M. Bortoluzzi et al. / Polyhedron 99 (2015) 141–146
145
(br, 1H, NH); 9.46–8.90, 8.35–8.21 ppm (arom CH). 13C{1H} NMR
2. Yellow solid, yield 0.170 g (41%). Anal. Calc. for C2H4Cl4O3W:
(CD3CN) d = 162.7 (C@O); 148.2, 145.2, 143.1, 128.7 ppm (arom).
C, 5.98; H, 1.00; Cl, 35.30. Found: C, 6.03; H, 0.96; Cl, 35.12%. IR
(solid state):
m .
= 1665vs (C@O), 1001vs (W@O) cmꢀ1 1H NMR
(CD2Cl2) d = 9.27 (s, 1 H, OH); 2.53 ppm (s, 3 H, CH3). 13C{1H}
NMR (CD2Cl2) d = 181.6 (CO); 21.5 ppm (CH3).
4.3. Reactions of WCl6 with RCO2H (R = CH3, CHCl2, CCl3, CBr3) in
1:2 M ratios. Identification of RC(O)Cl (R = CH3, CHCl2, CBr3),
WCl4(O2CCCl3)2, 4, and isolation of WOCl4(CH3CO2H), 2, and
WCl5(O2CCCl3), 3
3. Yellow solid, yield 0.250 g (60%). Anal. Calc. for C2Cl8O2W: C,
4.59; H, 0.00; Cl, 54.18. Found: C, 4.66; H, 0.03; Cl, 53.97%. IR (solid
state):
m .
= 1751vs (C@O) cmꢀ1
4.4. Reactions of WOCl4 with RCO2H (R = CHCl2, CCl3, CBr3) in 1:1 M
ratio. Solid state IR analyses
4.3.1. NMR analyses
WCl6 (0.35 mmol), CD2Cl2 (1.5 mL), and the appropriate car-
boxylic acid (0.70 mmol) were introduced into a Schlenk tube in
the order given. The mixture was stirred at room temperature for
a variable time. During this period, the system was purged with
argon in order to remove the released gas (HCl). Bubbling the latter
into an aqueous solution of AgNO3 determined the precipitation of
a white solid (AgCl). An aliquot of the final mixture was transferred
into an NMR tube and then analyzed by NMR spectroscopy.
IR analyses were performed on solid residues obtained with a
procedure similar to that described for WCl6/RCO2H, by allowing
WOCl4 (0.70 mmol) to react with the appropriate carboxylic acid
(0.70 mmol) in CH2Cl2 (ca. 10 mL). The final mixture was dried in
vacuo thus affording the residue for IR analysis.
(1) From WOCl4/CCl3CO2H. Light orange solid. IR (solid state):
= 1719vs, 1590w-m cmꢀ1
.
(1) From WCl6/CH3CO2H. Yellow solution, reaction time 4 h. 1H
NMR (CD2Cl2) d = 9.24 (s, OH, 2); 2.69 (s, CH3, CH3COCl),
2.50 ppm (s, CH3, 2). Ratio CH3COCl/2 = ca. 1:1.2. 13C{1H}
NMR (CD2Cl2) d = 181.9 (CO, 2); 171.2 (CO, CH3C(O)Cl);
33.9 (CH3, CH3C(O)Cl); 21.5 ppm (CH3, 2).
m
(2) From WOCl4/CBr3CO2H. Yellow-red solid. IR (solid state):
= 1721s, 1618m-sh, 1584s, 1355s, 1002s cmꢀ1
(3) From WOCl4/CHCl2CO2H. Yellow-brown solid. IR (solid
state):
= 1738w, 1701w, 1663s, 1622m, 1010s-br cmꢀ1
m
.
m
.
(2) From WCl6/CCl3CO2H. Yellow solution over yellow precipi-
tate, reaction time 96 h. 1H NMR (CD2Cl2) d = 10.2 ppm (br,
OH, CCl3CO2H). 13C{1H} NMR (CD2Cl2) d = 166.1 (CO,
CCl3CO2H); 163.7, 160.0 (CO); 88.7 (CCl3, CCl3CO2H), 88.6,
86.9 ppm (CCl3).
(3) From WCl6/CBr3CO2H. Red solution, reaction time 18 h.
13C{1H} NMR (CD2Cl2) d = 169.7, 169.5, 167.3, 160.3 (CO);
162.9 (CO, CBr3C(O)Cl); 34.6 (CBr3, CBr3C(O)Cl); 31.9, 30.4,
26.7 ppm (CBr3).
(4) From WCl6/CHCl2CO2H. Yellow solution, reaction time 4 h.
1H NMR (CD2Cl2) d = 6.25 (s, CH, CHCl2C(O)Cl), 6.21 ppm (s,
CH), OH not observed. 13C{1H} NMR (CD2Cl2) d = 169.6
(CO); 165.7 (CO, CHCl2C(O)Cl); 70.3 (CH, CHCl2C(O)Cl);
63.6 ppm (CH).
4.5. Reactions of WOCl4 with RC(O)Cl (R = CHCl2, CCl3, CBr3) in 1:1 M
ratio. Solid state IR analyses
4.5.1. General procedure
A suspension of PCl5 in CH2Cl2 (15 mL) was treated with RCO2H.
A colorless solution formed in one hour. Then WOCl4 was added to
the solution, and the resulting mixture was stirred for 18 h at room
temperature. Hence hexane (20 mL) was added, and the obtained
precipitate was isolated and dried in vacuo.
(1) From WOCl4/CCl3CO2H. Green solid. IR (solid state):
m
= 1753w, 1606m-br, 1006 m cmꢀ1
.
(2) From WOCl4/CBr3CO2H. Light green solid. IR (solid state):
= 1774vs, 1003s cmꢀ1
(3) From WOCl4/CHCl2CO2H. Light brown solid. IR (solid state):
= 1586 m, 1003s cmꢀ1
m
.
4.3.2. Solid state IR analyses
IR analyses were performed on solid residues which were
obtained with a procedure similar to that described for the prepa-
ration of the NMR samples, by allowing WCl6 (0.70 mmol) to react
with the appropriate carboxylic acid (1.4 mmol) in CH2Cl2 (ca.
10 mL). The final mixture was dried in vacuo thus affording the
residue for IR analysis.
m
.
4.6. X-ray crystallographic study
Crystal data and collection details for 1 are reported in Table 2.
The diffraction experiment was carried out on a Bruker APEX II
diffractometer equipped with a CCD detector and using Mo K
radiation (k = 0.71073 Å). Data were corrected for Lorentz polariza-
tion and absorption effects (empirical absorption correction SADABS
a
(1) From WCl6/CH3CO2H. Yellow oily solid. IR (solid state):
m
= 1666s (C@O, 2), 1627 m, 1001vs (W@O) cmꢀ1
.
)
(2) From WCl6/CCl3CO2H. Yellow solid. IR (solid state):
[21]. The structure was solved by direct method and refined by
full-matrix least-squares based on all data using F2 [22]. All non-
hydrogen atoms were refined with anisotropic displacement
parameters. H-atoms were placed in calculated positions and trea-
ted isotropically using the 1.2-fold Uiso value of the parent atom.
The N-bonded hydrogen atom H(1) was initially located in the
Fourier map but, then, it was refined with a riding model. Similar
U restraints were applied to the [C5H4NHC(O)Cl]+ cation [SIMU line
in SHELXL; s.u. 0.02].
m
= 1751s (C@O, 3), 1709vs-br (C@O, 4), 1669 m (C@O, 4),
1637w, 1621w, 1602w, 1087s-br (CꢀO) cmꢀ1
.
(3) From WCl6/CBr3CO2H. Orange sticky solid. IR (solid state):
m
= 1825m, 1768w, 1733m, 1724m-sh, 1689m, 1675w-m,
1584s, 1385s, 1002vs cmꢀ1
(4) From WCl6/CHCl2CO2H. Yellow sticky solid. IR (solid state):
= 1663w, 1611vs, 1378vs, 994vs cmꢀ1
.
m
.
4.3.3. Isolation of 2 and 3
A suspension of WCl6 (0.410 g, 1.03 mmol) in CH2Cl2 (15 mL)
was treated with CH3CO2H (0.12 mL, 2.10 mmol). The mixture
was stirred at room temperature for 18 h. The final mixture was
added of hexane (40 mL), thus affording a precipitate which was
isolated and dried in vacuo. A similar procedure led to the isolation
of 3, from WCl6 (0.320 g, 0.806 mmol) and CCl3CO2H (0.130 g,
0.796 mmol).
4.7. Computational studies
The computational geometry optimization of the complexes
was carried out without symmetry constrains using the hyper-
GGA functional M06 [23] in combination with the 6-31G(d,p) basis
sets on H, C, O and Cl atoms and the ECP-based polarized basis sets