JPH0653744B2 - Alkyl cyanophthalocyanine compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to a phthalocyanine compound containing both an alkyl group and a cyano group.

[Conventional technology]

It is known that the alkyl-substituted phthalocyanine compound has higher solubility than ordinary unsubstituted phthalocyanine, and is expected to have functions such as conductivity, photoconductivity, and gas sensor. Regarding the alkyl-substituted phthalocyanines reported so far, it has been shown that a t-butyl-substituted phthalocyanine can be formed into a thin film by using the Langmuir project (hereinafter abbreviated as LB) method [Kovacs GJ (Kovac
s GJ), Cana Deyan Journal of Physics (Can.J.Phys.), Volume 63, 346-349 (1985), fryer JR, etc.
Nature, Volume 313, Volumes 382-384
P. (1985), Baker S., Thin Solid Film, 99th.
Vol. 53-59 (1983)]. According to these reports, the measured value and the calculated value do not always match with respect to the molecular limit cross-sectional area, and the measured value varies depending on the reporter. The reason for this is that the present inventors have found that when the phthalocyanine solution is developed on the water surface, a somewhat higher-order aggregate is formed because the phthalocyanine ring is substituted with a weakly polar t-butyl group. I'm estimating. The conductivity of these t-butyl-substituted phthalocyanine thin films has not been reported, but JP-A-58-141246 discloses that the central metal is Cu and the conductivity is 20 times higher by exposing it to ammonia gas. It has been shown to rise. Although not t-butyl substituted, tri (iso-
It has been reported that the conductivity of propylaminomethylene) copper phthalocyanine LB film was increased by 6 times by exposing it to NO ₂ gas [Roberts GG]
In addition, IEEE-Proceeding I, Vol. 130, pp. 260-263 (1983)].

[Problems to be solved by the invention]

These phthalocyanine thin films are composed of acceptor gas,
The change in conductivity with respect to the donor gas is extremely small, and therefore the sensitivity is extremely low. Further, from the viewpoint of a gas sensor, the recovery responsiveness to a decrease in gas concentration is an important issue in practical use. As a result of investigating the responsiveness of t-butyl-substituted nickel phthalocyanine to the LB film to I ₂ and triethylamine gas, the result shows a rapid rise upon introduction of I ₂ gas and a good response, but to gas discharge. However, there is a fatal defect that it takes nearly 60 minutes to restore the initial low conductive state (see Comparative Example described later). Further, it is possible to obtain the result that the response is slow to a gas such as ammoniacal triethylamine, and the change in conductivity is about twice as high.

An object of the present invention is to provide a phthalocyanine compound capable of forming a uniform monomolecular film or a cumulative film thereof, which can dramatically improve the sensitivity (dynamic range) to a donor gas and an acceptor gas.

[Means for solving problems]

Briefly describing the present invention, the present invention relates to an alkylcyanophthalocyanine compound, which is represented by the following general formula I: (In the formula, R ₁ represents an i-propyl group or a t-butyl group, and R ₁
Is an i-propyl group, R ₂ is a cyano group and R ₃ is hydrogen, and when R ₁ is a t-butyl group, R ₂ is hydrogen and R ₃ is a cyano group). It is characterized by being done.

The present invention slightly increases the electron affinity and ionization potential by introducing a cyano group into the alkyl phthalocyanine ring structure, and therefore the conductivity increase with respect to ammonia gas is increased by 4 × 10 ² times, and the conductivity increase with respect to iodine gas is increased. Has a high conductivity change of 5 × 10 ³ times, the degree of change in conductivity is large for both donor-type and acceptor-type gases, and the response speed to gas introduction and discharge is extremely fast. It has the most main feature. When this is compared with the conventional compounds, 20 times the conductivity increases with respect to ammonia gas, has high sensitivity characteristics different of 10 ³ times the acceptor gas such as I ₂ gas, more in particular I ₂ The difference is that the gas discharge response speed is 200 to 500 times better.

〔Example〕

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

Example 1 Synthesis of tetra-t-butyltetracyanophthalocyanine compound The reaction scheme is shown below. (Bu: Butyl) (a) Synthesis of compounds (2) and (3): Starting material (1) 274 g, iron powder and iodine 1 g each in 500 m of carbon disulfide,
At 5 ° C., 115 m of bromine was gradually added dropwise. After completion of HBr gas generation, washing and neutralization treatment was carried out according to a conventional method, and vacuum distillation was performed. Boiling point 71-72 ° C / 3 mmHg. Yield 366g (86
%). ^{From the 1} H- and ¹³ C-NMR spectra, (2) / (3) =
It was confirmed to be a mixture of 88/12.

(b) Synthesis of compound (4): 66 g of the mixture of (2) / (3), 250 m of carbon disulfide, 1 g of iron powder and 1 g of iodine were added, respectively.
Bromine 60 m was gradually added dropwise at -5 ° C. After completion of HBr gas generation, washing and neutralization were carried out according to a conventional method, and vacuum distillation was performed.
Boiling point 93-94.5 ℃ / 1mmHg. Yield 86 g (60%). ¹ H-
And ₁₃ C-NMR spectrum confirmed that the product was pure.

(c) Synthesis of compound (5): (4) 59 g, carbon disulfide 100 m
Add 0.5 g of iron and 0.5 g of iodine to room temperature, and bromide 26 m
Was gradually added. After completion of the reaction, the mixture was washed, neutralized, and distilled under reduced pressure. Boiling point 127-128 ° C / 3 mmHg. Crude yield 61g
(82%). ^{From the 1} H- and _-13 C-NMR spectra, it was revealed to be a mixture of tribromo compounds shown below. Compound
(5) is White crystals were obtained from the crude product of the tribromo compound by an ethanol recrystallization method, and it was confirmed from ¹ H- and ¹³ C-NMR spectra that the product was a pure product of (5). Analytical value (%): measured value C32.49,
H3.12, calculated value (C ₁₀ H ₁₁ Br ₃ ) C32.38, H2.99 Tribromo t-butylbenzene other than the compound (5) is (5)
Although it could be recovered from the liquid of 1., it was a liquid. This liquid tribromot-butylbenzene mixture could similarly be cyanated, as shown in Example 2 below, to yield the corresponding tricyano t-butylbenzene. By reacting this with a suitable metal chloride in 1-chloronaphthalene,
An alkyl cyanophthalocyanine corresponding to structure (18) was obtained. When the central metal was Cu (II), cuprous chloride was used to obtain a tetra-t-butyltetracyanophthalocyanine copper (II) complex (Structure 18).

Analytical value (%): Actual value C68.77, H5.35, N18.75, calculated value
(C ₅₂ H ₄₄ N ₁₂ Cu) C 69.36, H4.92, N 18.66 λmax (CHC ₃ ) 684 nm (ε = 1.9 × 10
⁵ M ⁻¹ cm ⁻¹ ) or more, it can be confirmed as the target product from the analysis value, the visible spectrum is different from phthalocyanine synthesized using (5) as a starting material, the wavelength shifts to a long wavelength, and the molecular absorption coefficient ε is , Tetra (i-propyl) tetracyanophthalocyanine copper (II) complex is almost the same,
It could be identified as a tetra (t-butyl) tetracyanophthalocyanine copper (II) complex having (18).

(d) Synthesis of compound (6): 3.6 g of (5), 5.49 g of cuprous cyanide
DMF 40 m was refluxed for 18 hours and worked up in the usual way. Purification by vacuum sublimation (100 ° C) gave a white powder. ¹ H,
It was confirmed to be the desired product by ¹³ C-NMR spectrum and IR spectrum.

Analysis value (%): Measured value C74.28, H5.25, N19.75, calculated value
(C ₁₃ H ₁₁ N ₃ ) C74.62, H5.30, N20.08 (e) Synthesis of tetra-t-butyltetracyanophthalocyanine copper complex (7): (Method 1) Compound (6) 8.2 g primary chloride Copper 0.9
9 g was heated in 1-chloronaphthalene for 6 hours, poured into methanol and reprecipitated. The precipitated solid was dissolved in chloroform and column purified. (Silica gel column, chloroform / methanol = 100/2) Yield 3.2 g (35%) λmax (CHC ₃ ) 676 nm (ε1.2 × 10 ⁵
M ^-1 cm ^-1 ) Analytical value (%): measured value C68.86, H5.21, N18.65, calculated value (C ₅₂ H ₄₄ N ₁₂ Cu) C69.36, H4.92, N18.66 visible It was confirmed to be the desired product from the spectrum and elemental analysis values.

(Method 2) Compound (5) was prepared by using (1) as a starting material in the same manner as in (a) to (c) by using bromine in an amount 3 times that of (1). Could be synthesized with. Compound
By reacting (5) with a large excess of cuprous cyanide, (7) could be directly synthesized in one pot. (5) 3.6 g, cuprous cyanide 5.4 g, and DMF 40 m were refluxed for 18 hours.
Dilute aqueous ammonia was added, the generated precipitate was separated, redissolved in chloroform, and then washed with diluted aqueous ammonia. After the solvent was distilled off under reduced pressure, the residue was separated and purified by a chromatography method (silica gel, chloroform / ethanol = 98/2). The yield of 0.43 g (19%) λmax and the elemental analysis values were the same as in the method (1).

Example 2 Synthesis of tetra-i-propyltetracyanophthalocyanine compound The reaction scheme is shown below. (Pr: propyl) The compound (13) could be obtained by the same method as shown in (a) to (c) of Example 1. In addition, the compound (15) is obtained in Example 1 (e)
It was possible to synthesize by the same method as Method 1 and Method 2.

Elemental analysis (%): Found C67.48, H4.86, N19.45, calcd _{(C 48 H 36 N 12 Cu} ) C68.27, H4.30, N19.90λmax
(CHC ₃ ) 684 nm (ε 1.8 × 10 ⁵ M ⁻¹ c
m ⁻¹ ) Here, tribromo-substituted alkylbenzene, which is a raw material for alkylcyano-substituted phthalocyanine, is used in the Friedel-Crafts reaction of bromine when tertiary carbon such as t-butyl group is substituted on the benzene ring. Due to the steric hindrance of t-butyl, it is preferentially substituted in the 3,4,5 position.
On the other hand, when a secondary or primary carbon is substituted on the benzene ring, 2,4,5-
The fact that the position is preferentially replaced was obtained as the findings of the present inventors. Particularly in the case of t-butyl group, t-
A highly symmetrical phthalocyanine in which butyl is substituted in one direction is obtained. This is because the steric effect of the Br (CN) group at the 3 (or 5) position affects the phthalocyanine cyclization.

This structure is shown in (17).

On the other hand, alkyl groups with small steric hindrance other than t-butyl (i-propyl, n-octyl, cyclohexyl, n-
Octadecyl) had no stereospecificity during cyclization, and phthalocyanine was a mixture of various isomers. These were confirmed by liquid chromatography. The structure is shown in (18).

The central metal is not limited to the Cu (II) ion shown in Examples 1 and 2, but may be, for example, K. Venkataramaman, issued 1971, Academic Press, New York City.
n), "The Chemistry of Synthetic Dyes," Volume V,
Various metals as described on pages 250-253 can be incorporated into the phthalocyanine ring.

These synthesized alkylcyano-substituted phthalocyanines are used as L
Thin film is formed by method B (horizontal deposition method), acceptor gas (iodine), donor gas (triethylamine)
The change in conductivity and the response characteristics were investigated. here,
In order to investigate the characteristics of the LB method, 5 ° C, pH7 was used in accordance with the usual method.
The π-A curve was measured at. Each result is shown as a graph in FIGS. 1 and 2.

That is, FIG. 1 is an alkylcyanophthalocyanine compound of the present invention, and FIG. 2 is a conventional alkylphthalocyanine compound having A (Å ² / molecule, horizontal axis) and π (dyne / c).
3 is a graph showing a relationship with (m, vertical axis). The abbreviations are summarized in Table 1 below.

Regarding the limit cross-sectional value of the TBP compound having only an alkyl group,
While the measured and calculated values are significantly different, the measured and calculated values for TBCP and IPCP compounds containing an alkyl group and a cyano group are almost the same, and a monomolecular film is formed on the air-water interface. You can see that The TBP and TBCP compounds had a surface pressure of 18 to 20 dynes / cm, and the IPCP compound had a surface pressure of 11 dynes / cm, and accumulated on the glass substrate. Table 2 shows the change in conductivity.

As is apparent from Table 2, the conductivity of TBPs is 0.5 to 2 × 10 ⁴ times higher than that of iodine gas, whereas the conductivity of TBPs is only 2 to 100 times higher than that of triethylamine gas. . On the other hand, TBCP and IPCP, which have increased electron affinity by introducing a cyano group, are
Similar to Ps, the conductivity was increased by 0.1 to 5 × 10 ⁴ times, and the conductivity was also increased by 0.2 to 1 × 10 ³ times with respect to triethylamine gas. On the other hand, the corresponding characteristic to iodine gas is shown in FIG. That is, FIG. 3 shows time (seconds,
6 is a graph showing the relationship between the electric conductivity σ (Scm ⁻¹ , vertical axis) and the minute (horizontal axis). TBPNi is 10 ^-4 S against iodine within 1 second
It rises to cm ^-1 while TBCPCu takes 10 ^-4 Scm in 2-3 seconds.
^{Reaches -1} . With respect to the emission of iodine gas, TBPs have a small ionization potential of 4.8 eV (determined from UPS), so it is difficult for the iodine adsorbed by phthalocyanine to escape, and it takes about 1 hour to recover the original value. In contrast, TBCP
Since Cu has a large ionization potential of 5.3 eV, iodine can be easily attached and detached, and therefore the time to recover the original value is about 15 seconds, which is extremely short. The same can be said for other alkyl phthalocyanines and alkyl cyano phthalocyanines. That is, the responsiveness to iodine is almost the same, but the recovery times are different by 200 to 500 times.

The response characteristics to triethylamine gas are shown in FIG. That is, Fig. 4 shows time (second, horizontal axis) and conductivity σ (Sc
3 is a graph showing a relationship with m ¹ , vertical axis). As is clear from this graph, both TBPNi and TBCPCu reached the saturation value in 2 seconds with respect to triethylamine, and the recovery time was extremely fast as 10 seconds. This trend was the same fast response-recovery time with other alkyl phthalocyanines and alkyl cyano phthalocyanines.

〔The invention's effect〕

As described above, the cyano group-introduced alkyl phthalocyanine compound of the present invention forms a good monomolecular film in the LB method, and the thin film has extremely high sensitivity and high speed for both acceptor gas and donor gas. It was found to have response-recovery properties. This indicates that the alkyl cyanophthalocyanine is a material that is far superior in gas detection ability to the alkyl phthalocyanines reported so far. Phthalocyanine compounds with high solubility are used for organic photoconductors, organic conductors, electrophotographic photoconductors,
Although it is a material that is of extremely high interest in relation to solar cells, it has been controlled by changing the central metal as a method of controlling electron affinity and ionization potential. The present invention has an extremely advantageous effect in that the energy level can be controlled by introducing a cyano group while maintaining high solubility.

[Brief description of drawings]

FIG. 1 shows π- of the alkylcyanophthalocyanine of the present invention.
Fig. 2 is a graph showing a curve A, Fig. 2 is a graph showing a π-A curve of a conventional alkylphthalocyanine, Fig. 3 is a graph showing a response-recovery curve of the compounds of Examples and Comparative Examples of the present invention to iodine gas, FIG. 4 is a graph showing a response-recovery curve for an example and a comparative example of the present invention with respect to triethylamine gas.

Continuation of the front page (72) Inventor Hisao Tabei, Tokai-mura, Naka-gun, Ibaraki Prefecture, Shirahoji 162 Shirane, Nippon Telegraph and Telephone Corporation, Ibaraki Telecommunications Research Institute (56) Reference JP-A-57-7115 A) JP 58-141246 (JP, A) JP 60-199890 (JP, A)

Claims (1)

[Claims] 1. The following general formula I: (In the formula, R ₁ represents an i-propyl group or a t-butyl group, and R ₁
Is an i-propyl group, R ₂ is a cyano group and R ₃ is hydrogen, and when R ₁ is a t-butyl group, R ₂ is hydrogen and R ₃ is a cyano group). An alkyl cyanophthalocyanine compound characterized by being obtained.