JPH0751705B2 - Dithiolene-type organometallic complex and method for producing the same, thin film and method for producing the same - Google Patents

Description

The present invention relates to a novel dithiolene-type organometallic complex, a method for producing the same, a thin film containing the complex, and a method for producing the thin film.

[Conventional technology]

Conventionally, dithiolene-type organometallic complex derivatives include bis (dithiobenzyl) nickel, bis (4-dimethylamino-dithiobenzyl) nickel, bis (4-diethylamino-dithiobenzyl) nickel, bis (4-dimethoxy-dithiobenzyl). Nickel, bis (1,2-dithiophenolate) nickel-tetra-n-butylammonium, bis (4-methyl-1,2-dithiophenolate) nickel-tetra-n-butylammonium, bis (3,4,
5,6-Tetramethyl-1,2, -dithiophenolate) nickel-tetra-n-butylammonium, bis (3,4,5,
6-Tetrachloro-1,2-dithiophenolate) nickel-tetra-n-butylammonium and the like are known. Since these have absorption in the oscillation wavelength region of a semiconductor laser, they are used as an organic recording material for optical discs. It is utilized (Japanese Patent Laid-Open No. 57-195336, etc.). Further, since this complex acts as a singlet oxygen quencher, it is used as an additive for improving the light resistance of recording materials having poor stability such as cyanine dyes (JP-A-59-59).
185694 publication). When these complexes are used in the organic recording material for optical discs, it is desired to make the recording layer as thin as possible in order to increase the recording sensitivity.

[Problems to be Solved by the Invention]

As a method for obtaining an organic thin film, there are spin coating of a solution and a polymer dispersed film, vacuum deposition, etc., but it is difficult to obtain a homogeneous film by any method, and a film without defects such as pinholes can be obtained. In order to obtain it, a certain thickness is required, which is not preferable. Therefore, since a uniform film without defects can be obtained, the film thickness can be controlled in the molecular order, and the orientation state of the molecules can be controlled, the organic thin film can be formed by the Langmuir-Bloget method (hereinafter, referred to as LB (Abbreviated as “method”) is desirable.

However, it has been found that the above-mentioned conventionally known dithiolene-type organometallic complex derivative cannot form an organic thin film by the LB method.

The present invention provides a dithiolene-type organometallic complex that can be formed by the LB method, a method for producing the same, and a thin film containing the compound.

[Means for Solving the Problems]

The dithiolene-type organometallic complex according to the present invention has the general formula (I): (In the formula, M represents Ni, Pt or Pd, and R ¹ , R ² , R ³ and R
⁴ represents an alkyl group or a hydrogen atom, at least one of which is an alkyl group having 3 or more carbon atoms and may be the same or different.

Since the dithiolene-type organometallic complex is a hydrophobic, insoluble compound, it generally causes aggregation and does not form a monomolecular film on the water surface, but as represented by the general formula (I), R ¹ , R ^When at least one of ² , R ³ and R ⁴ is a bulky alkyl group having 3 or more carbon atoms, particularly a branched alkyl group, the above aggregation is suppressed and a monomolecular film can be formed. At this point, in the general formula (I), R ¹ , R
^It is particularly preferable that all of ² , R ³ and R ⁴ are bulky alkyl groups having 3 or more carbon atoms, especially branched alkyl groups.

Specific examples of the dithiolene-type organometallic complex of the present invention include:
Bis (4,4'-di-tert-butyl-dithiobenzol) nickel, bis (4-tert-butyl-dithiobenzol) nickel, bis (4,4'-di-isopropyl-dithiobenzyl) nickel, bis (4-isopropyl -Dithiobenzyl) nickel, bis (4,4'-di-isobutyl-dithiobenzyl) nickel, bis (4-isobutyl-dithiobenzyl) nickel, bis (4,4'-di-isopentyl-dithiobenzyl) nickel, bis (4-isopentyl-dithiobenzyl) nickel, bis (4,4'-di-neopentyl-dithiobenzyl) nickel, bis (4-eopentyl-dithiobenzyl) nickel, etc., and platinum and palladium are similar. .

The dithiolene-type organometallic complex can be produced by reacting a benzoin compound with phosphorus sulfide and then reacting with nickel, palladium or platinum metal halide or potassium metal halide. As the benzoin compound, a compound containing 50 to 100 mol% of an alkyl-substituted benzoin having an alkyl group having 3 or more carbon atoms is used.

The above-mentioned benzoin compound has the general formula (II) (Wherein, R ⁵ and R ⁶ are hydrogen or a substituent such as an alkyl group having 3 or more carbon atoms, and these may be the same or different), and a benzaldehyde compound It can be obtained by benzoin condensation in the presence of potassium cyanide.

Examples of the benzaldehyde compound include benzaldehyde,
There are p-methylbenzaldehyde, p-ethylbenzaldehyde, p-dimethylaminobenzaldehyde, p-diethylaminobenzaldehyde and the like, and as the benzaldehyde having an alkyl group having 3 or more carbon atoms, p-te
There are rt-butylbenzaldehyde, p-isopropylbenzaldehyde, p-isobutylbenzaldehyde, p-isopentylbenzaldehyde and the like.

The dithiolene-type organometallic complex is a journal of
The American Chemical Society (Jounal of
the American Chemical Society) 87, 3583-359
Schrauzer, shown on page 2 (1965)
It can be manufactured according to these methods. That is, the benzoin compound represented by the general formula (II) is used together with an excess amount (particularly, about 1.5 times by mol of the compound) of P ₂ S ₅ and, if necessary, (NH ₄ ) ₂ SO ₄ , such as dioxane. After refluxing in an organic solvent to form a thiophosphoric acid ester corresponding to the above compound, a dithiolene-type organic metal is prepared by adding about 1/2 mol of a metal halide or potassium metal halide of the above compound and refluxing. A complex can be obtained. Here, as the benzoin compound represented by the general formula (II), an alkyl-substituted benzoin having an alkyl group having 3 or more carbon atoms (in the general formula (II), R ⁵ or R ₆
At least one of which is an alkyl group having 3 or more carbon atoms) is used in an amount of 50 to 100 mol%. In particular, the alkyl-substituted benzoin is preferably one in which R ⁵ and R ^{6 in} the general formula (II) are alkyl groups having 3 or more carbon atoms. As the metal halogen compound, nickel chloride (NiC
l ₂ ), palladium chloride (PdCl ₂ ), platinum chloride (PtCl ₂ ), and other metal chlorides, and the potassium metal halides include potassium chloroplatinate (K ₂ PtCl ₄ ), potassium nickel chloride. Examples thereof include (K ₂ NiCl ₄ ), potassium chloropalladate (K ₂ PdCl ₄ ), and the like, and potassium chloride metal oxides. Such metal halides or potassium metal halides may be hydrates.

The dithiolene-type organometallic complex thus obtained is
After the reaction, a precipitate is formed, which can be purified by washing with acetone or the like and then recrystallizing from ethyl acetate or the like.

The thin film of the dithiolene-type organometallic complex is formed by spreading the dithiolene-type organometallic complex on the sub-phase and transferring it onto the substrate while controlling the surface pressure. It is obtained by moving to. In the monolayer film accumulation method, transfer to the substrate is performed by the vertical dipping method,
It can also be performed by a horizontal attachment method or the like. The LB method is well known as one of the monolayer accumulation methods.

In the present invention, as a substrate for forming a thin film such as an LB film, there are inorganic glasses such as quartz glass and borosilicate glass and those on which a metal is vapor-deposited, or those on which a metal oxide is sputtered. Although used, the surface thereof may be either hydrophilic or hydrophobic.

When forming a thin film of a dithiolene-type organometallic complex by the LB method, an amphipathic film-forming substance having a long-chain alkyl group having about 10 to 24 times the number of carbon atoms may be added and formed. Examples of the film-forming substance include fatty acids such as stearic acid, aliphatic alcohols such as stearyl alcohol, and fatty acid ethers such as methyl stearate. The mixing ratio of the dithiolene-type organometallic complex and the film-forming substance is
It is preferably about 1/1 to 1/20 (molar ratio), and in order to suppress the decrease in optical density due to dilution, it is desirable that the ratio of the film-forming substance is as small as possible.

〔Example〕

 Example 1 The present invention will be described in more detail with reference to Examples below.

Using 40 g of 4-tert-butylbenzaldehyde and 7.0 g of KCN and using 240 ml of N, N-dimethylformamide as a solvent, 90 ° C.
The reaction was carried out for 3 hours to obtain 4,4'-di-tert-butylbenzoin 7.0 g. The resulting 4,4'-di-tert
-Butylbenzoin 5.0 g to P ₂ S ₅ 5.1 g, (NH ₄ ) ₂ SO ₄ 3.1 g
And refluxed in dioxane for 2 hours. After cooling and filtering, add 5.5 g of NiCl ₂ · 6H ₂ O dissolved in 60 ml of water to the filtrate and add 2
Reflux for hours. The formed precipitate was washed with acetone and recrystallized from ethyl acetate to give dark green needle crystals of bis (4,4′-di-tert-butyl-dithiobenzyl) nickel (hereinafter abbreviated as Ni (TBSB) ₂ ). 2.1 g was obtained. Its thermal decomposition temperature is about 340 ° C., and its ¹ H-NMR spectrum and IR spectrum (KBr method) are shown in FIGS. 1 and 2, respectively. ^{The 1} H-NMR spectrum was obtained by dissolving a sample in deuterated chloroform and using trimethylsilane as a standard substance. In FIG. 1, the peak at 1.3 ppm is due to hydrogen in the methyl group, and the peak around 7.3 ppm is due to hydrogen in the benzene ring. In Fig. 2, the absorption at 2950 cm ^-1 is based on the C—H bond of the methyl group,
The absorptions at ^-1 , 1140 cm ^-1 and 880 cm ^-1 are absorptions characteristic of the nickel dithiolene complex.

Next, using the Ni (TBSB) ₂ obtained above, a thin film was formed using an HBM type LB film forming apparatus manufactured by Kyowa Interface Science Co., Ltd.

That is, a solution of Ni (TBSB) ₂ in chloroform (concentration 0.1mmol /) obtained above was developed on pure water at a water temperature of 15 ° C and compressed at a compression speed of 20cm ² / min. A surface pressure-molecule occupied area curve (hereinafter, abbreviated as FA curve) was obtained.

Next, when a hydrophobically treated glass substrate was moved up and down at 10 mm / min under a constant surface pressure of 20 mN / m, Ni (TBSB) ₂ on the water surface
The monomolecular film could be accumulated on the glass substrate as a Langmuir-Blodiet film (Y film). The absorption spectrum of the obtained film is shown in FIG.

Comparative Example 1 Bis (dithiobenzyl) nickel, bis (4-dimethylamino-dithiobenzyl) nickel, bis (4-diethylamino-dithiobenzyl) nickel and bis (4,4 ′)
-Dimethoxy-dithiobenzyl) nickel was developed on the water surface under the same conditions as in Example 1 and the F-A curve was measured. In any case, no rising of the F-A curve was observed, and the monomolecular film was Not formed.

〔The invention's effect〕

The dithiolene-type organometallic complex derivative according to claims 1 to 3 or obtained by claim 4 is novel, and this compound is
According to the LB method, a thin film according to claim 5 of molecular order can be obtained. This thin film is useful as a recording layer of an optical recording medium.

[Brief description of drawings]

FIG. 1 is a diagram showing the ¹ H-NMR spectrum of Ni (TBSB) ₂ .
FIG. 2 shows the IR spectrum of Ni (TBSB) ₂ , FIG. 3 shows the F-A curve of Ni (TBSB) ₂ , and FIG.
FIG. 3 is a diagram showing an absorption spectrum of a (TBSB) ₂ Langmuir-Blodiet film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07F 15/04 9155-4H // B05D 1/20 6804-4D G11B 7/24 516 7215-5D ( 72) Inventor Ritsuko Obata 48 Wadai, Tsukuba-shi, Ibaraki Hitachi Chemical Co., Ltd. Tsukuba Development Laboratory (56) References JP 61-225192 (JP, A) JP 61-277492 (JP, A) JP-A-2-264787 (JP, A)

Claims (1)

[Claims] 1. A general formula (I) (In the formula, M represents Ni, Pt or Pd, and R ¹ , R ² , R ³ and R ⁴
Represents a tert-butyl group), and is produced by the LB method, which comprises a dithiolene-type organometallic complex.