DE2164182C3 - Naphthopyrylium perchlorates and processes for their preparation and their use as sensitizers - Google Patents

Description

I Il

ClO ₄

(I) The invention relates to naphthopyrylium chlorate ίο of the general formula

in which R _{1 is} an alkyl radical with 1 to 9 carbon atoms, a phenyl or benzyl radical. a p-alkoxystyryl radical with 1 or 2 carbon atoms in the alkyl part or a p-halogen or p-carboxystyryl _{radical and R 2} a styryl radical, a p-alkoxy, 3,4-dialkoxy or 3.4.5-trialkoxystyrylresi with 1 or 2 each Carbon atoms in the alkyl part or a p-halostyryl radical or a 2 - (r / - pyrrolyl) äthenyl-. 2 - (. <- Thienyl) äthenyk 2- (u-furyl) äthenyi- or 2- (4'-alkoxynaphthyl) -äthenylrest with 1 or 2 carbon atoms in the alkyl part or in which R _{1 is} a hydrogen atom and R _{2 is} the phenyl or p-methoxystyryl radical or R ₁ and R ₂ denote the p-carboxystyryl or p-nitrostyryl radical.

2. Process for the preparation of naphthopyrylium perchlorates according to claim 1. characterized characterized in that one is known per se

a) 2-Hydroxy-1-naphthaldehyde with a ketone of the general formula

R ₁ CH ₂ COR, Hl)

in which R, has the meaning given and R, in the event that R, stands for a hydrogen atom. the phenyl or p-methoxystyryl radical and in the event that R _{1 stands} for a p-carboxystyryl radical or p-nitrostyryl radical, a p-carboxystyryl radical or p-nitroslyryl radical, in the presence of a mineral acid at a temperature of 15 to 35 C and that Rcaktionsprodu'-t obtained with perchloric acid or a perchlorate or that one

b) the reaction product from 2-hydroxy-1-naphthaldehyde and the ketone of the general formula! with an aldehyde! the uncommon formula

R ₄ CHO (III)

in the R. _t a phenol residue. p-alkoxy, 3.4-dialkoxy or 3.4.5-trialkoxyphenyl radical, each with 1 or 2 carbon atoms in the alkyl part. a p-Haiogenphenyl- or -4-Alkoxynaphthylrest with 1 or 2 carbon atoms in the alkyl part or the pyrrole)! -. Ihienyl- or Fuiylrcsi means at a temperature of 15 to 35 (let react further! And then the reaction product obtained is replaced with perchloric acid or a perchlorate.

ClO ₄

in which R _{1 is} an alkyl radical having 1 to 9 carbon atoms, a phenyl or benzyl radical. a p-Alkoxystyrylresi with 1 or 2 carbon atoms in the Alicyltei! or a p-halogen or p-carboxyslyryl _{radical and R 2} a styryl radical. a p-alkoxy-. 3.4-bialkoxy or 3.4,5-TriaIkoxystyrylrest each with 1 or 2 carbon atoms in the alkyl part or a p-Halostyrylrest or a 2 - (<i-pyrrolyl) -äthenyl-, 2-i.; - ThienyDäthenyl-, 2 - (< - Furyl) ethynyl or 2- (4'-alkoxynaphthyl) ethenyl radical with 1 or 2 carbon atoms in the alkyl part or in which R _{1 is} a hydrogen atom and R _{2 is} the phenyi- or p-methoxystyryl radical or R ₁ and R _{2 are} the p- Carboxystyryl or p-nitroslyryl radical and mean a process for their preparation and their use as a sensitizer for organic phosphites.

F.s are the most diverse organic photoconductors for use in electrophoresis recording materials known. Organic photo conductors are inorganic photoconductors in terms of transparency Flexibility, superior in film-forming properties and the like. Organic are particularly suitable Phololei'er without further ado for training more uniform, more transparent and often almost colorless photosensitive films on a layer support. The sensitivity of such organic photoconductors is, however, only several thousandths or Hundredths of inorganic photoconductors. like zinc oxide and selenium this valley thing looks troi / der The undisputed advantages of organic photoconductors are extremely disadvantageous in preventing them from becoming more widespread. Since the sensitivity of photoconductors as such is usually low. they usually become mixed with sensitizers, whereby their sensitivity maximum. im [-'all that it is inherent in the short-wave range of the visible spectrum is shifted to the longer-wave region of the spectrum. Though numerous organic Substances known as sensitizers to improve the sensitivity of photoconductors are, lad; no generally valid statement about meet their usability, since every organic sensitizer partly with advantages and partly with disadvantages is afflicted. Suitable known sensitizers are, for example, Kristallvuilctt and methylene blue. I 111, however, have a sufficiently high level of sensitivity

fts, both have to go to finals in large quantities / get what happens as a result of their strong identity has proven to be highly detrimental.

It has now been found. that you see the

<(■■

according to Naphihopyryliumperchloratc in the most advantageous Way as sensitizers to improve the chemical and optical sensitivity of have organic photoconductors used.

The naphthopyrylium perchlorates of the invention are suitable as sensitizers for common known organic photoconductors, such as polyvinyl carbazole, its derivatives and polyvinyl anthracene. The sensitizer is used in an amount of 0.01 to 2 percent by weight of the organic photoconductor. The sensitizer can be in the photoconductor solid form or preferably be added in dissolved form. If necessary, a synthetic resin, such as a polycarbonate. be used as a binder.

The properties of some naphthopyrylium perchlorals according to the invention were among others also tested against known sensitizers. The following tests were carried out:

A. By dissolving 23 g of chlorinated polyvinyl carbazole (with 0.5 chlorine units per carbazole ring) and 0.7 g of polycarbonate resin in a solvent mixture. consisting of 33 g monochlorobenzene and 6.3 g dichloroethane. and adding 0.5 g of diphenyl chloride to the resulting solution, a photosensitive coating solution was prepared. The resulting coating solution was admixed with a solution of the compound from Example 6 in dichloride, so that a solution was obtained which contained 5 mol of the sensitizer per gram of chlorinated polyvinyl carbazole In a manner applied to the surface of a substrate made of paper made electrically conductive, so that ¹ , a layer with a thickness, measured in the dry state, from 5 to 0.5 t was obtained Usually known We'se positively charged by corona discharge (about 6 kV) The charged electrophotographic recording material was then 2 to 4 seconds by reflection projection A light of 20 lux was exposed) against an original. The exposed electrophotographic recording material was finally developed with a clektrophotographic suspension developer, a sharp, high-quality reproduction of the original being obtained.

B. Dissolving 2.3 grams of brominated polyvinyl carbazole and 0.7 g of a polycarbonate resin in a mixed solvent consisting of 33 g of monochlorobenzene and 6.3 g of dichloroethane, and adding 0.5 g of diphenyl chloride to the resulting solution a coating solution prepared. The resulting coating solution became a solution of the compound of Example 5 was added in dichloroethane, so that a solution was obtained, the 5 ■ 10 "" mol of the Contained sensitizer per gram of brominated polyvinyl carbazole. The sensitizer-containing coating solution obtained After thorough mixing, aiii was carried out in the manner described under A applied a layer support, whataul the received electrophotographic recording material according to A charged helichlei and en) wickeil was. Here

a sharp, high quality reproduction of the original was obtained.

C. Electrophotographic recording materials were made in the manner described under A using the following inventive compounds No. 1 to 19 as Sensitizer and the known sensitizers I to IV prepared and according to A for copying purposes used.

Compound no.1 (example 6):

2- (p-methoxystyryl) -3-phenylnaphtho-

pyrylium perchlorate. Connection no.2 (example 5):

2- [ _; ;-( 4'-methoxynaphthyl) ethenyl] -

3-phenyinaphthopyrylium perchlorate, compound no.3:

2- (3'.4'-dimethoxystyryl) -3-phenylnaphtho-

pyrylium perchlorate. * o Connection no.4 (example 4):

2- (3 ', 4'-diethoxystyryl) -3-phenylnaphthopyryiium perchlorate,

Connection no.5:

2- (p-ethoxystyryl) -3-phenylnaphthopyrylium perchlorate.

Connection no.6:

2- [2 '- («- thienyl) ethenyl] -3-phenylnaphtho-

pyrylium perchlorate. Connection no.7 (example 3):

2- [2 '- (ii-pyrrolyl) ethenyl] -3-phenylnaphtho-

pyrylium perchlorate. Connection no.8 (example 1):

2- (p-Methoxystyryl) -3-isopropylnaphthopyrylium perchlorate.

Connection No. 9:

2- (p-methoxystyryl) -3-hexylnaphtho-

pyrylium perchlorate. Compound No. 10 (Example 2): 2.3-di (p-methoxystyryl) naphthopyrylium-

pcrchlorate.
Connection no.11:

2- (p-methoxystyryl) naphthopyrylium perchlorate,

Connection no.12:

2.3-di! P-nitrostyryl) naphthopyrylium perchlorate.

Connection no.13:

2.3-di (p-carboxystyryl) naphthopyrylium-

perchlorate,

Compound No. 14: 2-phenylnaphthopyryluniperchlorate.

Compound No. 15: 2- (3'.4 ', 5'-triethoxystyryl) -3-phenylnaphtho-

pyrylium perchloral. Connection no.16:

2- (3 ', 4'Diethoxystyryl) -3-octyl-ncphtho-

pyrylium perchlorate, compound no.17:

2- (p-methoxystyryl) -3-decylnaphtho-

pyryu perchlorate. Connection no. IS:

(,. 2.3-di (p-bromostyryl) naphihopyrylium perchlorate.

Connection Ni. 19:

2 - (. V.4'-Dimethoxystyi y \\ - 1 bcii / \ inaphlhopyryliunipcrclilor;:!.

Compound 1 Chrysoidin 3 R

Connection 1! Crystal violet

CH,

CHj CHj

Compound III Methylenviolctt

NH,

cn,

CH,

C ₂ H ₅

Compound IV Neumethvlblau

S.
Cl

CH.,

Il

CH,

164
5 182}
Connection no
4th 6th
Optimal
Bclichtunpswcrlc
H-ux. lake.)
33.5
36.5 wavelength
(/., "",) In niu
613
590 5 211
117
106
40 577
(586) 618
540 (600)
590 6th IIS 597 7th 90
420
330
180
18th
18th
63
190
50
1500
163
286
240 520
500
496
507
630
620
556
525
620
455
605
568
636 10 8th 9 10 Il 15th 12th Π 14th 20th 15th 16 17th 25th 18th 19th Connection I ...
Compound Il ...
Compound III. .
Compound IV ..

35

40

Note: The values for / "," _v were measured in a solution of the compound in question in diehloräthar. In Fi g. Fig. 4 is a spectral sensitivity curve of an electrophotographic recording material sensitized with Compound No. 8 in the visible light region of 470 to 640 m; shown. 5 shows the spectral sensitivity curve of an electrophotographic recording material sensitized with compound no. 10 in the range of visible light from 490 to 670 μm.

It should be noted that the one electrophotographic The sensitivity imparted to the recording material by a sensitizer is, the lower the optimal exposure values are, but with regard to the respective absorption maxima possibly a slightly worse value for the optimal exposure is accepted can.

The naphthopyrylium chlorates mentioned above gebeiicn general formula I are produced by that one in a known manner

a) 2-Hydroxv-l-naphthaldehyde with a ketor the allecmcincn t ormel

In the following table are the optimal exposure valuesc and the optimal wavelengths for the electrophotographic ones containing said sensitizers Recording material specified.

RiCH ₂ COR ₃

Connection no.

Optimal Beliehlungswert

(Lux. Sccl

143 142.5 93.5

Wavelength (/., “,, I in mi

586 600 607 in which R has the meaning given unc R ₃ in the event that R _{1 represents} a hydrogen atom, the phenyl or p-methoxystyryl radical and in the case that R _{1 represents} a p-carboxystyryl radical or p-nitrostyryl radical, a p -Carboxystyryl radical or p-Nitrostyryirest represents, in the presence of a mineral acid at a temperature of 15 to 35 ° C and the reaction product is treated with perchloric acid or a Pcrchlorat, or that one

b) the reaction product from the 2-hydroxy-1-naphthaldehyde and the general ketone

Formula II with an aldehyde of the general formula R ₄ CHO

in which R _{4 is} a phenyl radical, p-alkoxy, 3,4-dialkoxy or 3,4,5-trialkoxyphenyl radical, each with 1 or 2 carbon atoms in the alkyl part, a p-halophenyl or 4-alkoxynaphthyl radical with 1 or 2 carbon atoms in the Alkyl part or the pyrrolyl, thienyl or furyl radical means, allowed to react further at a temperature of 15 to 35 ° C. and then the reaction product obtained is admixed with perchloric acid or a perchlorate.

The 2-hydroxy-1-naphthaldehyde. Ketones of the formula II and aldehydes of the formula IH can be on the one hand readily prepared by conventionally known methods and, on the other hand, are commercially available available.

Procedures a) and b) can be used in one to dissolve the reaction oils and the reaction products suitable organic solvents. z. B. an alcohol, dioxane or tetrahydrofuran as well as combinations thereof. It is also preferable to use organic ones Acids such as formic acid and / or acidic acid.

The mineral acid used as the condensing agent is, in particular, hydrochloric acid. and preferably in an amount of 5 to 20 moles per mole of aldehyde used. Appropriately the reaction is ended by adding further 10 to 20 mol of mineral acid per mol Aldehyde.

In procedure a) you work with a molar ratio of 2-hydroxynaphthaldehyde to ketone Formula 11 of 1: 1; in procedure b) works man in the case that the radical R denotes a methyl radical, with a molar ratio reaction product of 2-hydroxy-1-naphthaldehyde and ketone of the general Formula II to aldehyde of the general formula III of 1: 2 and in the event that the Res! R, one other than a methyl radical means with a MoKcihällnis reactin product of 2-hydroxylnaphthaldehyde and ketone of the general formula II from 1: 1.

(HI

OCH ₁

cn,

CH,

CK) _a

1 g of 2-hydroxy-I-naphthaldehyde and 0.7 g of isobutyl ketone of _{the formula (CH 3} I ₂ CHCH _{2 COCH 3} were dissolved in a solvent mixture consisting of 40 ml of alcohol and 20 ml of formic acid, whereupon the resulting solution at room temperature with 5 ml Undiluted hydrochloric acid was added and left to stand for 12 hours

40

example 1

2 - ip - methoxystyryll - 3 - isoprop \ lnaphihop> rylium perchlorate the formula

Solution with a solution of 1.3 g of p-methoxybenzaldehyde of the formula

OHC

OCH ₁

in 20 ml of formic acid, to which 5 ml of 35% igci Hydrochloric acid had been added, whereupon the resulting reaction mixture oei Night was left. The resulting reaction product was then poured into cold 10% aqueous iigc perchloric acid solution poured in, whereby eir Precipitation farewell. The precipitate formed was filtered off and recrystallized from Lacetic acid 2.5 g of 2- (p-methoxystyryl) -3-isopropylnaphtho pyrylium perchlorate in the form of red-violet crystals from m.p. 185 to 187 ° C. were obtained.

Weight analysis for C ₂₅ H ₂₁ ClO ,, in percent:
Calculated . . C 66.0, H 5.0;
found .... C 66.3. H 4.93.

The compound dissolved in 1,2-dichloroethane. bcsai. an absorption maxima (A " _{1 (lv} ) at 540 ΐημ and 6 (X) ιτίμ its molar absorption coefficient (1) was 2.2 K) ⁴ and 1.2 ■ IO ⁴ . The IR spectrum of the compound is shown in FIG. 1 shown.

Example 2

2.3 - di (p - Melhoxyslyryllnaphlhopyryliumperchlo advice of formula

CH CH ^{/ y} / -OCH,

CH "CH -'S -.-- OCH,

CiO ₄

1 g of 2-hydroxy-l-naphthaldehyde and 0.7 g of methyl ethyl ketone of the formula CH ₁ CH ₂ COCH were dissolved in a solvent mixture consisting of 10 ml of tetrahydrofuran and 10 ml of formic acid, whereupon the resulting solution was dissolved in 5 ml of 35 ml at Raumiempcratu % hydrochloric acid was added and the mixture was left to stand overnight. The solution obtained was then treated with a solution of 2.5 g of p-methoxybenzaldehyde in 10 ml of formic acid and a further 5 ml of 35% hydrochloric acid and then left to stand overnight and processed. 2.5 g of violet crystals of 2,3-di- (p-Mcth oxystyryonaphthopyrylium chlorate with a temperature of 235 to 237 C were obtained.

Weight analysis for C ₁₁ H ₂₃ ClO ₇ in percent:
Calculated ... C 68.31. H 4.58;
found C 68.96. 11 4.4 «.

The compound dissolved in 1,2-dichloroethane. Besal an absorption maximum (at 597 /.,""J ηΐμ and Einei molar Fxtinktionskocffizientcn (. (2.5 · \ if. Since IR Spcktrum of the compound is g in F i. 2

509 620/20

Example 3
- pyrrolyl) ethenyl] - 3 - phenylnaphtho-

2 - [2 'pyrylium pcrchlorate of the formula

CH-CH

ClO ₄

2 g of 2-hydroxy-1-naphthaldehyde and 2 μ of phenylacetone the formula

■ f; CH ₂ COCH,

N
H

CHO

4 g I'.hn from

in 10 ml of formic acid and a further 5 ml of 3V hydrochloric acid and then left to stand overnight. The reagent mixture obtained was then treated and worked up in the manner described in Example 1, with
2 - Γ2 '- (.j - pyrrolyljäthenyl] - 3 ■ phenylnaph
pyrylium perchlorate in the form of purple crystal
Γ-. 225 C were obtained.

Weight analysis m percent for C ₂₅ II _1S ('INO ₄ :
Calculated ... C 67.03. Il 4.02. N 3.12,
found .... C 67.75. H 4.36. N 3.40.

The compound dissolved in 1.2-Uichlorälhan. possessed an absorption maxima (A ₁₁₁₁₁₁ I at 5Sb nv and at 618 mμ. The molar expansion coefficients (■) were 1.0 · Iff and 1.3 · K) ⁴ . The IR spectrum of the compound is shown in FIG. 3 shown.

Example 4

2- (3,4'-diethoxystyryl) -3-phcnylnaphthopyrylium perchlorate the formula

CH = CH-

OC ₂ H,

OC ₂ H,

1; 1

Λ /

ClO ₄

10

were dissolved in a solvent mixture consisting of 15 ml of dioxane and 15 ml of formic acid. 6 ml of 35% hydrochloric acid were then added to the resulting solution at room temperature became. 2 hours later, the resulting solution was treated with a solution of 2 g of n-pyrrole aldehyde of the formula

2 g 2-hydroxy-l-naphthaldehyde and 2 g phenyl acetone were in a solvent mixture consisting of 20 ml of dioxane and 15 ml of formic acid dissolved, and 6 ml of 35% hydrochloric acid were added to the resulting solution. After dit The resulting mixture was stirred for 2 hours, it was mixed with a solution of 2 g of 3,4-dihaloxybenzaldehyde the formula

OC ₂ H ₅

■ - OC ₂ H ₅

in 5 ml of formic acid and another 5 ml of 35% hydrochloric acid and then be Left to stand at room temperature overnight. The reaction mixture obtained was according to that in Example 1 described way treated and processed. wherein 4.5 g of 2- (3 ', 4'-diethoxystyry)) - 3-phenylnaphthopyrylium perchlorate in the form of reddish-violet egg crystals with a melting point of 185 to 187 ° C.

Weight analysis in percent for C ₁₁ H ₂₇ CIO ₇ :
Calculated ... C 68.0, H 4.94;
found .... C 68.88, H 4.72.

The compound, dissolved in 1,2-dichloroethane, had an absorption maximum (> _max ) at 613 μm and a molar extinction coefficient (O) of 5.7 × 10 ⁴ .

Example 5

2 - (4 '- methoxynaphthyl) ethyl - 3 - phenylnaphthopyrylium preclorate the formula

.ys

CH-CH

OCH ₁

ClO,

2 g of 2-hydroxy-1-naphtha! Dehyde and 2 g of phenyl acetone were in a solvent mixture. best iu-nd dissolved from 10 ml of dioxane and 15 ml of formic acid, whereupon the resulting solution at room temperature temperature with 5 ml of 35% hydrochloric acid and then left to stand at room temperature for 3 hours. The solution was then mi a solution of 2 g of 4-methoxy-1-naphthalene helmet the formula

OHC

OCH,

in 15 ml of formic acid and a further 10 ml of 35% hydrochloric acid. That received * The reaction mixture was then treated and worked up according to Example 4, with 4 g of 2- (4'-methoxy naphthy!) äthenyl - 3 - phenylnaphthopyrylium perchlorate in the form of bluish violet crystals with a temperature of 185 ° ( were obtained.

Weight analysis in percent door C ₃₂ H ₂₃ ClO ₃ :
Calculated ... C 71.30. H 4.27:
found .... C 72.00. H 4.50.

The compound, dissolved in 1,2-dichloroethane, had an absorption maximum (/. _Mov ) at 660 ma and a molar extinction coefficient (ι) of 3.1 · K) ⁴ .

Example 6

2- (p-melhoxystyryl) -3-phylnaphthopyrylium perchlorate the formula

CH = CH

OCH,

CIO ₄

2 g of 2-hydroxy-1-naphthaldehyde and 2 g of phenylaceion were in a solvent mixture consisting of 20 ml of dioxane and 15 ml of formic acid, dissolved, whereupon the resulting solution with 6 ml of 35%

Hydrochloric acid was added. 2 hours later the solution was mixed with a solution of 2 g p-anisaldehyde in 5 ml of formic acid and mixed with a further 6 ml of 35% hydrochloric acid and then left to stand at room temperature for a day and night. The reaction mixture obtained was then poured into a cooled 15% aqueous solution of chloric acid, whereby a precipitate parted. The precipitate formed was filtered off and recrystallized from acetic acid, wherein 1.5 g of 2- (p-methoxystyry]) -3-phenyinaphthopyrylium perchlorate were obtained in the form of reddish-purple crystals with a temperature of 154 "C.

Weight analysis in percent for C ₂₈ H ₂₁ ClO ₆ :
Calculated ... C 68.78, H 4.29;
found .... C 69.41. H 4.27.

The compound, dissolved in 1,2-dichloroethane, had an absorption maximum (/. ",") Of 586 ητίμ and a molar coefficient of expansion (0) of 7.0 · 10 ⁴ .

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1 Naphthopyrylium perchlorate of the general formula 3. Use of naphthopyrylium salts according to claim 1 as sensitizers for organic Photoconductor.