1780
RODINA et al.
For TlS2PO2C12H22 (FW = 497.76) anal. calcd. (%): recorded at two spinning frequencies. Calculations
were performed with the Mathematica program [17].
S, 12.88; P, 6.22.
The X-ray diffraction experiment was carried out at
room temperature on a Bruker SMART 1000 CCD dif-
fractometer (MoKα radiation, graphite monochroma-
tor). Experimental intensity data were collected by a
routine procedure in a hemisphere; the crystal–detector
distance was 45 mm. Intensity data were corrected for
absorption based on the indices of the single crystal
facets. The structure was solved by direct methods and
refined by least-squares calculation in the anisotropic
approximation for non-hydrogen atoms. Hydrogen
atoms were introduced in the geometrically calculated
positions and refined as riding of their bonded carbon
atoms.
Data collection and editing, as well as the refine-
ment of unit cell parameters, were performed with the
SMART and SAINT Plus program packages [18]. All
calculations concerning structure solution and refine-
ment were performed with the SHELXTL/PC program
package [19]. Selected crystallographic data and refine-
ment results for Ib are summarized in Table 1; atomic
coordinates are presented in Table 2; and bond lengths
and angles are listed in Table 3.
Found (%): S, 12.98; P, 6.25.
Compounds Ia and Ib and the initial potassium
dicyclohexyl phosphorodithioate were characterized by
13C CP/MAS NMR:
[Tl{S2P(O-cyclo-C6H11)2}]n (Ia) (ppm): (1 : 2 : 2 : 1)
80.3, 72.9 (1 : 1, –OCH=); 35.2, 33.7, 31.5 (o-CH2–);
26.6, 25.9 (m-CH2–); 22.1 (p-CH2–).
[Tl2{S2P(O-cyclo-C6H11)2}2]n (Ib) (ppm): (1 : 2 : 3)
77.0, 76.5 (1 : 1, –OCH=); 36.4 (o-CH2–); 26.6
(m-CH2–); 27.6 (p-CH2–).
K{S2P(O-cyclo-C6H11)2} (ppm): (1 : 2 : 3) 79.9, 78.8,
78.1, 77.1 (1 : 1 : 1 : 1, –OCH=); 35.7, 35.2, 34.7, 33.9
(o-CH2–), 26.2 (m-, p-CH2–).
CP/MAS NMR spectra (13C, 31P) were recorded on a
Varian/Chemagnetics InfinityPlus CMX-360 spectrom-
eter operating at 90.52 and 145.73 MHz, respectively
(Ç0 = 8.46 T, superconducting magnet, Fourier trans-
form). Proton cross polarization was used for recording
the spectra. To suppress 13C–1H and 31P–1H dipole–
dipole interactions, CW decoupling at the proton reso-
nance frequency was used [10]. Samples of the com-
plexes (~350 mg) were placed in a zirconia rotor 7.5
RESULTS AND DISCUSSION
The CP/MAS 13C NMR spectra of thallium(I)
dicyclohexyl phosphorodithioate samples—precipi-
tated from an aqueous phase (Ia) and obtained by crys-
tallization from acetone (Ib)—show resonance signals
due to the Dtph ligands: the signals caused by the less
shielded carbon nuclei in the –OCH= groups and more
shielded carbon nuclei in the o-CH2–, m-CH2–, and
p-CH2– groups (Fig. 1). However, comparative analysis
of these spectra in the region of each of the above
groups demonstrates spectral difference between the
samples of Ia and Ib.
13
mm in diameter. The C/31P NMR spectra were mea-
sured under magic angle spinning conditions at spin-
ning frequencies of 2350–3150/2300–4500(1) Hz; the
number of scans was 2900–7900/128–1400; the proton
π/2 pulse width was 4.5/5.5–7.0 μs; the 1H–13C/1H–31P
mixing time was 2.0/2.0–3.0 ms; the repetition time
was 3.5/2.0–3.0 s. The isotropic 13C NMR chemical
shifts were measured in ppm from one of the compo-
nents of the spectrum of crystalline adamantane as an
external reference [11] (δ = 38.48 ppm from tetrameth-
ylsilane [12]); the 31P NMR chemical shifts were refer-
enced to aqueous 85% H3PO4 [13]. The homogeneity of
the magnetic field was monitored by measuring the
width of the reference signal of crystalline adamantane,
which was 2.6 Hz. The isotropic chemical shifts were
corrected for the magnetic field drift in the course of
experiments, which constituted 0.051/0.11 Hz/h on the
In the center of gravity of the 31P CP/MAS NMR
spectrum of Ia (Fig. 2, a and a'), there is one signal
(centerband) with the isotropic chemical shift (Table 4).
The recrystallization of the complex from acetone leads
to a new 31P CP/MAS NMR spectrum (Fig. 2, b and b').
Despite a considerable similarity of these spectra (Fig.
frequency scale for 13ë/31P nuclei. To refine the chemi- 2, a and a' and Fig. 2, b and b'), the isotropic chemical
cal shifts and integrated intensity ratios for overlapping
shift of the phosphorus sites of crystalline form Ib is
signals in 13C NMR spectra, spectra were simulated
noticeably higher than that for Ia (Table 4) while its
piecewise taking into account the line position and width is almost twice as large as that of the latter. Thus,
width, as well as the Lorentzian and Gaussian contribu-
tions to the line shape. The ê chemical shift anisot-
thallium(I) dicyclohexyl phosphorodithioate is able to
exist in two modifications. Comparison of the P iso-
31
31
ropy (δaniso = δzz – δiso) and the asymmetry parameter
tropic chemical shifts for Ia, Ib, and initial potassium
dicyclohexyl phosphorodithioate [20] allows us to state
that covalent bonding of the Dtph groups is accompa-
({η = (δyy – δxx)/(δzz – δiso)}) were calculated using χ2
plots [14], which were constructed based on the quan-
tification of the spinning sideband integrated intensity
nied by a decrease in δ(31ê) and, hence, by an increase
ratios [15, 16] in the full 31P CP/MAS NMR spectra in the degree of electron shielding of P nuclei. (The
31
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 54 No. 11 2009
Rodina
