J. Choi, et al.
Inorganica Chimica Acta 498 (2019) 119174
Very recently, we have reported one trinuclear coordination com-
plex, [(pmidip) Co (CH COO) ], based on deprotonated N-(2-pyr-
2.3. Competitive epoxidations of para-substituted styrenes and styrene for
Hammett plot with manganese catalyst 1
2
3
3
4
2
−
idylmethyl)iminodiisopropanol (pmidip ) [2a]. In the cobalt trimer,
two terminal Co(III) cations are connected to a central Co(II) cation
−
2
m-CPBA (3 × 10
mmol) was added to a mixture of styrene
2
−
−2
−2
through tetradentate pmidip
and acetato ligands, which leads to a
(2 × 10
= eCN, eCl, eCH
mmol), and solvent (MeCN/CH
mmol) and para(X)-substituted styrene (2 × 10
mmol, X
3
+
2+
3+
−3
trinuclear Co -Co -Co species. In this case, the oxidation state and
the structure were very dependent on the pmidip
3
, and eOCH
3
), manganese catalyst (2.8 × 10
2−
ligand and the
2
2
Cl (1/1), 1.0 mL). The mixture was
complex also showed efficient olefin epoxidations.
shaken for 5 min at ambient temperature. GC was used to measure the
amounts of styrenes before and after reactions. The relative reactivities
In order to explore the dependence of metal ion in the olefin
epoxidations by using the N -type ligand N-(2-pyridylmethyl)imi-
nodiisopropanol (H pmidip) and azide ion, we have prepared a new
2
O
2
were analyzed with the following equation: k
x
/k
are the initial and final concentration of styrene and
f
are the initial and final concentration of para-substituted
y f i f
= log(X /X )/log(Y /
2
Y
X
i
) where Y
and X
i f
and Y
manganese complex. The complex is a mononuclear manganese(III)
i
complex and shows excellent catalytic effects, contrary to [Mn
styrenes [7].
(
bpaeOH)(NCS)
the synthesis, crystal structure, and catalytic activities of [Mn(Hpmidip)
]·CH OH (1).
2 3 2
] and [Mn(bpaeO)(N ) ] [4]. In this paper, we describe
2.4. Analysis of the OeO bond cleavage products generated from the
oxidation reactions of substrates by PPAA with manganese catalyst 1
(
N
3
)
2
3
−
2
PPAA (4 × 10
catalyst (2.8 × 10
mmol) was added to a mixture of manganese
2. Experimental section
−3
−1
mmol), substrate (0–1.6 × 10
(1/1), 1.0 mL). The mixture was shaken for 5 min
at ambient temperature. Each reaction was analyzed by GC/mass with
0 μL aliquots taken periodically from the reaction solution. Product
mmol), and sol-
2 2
vent (MeCN/CH Cl
All chemicals used in the synthesis were of reagent grade and used
without further purification. N-(2-Pyridylmethyl)iminodiisopropanol
pmidip) was prepared according to the literature procedure [2a].
1
(H
2
yields and conversions were quantified, compared to dodecane as an
internal standard. All reactions were performed three times, and the
average of conversions and yields are represented. Product yields and
conversions were based on substrate or PPAA.
Olefins, epoxides, 2-cyclohexen-1-ol, 2-cyclohexen-1-one, benzalde-
hyde, acetonitrile, dichloromethane, dodecane and m-CPBA (65%) were
purchased from Aldrich Chemical Co. and were used without additional
purification. Peroxyphenylacetic acid (PPAA) was synthesized ac-
cording to the literature method [6]. Solvents used in inert-atmosphere
reactions were dried and degassed using standard procedures. UV/Vis
absorption spectra were recorded with a SCINCO S-2100 spectro-
photometer and a Perkin Elmer model Lambda 2S UV/Vis spectrometer.
Infrared spectra were recorded with a Thermo Fisher Scientific IR200
2.5. Competitive epoxidations of cis-2-octene and trans-2-octene by m-
CPBA with manganese catalyst 1
m-CPBA (4 × 10−2 mmol) was added to a mixture of trans-2-octene
(
0.01–0.08 mmol), cis-2-octene (0.01–0.08 mmol), and manganese cat-
−1
spectrophotometer ( ± 1 cm ) using KBr disk. Elemental analyses
were carried out using a Fisons/Carlo Erba EA1108 instrument in air.
Flash column chromatography was performed with 230–400 mesh si-
−3
alyst (2.8 × 10 mmol). The mixture was shaken for 5 min at ambient
temperature. Each reaction was analyzed by GC/mass with 10 μL ali-
quots taken periodically from the reaction solution. Product yields and
conversions were quantified, compared to dodecane as an internal
standard. All reactions were performed three times, and the average of
conversions and yields are represented. Product yields and conversions
were based on substrate or m-CPBA.
1
lica gel using wet-packing method. H NMR spectra were recorded on a
1
13
Varian AS400 (399.937 MHz for H and 100.573 MHz for C spectro-
meter) and chemical shifts were recorded in ppm. Analysis for epox-
idation products was performed by using YL6500 gas chromatograph
(
Hewlett-Packard, HP-FFAP or DB-5).
2.6. X-ray crystallographic data collection and refinement
3 2 3
2.1. Synthesis of [Mn(Hpmidip)(N ) ]·CH OH (1)
Single crystal of 1 was coated with paratone-N oil and the diffrac-
tion data measured at 100(2)
K with synchrotron radiation
To
a
methanol solution (4 mL) of Mn(NO
3
)
2
·4H
2
O
(50 mg,
2
pmidip
(
λ = 0.63000 Å) on an ADSC Quantum-210 detector at 2D SMC with a
0
(
.2 mmol) was added dropwise a methanol solution (4 mL) of H
silicon (1 1 1) double crystal monochromator (DCM) at the Pohang
Accelerator Laboratory, Korea. The ADSC Q210 ADX program [8] was
used for data collection (detector distance is 63 mm, omega scan;
Δω = 1°, exposure time is 1 sec per frame) and HKL3000sm (Ver. 703r)
45 mg, 0.2 mmol) and sodium azide (26 mg, 0.4 mmol). The color of
the mixture solution became dark brown. The solution was stirred for
0 min at room temperature. Dark brown crystals of 1 were obtained by
diffusion of diethyl ether into the dark brown solution for 3 days and
were washed with diethyl ether and dried in air. Yield: 53 mg (66%).
FT-IR (KBr, cm ): 3415, 3133(s, br), 3030, 2947, 2855, 2070, 2042,
618. Anal Calcd for C12 19MnN : C, 39.78; H, 5.29; N, 30.93;
Found: C, 40.17; H, 5.65; N, 30.98.
2
[
9] was used for cell refinement, reduction and absorption correction.
−
1
The crystal structure of 1 was solved by direct methods [10], and re-
fined by full-matrix least-squares refinement using the SHELXL-2014
computer program [11]. The positions of all non-hydrogen atoms were
refined with anisotropic displacement factors. All hydrogen atoms were
placed using a riding model, and their positions were constrained re-
lative to their parent atoms using the appropriate HFIX command in
SHELXL-2014, except C8 (C8A and C8B). That is, C8 in 1 has large
thermal disorder and thus is treated using PART command without
fixing hydrogen atoms. The crystallographic data and the result of re-
finements are summarized in Table 1.
1
H
8 2
O
2
.2. Olefin epoxidations by m-CPBA with manganese catalyst 1
−
1
m-CPBA (1 × 10
mmol) was added to a mixture of manganese
−
3
−2
catalyst (2.8 × 10 mmol), substrate (3.5 × 10 mmol), and solvent
MeCN/CH Cl (1/1), 1.0 mL). The mixture was shaken for 5 min at
ambient temperature. Each reaction was analyzed by GC/mass with
0 μL aliquots taken periodically from the reaction solution. Product
(
2
2
1
3. Results and discussion
yields and conversions were quantified, compared to dodecane as an
internal standard. All reactions were carried out three times, and the
average of conversions and yields are represented. Product yields and
conversions were based on substrate.
3.1. Synthesis and characterization
The
reaction
of
one
equiv
of
N-(2-pyridylmethyl)
2