U.S. patent application number 09/888589 was filed with the patent office on 2003-01-16 for novel synthesis of phthalocyanines by microwave irradiation.
Invention is credited to Chen, Jun-Rong, Hu, Andrew Teh, Hwu, Herng-Dar, Lee, Chung-Chun, Lee, Ming-Chia, Liu, Lung-Chang, Tseng, Tsai-Wie.
Application Number | 20030010621 09/888589 |
Document ID | / |
Family ID | 25393482 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030010621 |
Kind Code |
A1 |
Hu, Andrew Teh ; et
al. |
January 16, 2003 |
NOVEL SYNTHESIS OF PHTHALOCYANINES BY MICROWAVE IRRADIATION
Abstract
This invention provides a novel process for preparing soluble
phthalocyanines by microwave irradiation in the absence of any
organic solvent. Three different starting materials, i.e.
t-butylphthalic anhydride, t-butyl phthalonitrile and metal-free
H.sub.2Pc (tetra-t-butylphthalocyanine) have been adopted ,
respectively. The starting material with proper metal compound,
such as chloride or acetate were irradiated in a commercial
microwave oven for a period of 1 to 30 minutes at a power of
200.about.900 W. This process is noted to reduce drastically
reaction time of MPc formation from 8.about.24 hours to 10.about.30
minutes due to its unique heating by microwave irradiation.
Sandwiched type MPc.sub.2(such as Lu Pc.sub.2) can be produced only
through metal replacement from metal-free phthalocyanine by
microwave irradiation.
Inventors: |
Hu, Andrew Teh; (Hsin Chu
City, TW) ; Tseng, Tsai-Wie; (Tao Yuan Hsein, TW)
; Hwu, Herng-Dar; (Taoyuan Hsien, TW) ; Liu,
Lung-Chang; (Hsin Chu City, TW) ; Lee,
Chung-Chun; (Hsin-Chu, TW) ; Lee, Ming-Chia;
(Hsin-Chu, TW) ; Chen, Jun-Rong; (Hsin-Chu City,
TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
25393482 |
Appl. No.: |
09/888589 |
Filed: |
June 26, 2001 |
Current U.S.
Class: |
204/157.72 |
Current CPC
Class: |
C09B 47/062 20130101;
C09B 47/067 20130101; C09B 47/085 20130101 |
Class at
Publication: |
204/157.72 |
International
Class: |
C07B 031/00 |
Claims
We claim:
1. A novel synthesis of phthalocyanines by microwave irradiation in
the absence of any organic solvent comprises a process as follows:
(1) choosing starting material according to what kind of metal Pc
or metal-free Pc of central material to be synthesized; (2)
preparing accordant metal chloride or acetate in according with
said metal Pc to be synthesized; (3) grinding said starting
material and said metal chloride or acetate throughly and blending
homogeneously into mixed powder; (4) to place said mixed powder
into a microwave oven; (5) turning on the microwave oven at an
adequate power to a predetermined period of time for completion of
reaction; and (6) taking the product it is necessary to clean or
extract.
2. A process as in claim 1 in which step (1) includes using
t-butyl-phthalic anhydride, t-butyl-phthalonitrile, and metal-free
tetra-t-butyl-phthalocyanine (H.sub.2Pc) as starting material.
3. A process as in claim 1 wherein said central material of said
metal Pc is one of the group as Co, Ni, Cu, Mg, Al, Pd, Sn, Tb, Lu,
Dy, Ce, La, Zn.
4. A process as in claim 1 wherein said central material of said
metal-free Pc is H atom.
5. A process as in claim 1 in which step (5) adequate power between
200 and 900 W.
6. A process as in claim 1 in which step (5) reaction took 1
between 1 and 30 minutes.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel process for
preparing soluble phthalocyanines by microwave irradiating starting
materials in the absence of any organic solvent.
[0003] 2. Description of the Related Prior Art
[0004] Phthalocyanines exhibit extremely good stability and
photoelectric properties due to its unique chemical structure, and
hence have been used widely. They are currently the largest
consumed dyes and/or pigments in the world, and have a role in
application for the high technology industry.
[0005] Phthlocyanines can be made into a film that in turn can be
fabricated into to an element by means of a variety of methods.
Among those methods, the spin-coating has the lowest
cost.sup.(1-2). Films made from phthalocyanines have been applied
over various fields such as photo-recording materials.sup.(3-4),
gas sensors.sup.(5), electrochromic elements.sup.(6), non-linear
optics (NLO).sup.(7) and photocells.sup.(8).
[0006] The structural formula of phthalocyanines is given in FIG.
1, wherein R represents alkyl, t-butyl , or alkoxy group like
pentoxy , Mt represents central material of metal , like Co, Ni,
Cu, Mg, Al, Pd, Sn, Tb, Ce, La, Zn, Lu or metal-free like H
atom.
[0007] Microwave had been developed from the radar during the
Second World War. At that time, microwave emitted from the radar
was found to be able to dry big ceramic objects. The application of
microwave for the household electric commodities had been, however,
since 1970. Nevertheless, in recent years, many studies have been
devoted for exploring the feasibility of the application of
microwave on the chemical reaction.
[0008] Microwave is an energy in a form of electromagnetic wave. It
is a non-ionization radiation that can induce the migration of
electron and the rotation of dipole moment, and hence cause the
motion of a molecule. Microwave heating is different from
conventional heating method mostly in its mode of energy delivery.
Traditional heating method delivers heat energy by conducting
through a container containing the solution, and homogeneously
distributes the heat to the solution and hence raises temperature
thereof. On the contrary, microwave heating delivers heat by
radiation, and therefore, can heat reactants directly and
accordingly, promote its efficiency.
[0009] Synthesis of phthalocyanine by microwave irradiation had
been proposed firstly by Ahmad Shaabani.sup.(12) in 1998 with
phthalic anhydride having no side group as the starting material.
This method had, however, a disadvantage in that the phthalocyanine
thus synthesized had a poor solubility. It is insoluble in almost
all solvent other than concentrated sulfuric acid. In 1999, Cezar
Ungurenasu.sup.(13) proposed a process for preparing phthalocyanine
by microwave irradiation with phthalonitrile or diiminoisoindoline
as the starting material. The product thus prepared had a defined
solubility, however, it was disadvantageous in that a solvent must
involve in the reaction, i.e., it was not a dry preparation, and
hence was high in its production cost. Further, it differed from
the scope claimed by the present invention.
[0010] The traditional syntheses of phthalocyanine, no matter what
starting material is used, all need a relatively long reaction time
and a considerably high energy to provide sufficient kinetic energy
to overcome the reaction kinetic barrier and hence promote the
collision probability and energy of molecules, that results in low
efficiency. Accordingly, the object of the present invention is to
provide a novel process for preparing phthalocyanine by microwave
irradiation that can eliminate the above-described disadvantage
associated with the traditional process. Consequently, it is
possible to shorten the reaction time, produce soluble
phthalocyanines that can be used to fabricate elements avoiding
expensive vacuum sputtering method by utilizing instead of the
cheap spin-coating method, and thus increase its industrial
practicability.
SUMMARY OF THE INVENTION
[0011] Accordingly, the invention provides a novel process for
preparing soluble phthalocyanines by microwave irradiation,
characterized in that it involves no solvent so as to lower
unnecessary heat consumption; increase collision frequency and
effective collision probability of reacting molecules and hence
increase the reaction yield and reaction rate; in which there are
three different kinds of starting materials, i.e. (1)
t-butyl-phthalic anhydride, (2) t-butyl-phthalonitrile, and (3)
metal-free tetra-t-butyl-phthalocyanine H.sub.2Pc have been chosen
for preparation of soluble metal containing tetra-t-butyl
phthalocyanines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] The novel process for preparing phthalocyanine according to
the invention comprises reacting starting materials with various
metal compounds in the absence of any solvent under microwave
irradiation in a microwave oven. Metal chlorides and acetates are
used as metal compounds.
[0013] The starting materials used herein can be any conventional
starting material useful for preparing phthalocyanine, for example,
phthalic anhydride, phthalonitrile and metal-free
phthalocyanine.
[0014] In the process for preparing phthalocyanine by microwave
irradiation, the starting reactants are placed in a heat-resistant
quartz vessel of 10 ml. Then, the vessel is placed on the rotation
table in the microwave oven. During the microwave irradiation,
reactant molecules will have their dipole moments rotating in
accordance with the change of the microwave field, and hence,
increase collision frequency and effective collision probability,
as described above. As the result, the reaction can be accelerated
and the reaction yield can be promoted.
[0015] Thus prepared phthalocyanine can be represented by the
formula shown in in FIG. 1.
[0016] wherein
[0017] R is an alkyl group such as t-butyl, or an alkoxy group like
pentoxy;
[0018] Mt is metal or non-metal, like Co, Ni, Cu, Mg, Al, Pd, Sn,
Tb, Lu, Dy, Ce, La, Zn or H atom.
[0019] The invention will be further illustrated in more detailed
by the following examples, but not limited by these
descriptions.
EXAMPLES
[0020] 5 examples are provided for illustrating the preferred
embodiment of the novel process according to the invention. The
invention is, however, not limited by these examples. Among these,
example 1 uses phthalic anhydride as the starting material;
examples 2 and 3 employ phthalonitrile as the starting materials,
wherein, the center in the ring of example 3 is a non-metal H atom;
example 4 and 5 use H.sub.2Pc as the starting material, wherein,
the central metal in the example 5 is a rare earth metal Lu, such
that a sandwich type of phthalocyanine has been formed which can be
identified by mass spectrometry. It should be noted Lu
diphthalocyanine can only be prepared by using H.sub.2Pc as the
starting material. All the examples are reacted in a microwave oven
at a power of 200.about.900 W for a period of 1 to 30 minutes.
Example 1
[0021] Synthesis of Cu tetra-t-butyl-phthalocyanine using
4-tert-butyl-phthalic anhydride (4 g, 19.6 mmol), copper chloride
(0.72 g, 5.45 mmol), urea (48 g, 0.8 mmol), ammonium chloride
(4.048 g, 75.7 mmol) and ammonium molybdate (0.44 g, 2.23 mmol)
were pulverized in a mortar and then, placed in a quartz vessel of
50 ml , and irradiated in a microwave oven at 440 W for 15 minutes.
Thereafter, the reaction product was rinsed with an amount of
demonized water, filtered under suction and the solid was dried
under vacuum at 120.degree. C.
[0022] To the dried product, 500 ml of 2% HCl was added and the
resulting mixture was heated to boil for several minutes. After
filtering and drying, it was added into a 500 ml of 1% aqueous NaOH
solution, boiled for several minutes and then filtered and dried.
The acid/base washing was repeated several times. The oven-dried
crude product was dissolved in dichloromethane, and filtered with
suction. The filtrate was concentrated under reduced pressure and
dried in vacuum to yield a bluish solid. The solid was
recrystallized from ethanol and dichloromethane (5:1) to obtain Cu
phthalocyanine with a yield of 47%.
[0023] IR (KBr); 2962, 2896, 2855, 1616, 1528, 1484, 1365, 1338,
1256, 1195, 1145, 1082, 1056, 923, 828, 745, 688, 553
cm.sup.-1.
[0024] MS: m/z 800(M.sup.+).
[0025] UV-Vis(n-hexane).quadrature..sub.max: 670 nm.
Example 2
Synthesis of Mg tetra-t-butyl-phthalocyanine Using
4-tert-butyl-phthalonit- rile
[0026] 4-tert-butyl-phthalonitrile (0.5 g, 2.72 mmol) and magnesium
chloride (0.0645 g, 1.36 mmol) were ground homogeneously and the
resulting mixture was then placed in a quartz vessel. After
addition of 5 ml 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), the
quartz vessel was irradiated in a microwave oven at 440 W for 10
minutes. A mixture of toluene and water (1:2 v/v) was added to
precipitate the product. After filtering and drying, the product
was Soxhlet extracted with methanol. 0.4380 g of Mg phthalocyanine
was obtained. The yield was 85%.
[0027] IR(KBr); 2954, 1640, 1481, 1441, 1361, 1320, 1253, 1196,
1145, 1081, 1042, 916, 826, 751, 688, 538 cm.sup.-.
[0028] MS: m/z 761(M.sup.+).
[0029] UV-Vis(methanol).quadrature..sub.max: 674 nm.
Example 3
Synthesis of Central Metal-free tetra-t-butyl-phthalocyanine Using
4-tert-butyl-phthalonitrile
[0030] 4-tert-butyl phthalonitrile (0.5 g, 2.72 mmol) was placed in
a quartz vessel. After addition of 5 ml DBU, the quartz vessel was
irradiated in a microwave oven at 440 W for 10 minutes, and a
mixture of toluene and water (1:2 v/v) was added to precipitate the
product. After filtering and drying, the product was Soxhlet
extracted with methanol. 0.4144 g of central metal-free
phthalocyanine (H.sub.2Pc) was obtained . The yield was 83%.
[0031] IR (KBr); 2955, 1616, 1456, 1361, 1316, 1254, 1182, 1007,
869, 823, 743, 518 cm.sup.-.
[0032] MS: m/z 740(M.sup.+).
[0033] UV-Vis(TUF).quadrature..sub.max: 696 nm.
Example 4
Synthesis of Zn-tetra-t-butyl-phthalocyanine through Metal
Replacement
[0034] Central metal-free tetra-t-butyl-phthalocyanine (0.02 g,
0.027 mmol) and zinc chloride (7.40.times.10.sup.-3 g, 0.054 mmol)
were ground homogeneously and the resulting mixture was then placed
in a quartz vessel. The vessel was then irradiated in a microwave
oven at 440 W for 10 minutes, and a mixture of toluene and water
(1:2 v/v) was added to wash the product. After filtering and
drying, 6.30.times.10.sup.-3 g of zinc tetra-t-butylphthalocyanine
was obtained. The yield was 29%.
[0035] IR (KBr); 2953, 1611, 1485, 1441, 1389, 1328, 1277, 1253,
1215, 1186, 1146, 1084, 1043, 954, 917, 890, 823, 759, 743, 688,
667, 510 cm.sup.-1.
[0036] MS: m/z 801(M.sup.+).
[0037] UV-Vis(methanol).quadrature..sub.max : 673 nm.
Example 5
Synthesis of Lu tetra-t-butyl-diphthalocyanine through Metal
Replacement
[0038] Central metal-free tetra-t-butylphthalonitrile (0.2 g, 0.27
mmol) and lutetium acetate (0.0953 g, 0.27 mmol) were ground
homogeneously and the resulting mixture was placed in a quartz
vessel. 3 ml of DBU was added to the vessel ,and the vessel was
irradiated in a microwave oven at 440 W for 10 minutes. A mixture
of methanol and water (1:2 v/v) was added to wash the product.
After filtering and drying, 0.1581 g of Lu
tetra-t-butylphthalocyanine was obtained. The yield was 71%.
[0039] IR(KBr): 2956, 1637, 1608, 1482, 1455, 1362, 1315, 1275,
1253 ,1223, 1194, 1140, 1077, 1043, 1023, 915, 822, 749, 673, 531,
505 cm.sup.-1.
[0040] MS: m/z 1649(M.sup.+).
[0041] UV-Vis(n-hexane).quadrature..sub.max: 676 nm.
[0042] Spectra of Various Phthalocyanines
[0043] Table 1 exhibits characteristic absorption peaks in Uv/Vis
spectra of various mentioned above phthalocyanines obtained in
examples mentioned above. Owing to the unique chemical structure,
phthalocyanine exhibits specific optical characteristics. From the
UV/Vis spectra, it is clear that two main strong absorption regions
were present, namely, Q regions around 670 nm and B region around
340 nm. Both of the two regions are related to
.quadrature.-.quadrature.* transition and the resonance on their
rings.
1TABLE 1 Characteristic absorption peaks in UV/Vis spectra of
various lab- made phthalocyanines Name Q region B region Name Q
region B region Name Q region B region CoPc 664 331 ZnPc 673 337
TbPc.sub.2 684 347 NiPc 665 332 DyPc.sub.2 675 346 LuPc.sub.2 676
346 CuPc 670 334 PdPc 657 329 LaPc.sub.2 647 334 MgPc 674 348 SnPc
684 341 H.sub.2Pc 696, 659 340
[0044] Solubilities of Various Phthalocyanines
2TABLE 2 displays solubility of various lab-made phthalocyanines,
wherein: .circleincircle., soluble (>3 wt. %); .largecircle.,
slightly soluble (1 wt. % .about. 3 wt. %); .DELTA., hardly soluble
(<1 wt. %). Name toluene THF n-hexane acetone methanol H.sub.2Pc
.DELTA. .DELTA. .DELTA. .DELTA. .DELTA. ZnPc .circleincircle.
.circleincircle. .largecircle. .DELTA. .DELTA. MgPc
.circleincircle. .circleincircle. .largecircle. .largecircle.
.DELTA. CoPc .largecircle. .largecircle. .DELTA. .largecircle.
.DELTA. CuPc .largecircle. .largecircle. .DELTA. .DELTA. .DELTA.
NiPc .largecircle. .largecircle. .DELTA. .largecircle. .DELTA.
TbPc.sub.2 .largecircle. .largecircle. .DELTA. .largecircle.
.DELTA. LaPc.sub.2 .circleincircle. .circleincircle.
.circleincircle. .circleincircle. .DELTA.
[0045] The Correlation of Reaction Condition with Yield of
Phthalocyanine
[0046] Table 3 sets forth the reaction condition used in various
example and yields of phthalocyanine prepared.
3TABLE 3 The correlation of reaction condition with yield of
phthalocyanine Reaction Microwave time Yield Name Starting material
power (W) (minute) (%) CuPc t-butyl phthalic anhydride 440 10 47
MgPc t-butyl phthalonitrile 440 10 85 H.sub.2Pc t-butyl
phthalonitrile 440 10 83 ZnPc tetra-t-butylphthalocyanine 440 10 29
(H.sub.2Pc) LuPc.sub.2 tetra-t-butylphthalocyanine 440 10 71
(H.sub.2Pc)
[0047] Advantages of the Invention
[0048] The invention provides several advantages as follows:
[0049] 1. Due to the unique property of heating associated with
microwave irradiation itself instead of heating in condition and
convection fashion involved in conventional synthesis, undue heat
energy consumption can be lowered;
[0050] 2. Since the operation of microwave field may cause dipolar
rotation of reacting molecules and hence increase the collision
frequency and the effective collision probability, the reaction
time can be reduced drastically from 8.about.24 hours to
10.about.30 minutes and the yield can be raised;
[0051] 3. It can produce phthalocyanine that is soluble in organic
solvent and can be used to fabricate elements by utilizing the
convenient spin-coating method instead of expensive vacuum
sputtering method, and thus increase its industrial practicability;
and
[0052] 4. Since none of any organic solvent is involved in the
reaction according to the invention, the disposal of the organic
waste can be greatly reduced and the impact onto environment can be
largely avoided.
[0053] Many changes and modifications in the above-described
embodiment of the invention can, of course, be carried out without
departing from the scope thereof. Accordingly, to promote the
progress in science and the useful arts, the invention is disclosed
and is intended to be limited only by the scope of the appended
claims.
[0054] References:
[0055] 1. P. N. Moskalev et al. 1979, Russian Journal of Inorganic
Chemistry, 24, 2, 188.
[0056] 2. K. Takeshita et al. 1991. Bull. Chem. Soc. Jpn., 64,
1167.
[0057] 3. P. Kivits et al. 1981. Applied Physics, A26, 101.
[0058] 4. M. F. Dautartas et al. 1985. Applied Physics, A36,
71.
[0059] 5. Y. Q. Liu et al. 1998. Supramolecular Science, 5,
507.
[0060] 6. J. Silver et al. 1997. IEE Proc. Circuits Devices Syst.,
144, 2, 123.
[0061] 7. Hari Singh Nalwa et al. 1995. Thin Solid Films, 254,
218.
[0062] 8. K. Petritsch et al. 1999. Synthetic Metals, 102,
1776.
[0063] 9. S. Caddick. 1995. Tetrahedron, 51, 10403.
[0064] 10. Andre Loupy et al. 1998. Synthesis, 1213.
[0065] 11. M. H. Young, et al. 1998. Chemistry, 56, 4, 269.
[0066] 12. Ahmad Shaabani. 1998. J. Chem. Research, 672.
[0067] 13. Cezar Ungurenasu. 1999. Synthesis, 10, 1729.
* * * * *