EFFECTS OF PORPHYRIN DEFORMATION ON THE 13C AND 1H NMR CHEMICAL SHIFTS
11
(ortho-CH3), 14.8 (ortho-CH3), 28.1 (para-CH2), 14.8
(para-CH3).
were solved by the direct method and refined in the
SHELXTL program [40]. The all non-atoms were
refined as anisotropy and all hydrogen positions were
calculated. The crystal data and structure refinement for
[Mn(OMTPP)Cl] and [Mn(TiPrP)Cl] are listed in Tables
S1 and S2, respectively.
[Mn(TEtP)Cl]. Free base porphyrin, (TEtP)H2
(200 mg, 0.473 mmol), was added to a 500 mL three-
necked flask equipped with a pressure equalizing
dropping funnel, reflux condenser, and a magnetic
stirrer, and was dissolved in 240 mL CHCl3 and
60 mL CH3OH. The solution was stirred vigorously
under argon atmosphere, to which the methanol solution
(20 mL) of solid MnCl2 (110 mg, 0.874 mmol) was
added through the dropping funnel in 20 min. The
reaction was monitored by UV-vis spectroscopy. The
CH3OH solution of MnCl2 was repeatedly added. When
799 mg (6.35 mmol) of MnCl2 was added in total for
4 h, the free base porphyrin was almost disappeared in
the UV-vis spectrum. The solvents were evaporated and
the remaining solid was dissolved into 200 mL CH2Cl2.
The solution was washed with 1 M aq. HCl repeatedly
until the aqueous layer was colorless. The organic
layer was collected and rotary evaporated to dryness.
The crude [Mn(TEtP)Cl] thus obtained was purified
by column chromatography on alumina. Elution with
CH2Cl2 and then with CH3OH/CH2Cl2 1:9 eluent
yielded green fractions, which were washed twice with
1 M HCl aqueous solution and then washed with water.
The solution was dried over anhydrous Na2SO4 and
was then rotary evaporated to dryness. The green solid,
[Mn(TEtP)Cl] was vacuum-dried at 60°C.Yield 68.1 mg
(28%). UV-vis (CH2Cl2): lmax, nm 376, 401, 480, 538,
Synthesis
Free base porphyrins (Por)H2. Tetraarylporphyrins
(4-X-TPP)H2 where X is OMe, Me, H, F, Cl, Br, CF3,
and CN were prepared by the condensation reactions
between substituted benzaldehyde and pyrrole according
to the Alder’s methods [41]. Free base porphyrins such as
(2,4,6-Me3-TPP)H2 [42], (2,4,6-Et3-TPP)H2 [43], (2,6-Cl2-
TPP)H2 [42], (TiPrP)H2 [24], (TEtP)H2 [44], (OETPP)H2
[16], and (OMTPP)H2 [16] were similarly prepared by the
Lindsey’s method in CHCl3 solution using BF3-etherate.
[Mn(Por)Cl]. Insertion of manganese ion to free
base porphyrins was performed by the slightly modified
methods reported previously [32, 45]. Typical procedures
are described below.
[Mn(2,4,6-Et3-TPP)Cl]. Free base porphyrin,
(2,4,6-Et3-TPP)H2 (205 mg, 0.215 mmol), was added to
a 500 mL three-necked flask equipped with a pressure
equalizing dropping funnel, reflux condenser, and a
magnetic stirrer, and was dissolved in 100 mL DMF.
Argon was bubbled into the DMF solution while
it was vigorously stirred for 10 min. Solid MnCl2
(110 mg, 0.874 mmol) dissolved into 20 mL DMF
was added to the refluxed DMF solution in 20 min
through the dropping funnel under argon atmosphere.
The reaction was monitored by UV-vis spectroscopy.
The DMF solution of MnCl2 was repeatedly added into
the reaction mixture until no appreciable free base was
detected by UV-vis. Total amount of MnCl2 added was
610 mg (4.85 mmol). After the solution was refluxed
for 5 h, DMF was removed under reduced pressure.
The remaining solid was dissolved into 100 mL
CH2Cl2, and the solution was washed with 1 M HCl
aqueous solution repeatedly until the aqueous layer was
colorless. The organic layer was collected and rotary
evaporated to dryness. Crude [Mn(2,4,6-Et3-TPP)Cl]
thus obtained was purified by column chromatography
on alumina. Elution with CH2Cl2 and then with CH3OH/
CH2Cl2 1:9 gave green fractions, which were collected,
washed twice with 1 M aq. HCl and then with water.
The solution was dried over anhydrous Na2SO4 and
was then rotary evaporated to dryness. The green solid,
[Mn(2,4,6-Et3-TPP)Cl], was vacuum-dried at 100°C.
Yield 92 mg (41%). UV-vis (CH2Cl2): lmax, nm 375,
1
597, 633. H NMR (300 MHz, CD2Cl2, 25°C): dH,
ppm -20.6 (8H, Py-H), 9.7 (8H, meso-CH2), 2.3 (12H,
meso-CH3), 1.5 (ortho-CH3), 2.9 (para-CH3). 13C NMR
(75.5 MHz, CD2Cl2, 25°C): dC, ppm 136 (meso), 385
(a-Py), -181 (b-Py), 136 (meso-CH2), 104 (meso-CH3).
[Mn(OMTPP)Cl]. [Mn(OMTPP)Cl] was similarly
prepared from free base (OMTPP)H2 (83.5 mg, 0.115
mmol) and MnCl2 (32.5 mg, 0.258 mmol) in refluxed
DMF. The crude [Mn(OMTPP)Cl] was purified by
chromatography on alumina. Yield 20.3 mg (22%).
UV-vis (CH2Cl2): lmax, nm 377, 405, 496, 595, 635.
1H NMR (300 MHz, CD2Cl2, 25°C): dH, ppm 37 (24H,
Py-CH3), 11.4 (8H, ortho-H), 5.3 (8H, meta-H), 9.8 (4H,
para-H). 13C NMR (75.5 MHz, CD2Cl2, 25°C): dC, ppm
-302 (meso), 314 (a-Py), -27 (b-Py), -29 (b-Py-CH3),
398 (ipso), 84 (ortho), 120 (meta), 117 (meta), 124
(para).
Spectral measurement
1H and 13C NMR spectra were measured on a JEOL
1
LA300 spectrometer operating at 300.4 MHz for H.
1
401, 481, 536, 588, 624. H NMR (300 MHz; CD2Cl2,
Chemical shifts were referenced to the residual peaks of
deuterated solvents; dichloromethane (d = 5.32 ppm for
1H and 53.8 ppm for 13C) and methanol (d = 3.30 ppm for
1H and 49.0 ppm for 13C). UV-vis spectra were measured
on a Shimadzu MultiSpec-1500 spectrophotometer in
CH2Cl2 or CH3OH at ambient temperature.
25°C): dH, ppm -19.4 (8H, Py-H), 8.2 (4H, meta-H), 8.0
(4H, meta-H). 13C NMR (75.5 MHz, CD2Cl2, 25°C): dC,
ppm 122 (meso), 392 (a-Py), -156 (b-Py), 187 (ipso),
184 (ortho), 172 (ortho), 131 (meta), 128 (meta),
144 (para), 33.3 (ortho-CH2), 28.1 (ortho-CH2), 15.1
Copyright © 2016 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2016; 20: 11–13