cl(1)
Zn(1)–Cl(3)
Zn(1)–Cl(2)
P(1)–C(7)
2.098(3)
2.267(3)
2.243(3)
2.253(3)
1.806(5)
P(1)–C(8)
P(1)–C(14)
P(1)–C(20)
C(1)–C(6)
C(6)–C(7)
1.803(5)
1.787(5)
1.800(5)
1.502(6)
1.541(7)
FW
581.24
173 (2)
Recording temperature, K
Crystal system
Space group
a, Å
Monoclinic
P21/c
16.129(3)
11.167(2)
14.874(3)
91.77(3)
2677.72
4
b, Å
Angle
ω, deg
Angle
ω, deg
c, Å
Cl(1)Zn(1)Cl(2) 110.075(5) N(1)Zn(1)Cl(1) 111.152(10)
Cl(1)Zn(1)Cl(3) 109.642(5) N(1)Zn(1)Cl(2) 105.959(10)
Cl(2)Zn(1)Cl(3) 113.002(5) N(1)Zn(1)Cl(3) 106.934(10)
Zn(1)N(1)C(1) 125.926(3) P(1)C(7)C(6) 115.388(2)
Zn(1)N(1)C(2) 116.282(3) C(1)C(6)C(7) 111.525(4)
β, deg
V, Å3
Z
ρ(calcd.), g/cm3
µAg, mm–1
F(000)
1.442
1.72
1125
θ range, deg
Index range
3.25–63.66
–20 ≤ h ≤ 19
–14 ≤ k ≤ 14
–10 ≤ l ≤ 20
6302
geometrically and refined in the riding model with
Uiso = 1.2 Ueq of the corresponding C atom.
The main crystallographic data for compound I are
presented in Table 1. The selected bond lengths and
bond angles are given in Table 2.
Number of measured reflections
Crystallographic information on the structure of
compound I is deposited with the Cambridge Structure
Database (CSDB no. 294892).
Number of independent reflections 3347 (Rint = 0.0772)
Completeness with respect to θmax
,
91.7
%
RESULTS AND DISCUSSION
Number of refined parameters
293
Since the Zn2+ ion is classified as boundary Lewis
acids, ligand II can be coordinated, according to Pear-
son’s concept, to both the sulfur atoms and the nitrogen
atom to form the [ZnCl2(II)(PPh3)] complex. However,
according to X-ray diffraction data, the reaction of
ligand II with ZnCl2 and PPh3 affords colorless crystals
of complex I with the composition [ZnCl3(L)](MeCN).
R factors (I > 2σ(I))
R1 = 0.0692
wR2 = 0.2158
R factors (for all data)
∆ρmax, ∆ρmin, e Å–3
R1 = 0.1010
wR2 = 0.2370
1.86, –1.07
This complex contains coordinated L+ cation formed
due to the homolytic cleavage of ligand II. A similar
phenomenon was observed earlier [13]: the reaction of
ligand II with mercury(II) halides afforded the
[Hg(2PyDT-DTT)2] complex, where 2PyDT-DTT is
5-(1-pyridin-2-yl-vinylsulfanyl)-2-thioxo-[1.3]dithiol-4-
thiolate. This complex is formed by the decomposition
of binuclear complexes [HgX2(L')]2 with the elimina-
tion of hydrogen halide HX. In our case, the formation
drupole into an ICR cell (at 1.33 × 10–8 Pa), where they
were detected.
X-ray diffraction analysis. A STOE STADI4 dif-
fractometer with a planar detector and a graphite mono-
chromator (MoKα radiation, λ = 0.71073 Å) was used
for data collection.
The structure was solved by a direct method
(SHELXS97 [11]) and refined by the full-matrix least- of the L+ cation can be presented by the following
squares method for F2 in the anisotropic approximation
scheme, which also implies the heterolytic cleavage of
(SHELXL97 [12]). Hydrogen atoms were localized the C–S bonds to form the Dmit2– anion:
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 32 No. 11 2006

798
STARODUB, STOESSER
[ZnCl2(PPh3)2] + II
CH2
CH
ZnCl2(II) + 2PPh3
S
S
S
N
S
(II)
S
S
CH2
CH
S
2
S
N
S
S
Zn
Cl
Cl
1
ꢀ
Cl
Zn
Cl
S
S
Zn Cl
N
+
+
S
S
S
N
CH2–CH2Cl
S
S
S
(IV)
S
S
PPh3
CH2–CH2
ClH2C
CH2
Cl–
+ PPh3
+ [ZnCl2(PPh3)2]
+
N
CH
CH
2
2
ꢀ
3
ꢀ
N
N
2
Zn
Cl
Cl
Ph P
(L+Cl–)
(I)
3
Cl
–
Cl
Zn
Cl
S
S
Zn
S
N
4
ꢀ
S
+
S
S
N
C CH
+
S
H
S
S
S
(III)
S
S
S
S
S
5
ꢀ
Zn
2III + IV
Cl
Cl
Zn
S
S
S
Zn
Cl
Cl
S
S
S
S
S
(V)
S
S
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 32 No. 11 2006

SYNTHESIS AND CRYSTAL STRUCTURE
799
+
[Ph3P(CH2−CH2−2Py)]
I, %
100
369.3
[Zn4Cl8(II)(Ph3P−CH2−CH2−2Py)2]2+
938.0
90
80
70
60
50
40
30
20
940.0
939.0
936.0
937.0
941.0
[Zn(II)(PPh3)]2+
312.8
942.0
943.0
944.0
935.0
934.0
10
0
150
200
250
300
350
400
450
500
550
600
650
m/z
Fig. 1. ESI spectrum of positive ions in a mixture of crystals obtained in the synthesis of complex I.
This scheme agrees with the data of the ESI spectra. the pyridyl fragment. The Zn–N bond length in com-
The most intense peaks in the ESI spectra of positive
ions correspond to m/z values (Irel, %) of 312.8 (15),
369 (100), and 938 (100). The peak with m/z = 369 cor-
responds to cation L. The peak with m/z = 938 is
accompanied by lines with m/z = 934, 935, 937, 939,
940, 941, 942, and 943 with the intensity ratio corre-
sponding to the content of isotopes 64Zn, 66Zn, 68Zn, 32S
and 34S, 35Cl, 37Cl in the doubly charged ion
[Zn4Cl8(II)(Ph3–CH2–CH2–2Py)2]2+. The less intense
group of peaks with m/z = 312 (15%) corresponds to the
doubly charged ion [Zn(II)(PPh3)]2+ (Fig. 1).
plex I (2.100 Å) lies in a range characteristic of other
coordinated heterocyclic amines (average Zn–N
2.056 Å) [3]. The Zn–Cl bond (average 2.254 Å) is
[ZnCl(Dmit)]–
I, %
297.6
100
90
80
70
60
50
40
299.6
The ESI spectrum of negative ions (Fig. 2) exhibits
two series of peaks with m/z (Irel, %) at 296–304 (298–
100) and 460–468 (46–100). The first of them corre-
sponds to the [ZnCl(Dmit)] anion (III) formed by the
heterolytic dissociation of the C–S bonds in ligand II.
The second group of peaks corresponds to the
[Zn3Cl4(Dmit)3]2– doubly charged anion (V) containing
295.6
301.6
30
20
298.6
303.6
302.6
300.6
300
two coordinated C3S25– anions and coordinated iso-
296.6
296
10
0
trithionethiol molecule C3S5 (see scheme).
292
294
298
302
304
The molecular structure of complex I is shown in
Fig. 3. The Zn2+ ion exists in the center of a distorted
tetrahedron and is surrounded by three chloride ions
and one ligand L coordinated at the nitrogen atom of
m/z
Fig. 2. ESI spectrum of negative ions in a mixture of crys-
tals obtained in the synthesis of complex I.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 32 No. 11 2006

800
STARODUB, STOESSER
C(11)
C(10)
C(12)
C(4)
C(9)
C(13)
C(5)
C(1)
C(3)
C(8)
C(15)
C(16)
C(18)
P(1)
C(14)
C(7)
C(6)
C(17)
C(2)
C(19)
N(1)
C(20)
C(25)
C(21)
C(22)
Zn(1)
Cl(1)
Cl(2)
C(23)
C(24)
Cl(3)
Fig. 3. Molecular structure of complex I.
much shorter than the sum of the ionic radii of Zn2+ and
3. Cai-Ming Liu, De-Qing Zhang, Ying-Lin Song, et al.,
Eur. J. Inorg. Chem., 2002, no. 6, p. 1591.
Cl– (2.55 Å) [14] and occupies an intermediate position
4. Munakata, M., Wu, L.P., and Kuroda-Sowa, T., Bull.
Chem. Soc. Jpn., 1997, vol. 70, no. 8, p. 1727.
between the Zn–Cl bond length in gaseous ZnCl2
1
/
(2.05 Å) and in salt ZnCl · 1 H O (2.28 Å) built of
3
2
2
5. Dai, J., Munakata, M., Wu, L.P., et al., Inorg. Chim. Acta,
infinite (ZnCl3)nn– chains [14].
1997, vol. 258, no. 1, p. 65.
The reaction of the Zn2+ ion with coordinated
4,5-(2-pyridylethylene)-dithio-1,3-dithiol-2-thione we dis-
covered is unusual and occurs, probably, due to biden-
tate coordination of the latter, which facilitates cleavage
of its C–S bonds.
6. Dai, J., Munakata, M., Guo-Qing Bian, et al., Polyhe-
dron, 1998, vol. 17, no. 14, p. 2267.
7. Chunyang Jia, Deqing Zhang, Cai-Ming Liu, et al., New.
J. Chem., 2002, vol. 26, no. 4, p. 490.
8. Becher, J., Hazell, A., McKenzie, Ch.J., and Vester-
gaard, C., Polyhedron, 2000, vol. 19, no. 6, p. 665.
9. Neiland, O.Ya., Katsens, Ya.Ya., and Kreitsberga, Ya.N.,
ACKNOWLEDGMENTS
Zh. Org. Khim., 1989, vol. 25, no. 3, p. 658.
The authors are grateful to A. Rotenberger for X-ray
diffraction analysis, R. Burgert for familiarization and
help in recording the ESI spectra, and to D. Fenske for
providing possibility to perform experiments at the
Institute of Inorganic Chemistry of the Karlsruhe Uni-
versity (Germany).
10. Koshevaya, A.Yu. and Starodub, V.A., Khim.
Geterotsikl. Soedin., 2005, vol. 453, p. 321.
11. Sheldrick, G.M., SHELXS97. Program for the Solution
of Crystal Structures, Göttingen (Germany): Univ. of
Göttingen, 1997.
12. Sheldrick, G.M., SHELXL97. Program for the Refine-
ment of Crystal Structures,Göttingen (Germany): Univ.
of Göttingen, 1997.
REFERENCES
13. Hye Jin Nam, Ha-Jin Lee, Dong-Youn Noh, Polyhedron,
1. Cassoux, P., Coord. Chem. Rev., 1999, vols. 185–186,
2004, vol. 23, no. 1, p. 115.
p. 213.
2. Mulder, M.J.J., Haasnoot, J.G., Stufkens, D.J., et al., Eur. 14. Wells, A.F., Structural Inorganic Chemistry, Oxford:
J. Inorg. Chem., 2002, no. 7, p. 3083. Clarendon, 1986, vols. 2.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 32 No. 11 2006