5
0
STOLYAROV et al.
CF COOH and the crystalline salt precipitated when 2σ(I) and 0.0516, 0.1787 for all data for 274 parame-
3
using acetone.
ters.
Crystallographic data were deposited with the Cam-
Elemental analysis of the prepared compounds on
carbon, hydrogen, and nitrogen was carried out on an
EA3000 CHN analyzer (Eurovector, EU). The plati-
num content was determined gravimetrically after the
reduction of the complexes in a solution using hydrogen.
bridge Structural Database (CCDC no. 1029288). The
X-ray diffraction studies were carried out at the
Shared Facility Center of the Kurnakov Institute.
The organic products of alkane oxidation in reac-
The attenuated total reflection (ATR) IR spectra of the tions involving Pt(IV) trifluoroacetate complexes were
–1
prepared compounds in the range of 4000–500 cm
identified on an Agilent 6890-series chromatomass
were recorded on a Nikolet spectrophotometer spectrometer (USA) equipped with a mass-selective
(
France) equipped with an ATR attachment. The mass detector 5973 without prior isolation of the complexes
spectra of the complexes in solutions were obtained by from the mixture.
the electrospray ionization method using a Shimadzu
LCMS-2020 mass spectrometer (Shimadzu Scientific
Synthesis of Pt(IV) Perfluorocarboxylate Complexes
K
J.T. Baker, Phillipsburg, USA) immediately prior to hydroxoplatinate K [Pt(OH) ] (0.3753 g, 1 mmol) was
Instruments, Kyoto, Japan). Samples were dissolved
in acetonitrile dried over 4 Å molecular sieves
[Pt(CF
2
COO)
].
Crystalline
6
potassium
3
6
(
2
analysis or in glacial acetic acid (Sigma-Aldrich, ACS heated in a round-bottom flask with reflux contained
reagent) to achieve a concentration of ~0.1 mg/mL. trifluoroacetic acid (10 mL) for 15 min. The precipi-
Using a microsyringe, solutions of the complexes were tate of the hydroxo compounds completely dissolved
injected directly into the mass spectrometer. The tem- at boiling to form a yellow-orange solution. Most of
perature of the evaporator was 150°C; that of the con- trifluoroacetic acid was evaporated from the solution
necting line was 200°C. Nitrogen was used to spray the in a vacuum of 30 Torr at 60°C; remaining acid was
solution and dry it (1.5 and 10 L/min, respectively). removed from the resulting orange “oil” when dried in
The ionization voltage is 3.0 kV for positive ions and – a vacuum desiccator. A solid yellow substance is
3
.0 kV for negative ions. The range of mass spectra is obtained in vacuum over KOH, whose composition
2
00–2000 m/z. The Shimadzu LabSolutions software corresponds to the formula K [Pt(CF COO) ]. The
2
3
6
was used to analyze the obtained results.
yield was quantitative.
For K [Pt(CF COO) ] anal. calcd. (%): C, 15.14;
6
1
13
19
195
The H, C, F, and Pt NMR spectra were
2
3
recorded on a Bruker AVANCE III 500 MHz high- Pt, 20.51.
resolution spectrometer (Germany) with operating
frequencies of 500, 126, 471, and 108 MHz, respec-
tively. All spectra were recorded from solutions in
Found (%): C, 15.38; Pt, 20.39.
The ATR-IR spectrum is presented in Table 1; the
mass spectrum (electrospray ionization in MeCN) is
shown in Table 2.
CD CN at 22 ± 10°C. The chemical shift scale for
3
1
13
H and C NMR spectra was calibrated using solvent
1
H NMR (500 MHz, CD CN, 23°C, δ(CD HCN) =
1
3
2
signals (δ(CD HCN) = 1.94 ppm for H, δ(CD CN) =
2
13
3
13
1
.94, ppm): δ 10.72 (CF COOH). C NMR (126 MHz,
19
3
1
.32 ppm for C); that for F NMR spectra was calibrated
CD CN, 23°C, δ(CD CN) = 1.32, ppm): 162.8 (m;
3
3
using an internal standard (δ(C F ) = –162.2 ppm).
6
6
2
13
19
2
13
195
J( C, F) = 37.9 Hz, J( C, Pt) = 21.1 Hz;
X-ray diffraction was performed on a Bruker
2
13
19
COOPt); 159.6 (q; J( C, F) = 40.2 Hz; COOH);
SMART APEX II diffractometer at 173 K using MoK
1
13 19
α
1
(
16.4 (q; J( C, F) = 286.5 Hz; CF COOH); 112.9
3
radiation (graphite monochromator, λ = 0.71073 Å).
The data were corrected for absorption based on
equivalent reflections [9]. The structure was solved by
a direct method and refined by the full-matrix least-
1
13 19
3
13
195
m; J( C, F) = 289.5 Hz, J( C, Pt) = 68.1 Hz;
19
CF COOPt). F NMR (471 MHz, CD CN, 23°C,
3
3
4
19 195
δ(C F ) = –162.2): δ –72.05 (m; J( F, Pt) = 10.6 Hz;
6
6
195
squares method in the anisotropic approximation on CF COOPt); –74.55 (s; CF COOH).
Pt NMR
3
3
2
F for all non-hydrogen atoms [10]. All –CF groups (108 MHz, CD CN, 23°C): δ 3780.
3
3
are rotationally disordered in three or four positions
and were refined with the restrictions imposed on the
C–F and F···F distances. All hydrogen atoms were
located in calculated positions and refined using the
[
2
Pt(CF COO) ] . Platinum dioxide hydrate PtO ⋅
3
4 n
2
nH O (H Pt(OH) ) precipitated from an aqueous
2
6
solution was thoroughly washed with methyl acetate or
acetone and dried in vacuum over KOH. Platinum
dioxide hydrate PtO ⋅⋅ nH O without the excess
adsorbed water (0.280 g, 1 mmol) was heated in a
round-bottom flask with trifluoroacetic acid (10 mL)
for 15 min. The precipitate of the hydroxo compound
“
rider” model. Crystals C H F N O Pt (FW =
32 30 36 2 24
2
2
1
705.67) are trigonal, a = 15.0054(5) Å, c = 47.414(2) Å,
3
V = 9245.6(6) Å , space group R-3c, Z = 6, ρ =
3
–1
1.838 g/cm , F(000) = 4980, μ(MoK ) = 2.457 mm .
α
Number of reflections collected, 30187; unique, 2484; almost completely dissolved at boiling to form a yel-
R
= 0.0283. The final divergence factors are: R1 = low-orange solution; a small amount of the precipitate
int
0
.0440, wR2 = 0.1680 for 1997 reflections with I > was removed by filtration through a porous glass filter.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY
Vol. 64
No. 1
2019