Fern a´ ndez et al.
-
1
for C28
Found: C, 37.0; H, 2.6; N, 6.1%. IR (KBr, cm ): 1616 (vs), 1525
s), 1428 (s), 1409 (s), 1395 (s), 1147 (s), 1116 (vs), 1088 (vs),
H
24Cl
4
Mn
2
N
4
O
15 (908.2): C, 37.03; H, 2.63; N, 6.17.
H, 3.80; N, 9.98. Found: C, 51.2; H, 3.8; N, 9.9%. IR (KBr, cm ):
1723 (s), 1591 (s), 1479 (m), 1447 (m), 1420 (m), 1289 (s), 1150
(vs), 1117 (vs), 1091 (vs), 1019 (m), 782 (s), 742 (m), 624 (s).
-1
(
12
8
1
61 (m), 742 (m), 721 (s), 630 (m). Molar conductivity in MeCN,
[{Mn(bpy)(H O)} (µ-CH COO) (µ-O)](PF ) (9) and [{Mn-
(OH)(bpy)}(µ-PhCOO) (µ-O){Mn(NO )(bpy)}]‚H O (10) were
2
2
3
2
6 2
-
3
-1
2
-1
13
0
M: 287 Ω cm mol
{Mn(bpy)(H O)} (µ-RCOO)
ClCH COO (3) or CH COO (4). A solution of chloroacetic acid
0.15 g, 1.6 mmol) in MeCN, for compound 3, or glacial acetic
acid (1 mL, 1.6 mmol), for compound 4, was added to a solution
of Mn(NO ‚4H O (0.32 g, 1.28 mmol) in MeCN. Then, NBu
MnO (0.11 g, 0.32 mmol) dissolved in MeCN was added to the
.
2
3
2
[
2
2
2
(µ-O)](NO
3
)
2
with RCOO )
prepared as described in the literature. Anal. Calcd for C24
Mn (9): C, 31.39; N, 6.1; H, 3.29. Found: C, 31.3; N,
6.0; H, 3.3. Anal. Calcd for C34 10 (10): C, 52.52; N,
30 12
H F -
2 4 9 2
N O P
2
3
(
2 5
H29Mn N O
9.01; H, 3.76. Found: C, 52.4; N, 9.1; H, 3.6%.
)
3 2
2
4
-
Catalase Activity. An MeCN solution (20 mL) of binuclear Mn-
(III) complexes (1-4) (1 mM) was treated with 1 mL of H O (30
4
2
2
colorless solution, which became dark brown. Finally, a MeCN
solution of 2,2′-bipyridine (0.25 g, 1.6 mmol) was added, and the
resulting solution (90 mL) was filtered to eliminate any impurities.
The filtrate was left undisturbed for several hours, and the small
brown crystals formed were filtered off and dried in air. Recrys-
tallization of compound 3 (0.35 g) in MeCN (75 mL) with two
wt %). The brown color of the solution disappeared immediately,
and a large emission of O was observed. The intensity of the
2
evolved oxygen decreased after few minutes, and 15 min after the
beginning of the reaction, this evolution turned monotonic, and a
little brown and very fine solid was observed. After 3 h, the reaction
came to an end. The brown solid was filtered, and the yellow
solution was kept undisturbed at room temperature. After some
days, different Mn(II) compounds were obtained in each case.
For the nitrate complexes, 3 and 4, we also tested the effect of
drops of HNO
diffraction. Compound 3: yield 0.35 g (ca. 70%). Anal. Calcd for
Mn 13‚0.15 H O (787.96): C, 36.58; H, 3.11; N,
0.67; Cl, 9.00. Found: C, 36.4; H, 3.1; N, 10.8; Cl, 8.8%. IR
3
70% gave some brown crystals suitable for X-ray
C
24
H24Cl
2
2 6
N O
2
1
the addition of NaClO to the yellow solution obtained at the end
4
-
1
(KBr, cm ): 1602 (vs), 1449 (m), 1385 (vs), 1312 (m), 1261 (m),
of the reaction. Then, to these solutions 0.025 g of NaClO ‚H O
4
2
-
3
-1
773 (m), 728 (m). Molar conductivity in MeCN, 10 M: 116 Ω
(0.18 mmol) was added with stirring, and the resultant mixture was
kept undisturbed for some days until precipitation of the Mn(II)
compound.
2
-1
cm mol . Compound 4: yield 0.37 g (ca. 82%). Anal. Calcd for
13 (716.37): C, 40.24; H, 3.66; N, 11.73. Found:
24 2 6
C H26Mn N O
-
1
C, 40.4; H, 3.6; N, 11.9%. IR (KBr, cm ): 1602 (m), 1585 (s),
447 (m), 1384 (vs), 1309 (m), 1038 (m), 775 (m), 730 (m). Molar
The extent of the reaction was followed by measurement of the
oxygen volume evolved from the reaction of 5 mL of a 0.8 mM
acetonitrile solution of the binuclear Mn(III) complex, at room
temperature, with 0.3 mL of H O (8.8 M). Aliquots were taken
1
-
3
-1
2
-1
conductivity in MeCN, 10 M: 118 Ω cm mol
Mn(NO (bpy) ][Mn(NO )(bpy) (H O)]NO (5). 2,2′-Bipy-
ridine (bpy) (0.62 g, 4.0 mmol) in 30 mL of MeCN was added to
a solution of Mn(NO ‚4H O (0.51 g, 2 mmol) in 20 mL of the
.
[
3
)
2
2
3
2
2
3
2
2
after 1 min and transferred into an EPR tube (and frozen with liquid
N ) or injected into an ES-MS spectrometer. Conductivity measure-
2
3
)
2
2
same solvent. The solution turned yellow, and a pale yellow
precipitate was formed, filtered off, washed in ether, and dried in
air. From the mother liquor, or from a diluted solution of this
compound in EtOH or MeCN, it was possible to obtain some
crystals suitable for X-ray diffraction. Yield: 0.84 g (ca. 84%).
ments along the reaction were also carried out.
Physical Measurements. Analyses of C, H, N, and Cl were
carried out by the “Serveis Cient ´ı fico-T e` cnics” of the Universitat
de Barcelona. Infrared spectra (4000-400 cm-1) were recorded
from KBr pellets in a Nicolet Impact 400 FT-IR spectrometer.
Conductivity measurements were carried out with a CRISON
instrument Micro CN 2200, at 20 °C. Electrospray mass spectra
(ES-MS) were recorded on a Fisons VG Quattro spectrometer, by
the “Servei de Masses” of the Universitat de Barcelona. Magnetic
susceptibility measurements were performed on a MANICS-DSM8
susceptometer equipped with an Oxford Instruments liquid helium
cryostat, working down to 4.2 K, at the “Servei de Magnetoqu ´ı mica”
(Universitat de Barcelona). Pascal’s constants were used to estimate
Anal. Calcd for C40
N, 16.80. Found: C, 48.2; H, 3.4; N, 16.5%. IR (KBr, cm ): 1769
2 12
H34 Mn N O13 (1000.67): C, 48.01; H, 3.42;
-1
(
8
1
w), 1598 (s), 1578 (m), 1479 (m), 1440 (m), 1387 (vs), 1023 (s),
-
3
28 (m), 775 (s), 742 (m). Molar conductivity in MeCN, 10 M:
-
1
2
-1
33 Ω cm mol
.
[
Mn(nn) ](ClO ) with nn) bpy (6) or phen (7). Bidentate
3
4 2
amine (4 mmol; 0.62 g of 2,2′-bipyridine for compound 6, 0.72 g
of 1,10-phenantroline for compound 7) was added to an ethanolic
solution of 0.72 g (2 mmol) of Mn(ClO
The mixture turned yellow, and a yellow precipitate of [Mn(nn)
ClO was formed very quickly. Yield for 6: 1.37 g (ca. 94%).
Anal. Calcd for C30 MnN ‚0.5 H O (731.4): C, 49.25; H,
.42; N, 11.49. Found: C, 48.1; H, 3.4; N, 11.5%. IR (KBr, cm ):
591 (m), 1479 (m), 1460 (m), 1440 (s), 1420 (s), 1150 (vs),
117 (vs), 1085 (vs), 1019 (m), 782 (s), 762 (m), 742 (m), 624 (s).
4
)
2
‚6 H
2
O (20 mL of EtOH).
the diamagnetic corrections for each complex. The fits were
2
3
]-
performed by minimizing the function R ) ∑(ø
Mexp
- øMcalc) /
exp
2
(
4
)
2
∑(ø
) (for compounds 1, 2, and 4) or R ) ∑(ø ‚T - øM‚
Mexp
2
M
2
H24Cl
2
6
O
8
2
Tcalc) /∑(ø ‚T ) (for 3). EPR spectra were recorded at X-band
M
exp
-1
3
1
(9.4 GHz) frequencies with a Bruker ESP-300E spectrometer, at
the “Servei de Magnetoqu ´ı mica” of the Universitat de Barcelona.
X-ray Diffraction Data Collection and Refinement. A brown
crystal of [{Mn(bpy)(H O)} (µ-ClCH COO) (µ-O)] (ClO ) ‚1.9-
1
-
3
-1
2
-1
Molar conductivity in MeCN, 10 M: 299 Ω cm mol . Yield
for 7: 1.50 g (ca. 89%). Anal. Calcd for C36 MnN ‚3H
2
2
2
2
4 2
3
H24Cl
2
6
O
8
2
O
H O‚2CH CN (1) (0.60 × 0.25 × 0.12 mm ), a brown plate crystal
2
3
(
9
1
848.5): C, 50.94; H, 3.54; N, 9.90. Found: C, 51.1; H, 3.5; N,
of [{Mn(bpy)(H O)} (µ-ClCH COO) (µ-O)](NO ) ‚0.15H O (3)
2
2
2
2
3 2
2
.9%. IR (KBr, cm- ): 1627 (w), 1598 (w), 1525 (m), 1435 (s),
1
3
(0.50 × 0.20 × 0.10 mm ), a yellow needlelike crystal of [Mn-
(NO ) (bpy) ][Mn(NO )(bpy) (H O)]NO (5) (0.60 × 0.23 × 0.19
150 (vs),1117 (vs), 1091 (vs), 841 (s), 729 (s), 644 (s), 624 (s).
3
2
2
3
2
2
3
3
[Mn(bpy)
3
](ClO
4
)
2 6
‚0.5C H
4
-1,2-(COOEt)
2
‚0.5H
2
O (8). When
mm ), and a yellow block crystal of [Mn(bpy)
3
](ClO
4
2 6 4
) ‚0.5[C H -
3
the mother liquor of compound 6 was left undisturbed in open air,
orange needles of compound 8 were obtained. The same compound
1,2-(COOEt)
2
]‚0.5H
2
O (8) (0.35 × 0.35 × 0.17 mm ) were chosen
for X-ray diffraction experiments. The unit-cell and intensity data
were measured with a Stoe Image Plate Diffraction system
(compounds 1, 3, and 8) and a Stoe-Siemens AED2 four-circle
diffractometer (compound 5), using Mo KR graphite monochro-
mated radiation. The structures were solved by direct methods using
was also found by recrystallization of [Mn(bpy)
EtOH-H O mixture. X-ray diffraction showed that the crystalline
product was [Mn(bpy) ](ClO ‚0.5C -1,2-(COOEt) ‚0.5H O (8).
Anal. Calcd for C30 MnN ‚0.5C12 ‚0.5H O: C, 51.31;
3 4 2
](ClO ) (6) in an
2
3
)
4 2
H
6 4
2
2
H24Cl
2
O
6 8
H O
14 4
2
6686 Inorganic Chemistry, Vol. 43, No. 21, 2004