EP2588411A1

EP2588411A1 - Polysilanes of medium chain length and a method for the production of same

Info

Publication number: EP2588411A1
Application number: EP11730630.8A
Authority: EP
Inventors: Norbert Auner; Christian Bauch; Rumen Deltschew; Sven Holl; Javad MOHSSENI
Original assignee: Spawnt Private SARL
Current assignee: Spawnt Private SARL
Priority date: 2010-07-02
Filing date: 2011-07-04
Publication date: 2013-05-08
Also published as: KR101569594B1; CN103080006A; JP2013529591A; DE102010025948A1; WO2012001180A1; KR20130072237A; US20130216465A1

Abstract

The invention relates to polysilanes of medium chain length as pure compounds or a mixture of compounds, each with at least one direct Si-Si bond, the substituents of said polysilanes consisting exclusively of halogen and/or hydrogen, the medium chain length n thereof being greater than 3 and smaller than 50, preferably greater than 3 and smaller than 9 and particularly preferred being greater than 3 and smaller than 7, and the atomic ratio of substituent:silicon in the composition thereof being at least 1:1. The invention also relates to a method for the production of same.

Description

description

Polysilanes medium chain length and method for their

manufacturing

The present invention relates to polysilanes of medium chain length as pure compound or mixture of

Compounds each having at least one direct bond Si-Si, their substituents exclusively from halogen

and / or consist of hydrogen and in whose

Composition the atomic ratio substituent: silicon is at least 1: 1, and method for their preparation.

In the prior art, polysilanes are prepared by numerous methods, such as by heating gaseous chlorosilanes with or without reducing agent to relatively high temperatures (above 700 ° C). However, the resulting chlorinated polysilanes (PCS) have only a high proportion of short-chain, branched and / or cyclic molecules and are also contaminated with solvent / catalyst or substances from the reactor walls. Furthermore, in the methods mentioned in the prior art for

Production of polysilanes disadvantage that they do not demonstrate a particularly efficient production of polysilanes medium chain length in useful yields. Furthermore, the prior art lacks polysilanes, which because of their special properties will play an important role in future industrial processes.

The present invention is based on the object

Polysilanes medium chain length as a pure compound or Mixture of compounds each having at least one direct bond Si-Si whose substituents consist exclusively of halogen and / or hydrogen and in whose composition the atomic ratio substituent: silicon is at least 1: 1, and a process for their

Preparation to provide a particularly efficient representation of such polysilanes

to reach .

This object is achieved by a polysilane medium chain length with the characterizing features of claim 1 and a method having the characterizing features of claim 20.

The polysilanes according to the invention of medium chain length are characterized in their chemical properties by the presence of direct bonds Si-Si, whereby these substances have a strong affinity for oxygen and chlorine and are suitable for binding these elements. Thus, e.g. chlorinated oligosilanes too

Deoxygenation reactions used. The polysilanes of the invention are still due to their middle

Chain length of greater than 3 and less than 50, preferably greater than 3 and less than 9, more preferably greater than 3 and less than 7, completely soluble in suitable inert solvents and partially have a significant vapor pressure of above 1 Pa (less than 500 hPa) at 200 ° C, ie, well below their decomposition temperatures, which are typically above 250 ° C, what they are for the

Application suitable for the deposition of silicon from the gas or liquid phase. The vapor pressure is preferably above 1 hPa and below 1000 hPa at 200 ° C. Particularly noteworthy here is the property of all According to the invention polysilanes that from these due to their molecular composition by suitable processes, such as annealing at high temperatures, pure silicon can be obtained.

All polysilanes according to the invention also have in common that they disproportionate in the thermal treatment, that is, disintegrate into longer and shorter-chain products.

Preferred developments of the invention will be apparent from the

Subclaims 2 to 19. Thus, the brominated or hydrogenated polysilane is colorless to light yellow. The chlorinated polysilane is colorless to greenish yellow, intense orange or reddish brown.

The polysilanes of medium chain length are liquid or viscous to solid depending on their molecular structure.

However, polysilanes which are solids in pure form may also be completely or partially dissolved in liquid polysilanes.

The polysilanes expediently have a metal content of less than 1%.

For the deposition of crystalline silicon it is preferred to use polysilanes which are less than 2 atomic%.

Contain hydrogen.

For special liquid coating processes

Preferably, polysilanes are used which predominantly linear long chains and almost no short chain

contain branched chain and ring compounds. Here, the content of branch points of the short-chain Proportion based on the entire product, preferably less than 2%.

For deposition reactions at low temperatures, particular preference is given to using polysilanes whose substituents consist exclusively of hydrogen.

The substituents of the polysilanes preferably consist exclusively of halogen or of halogen and hydrogen.

The polysilanes of medium chain length can continue

Halogen substituents of several different halogens

contain .

For special liquid coating processes

Preferably used polysilanes whose average size of the backbone n = 8-20. Particular preference is given to using polysilanes whose average size of the skeleton after distilling off the short-chain fraction is n = 15-30.

Spectroscopic characterization: Polysilanes have a) only bands in their IR molecular vibrational spectra

Range smaller than 2400 wavenumbers, b) in RAMAN molecular vibration spectra only bands in the range less than 2300 wavenumbers,

Polysilanes whose substituents consist of fluorine possess a) in Si-NMR spectra significant product signals in the chemical shift range of 8 ppm to -40 ppm and / or from -45 ppm to -115 ppm, b) typical RAMAN intensities not outside the ranges 10 cm ^"1 to 165 cm ^{" 1} , 170 cm ^"1 to 240 cm ^{" 1} , 245 cm ^"1 to

360 cm ^"1 , 380 cm ^{" 1} to 460 cm ^"1 , and 480 cm ^{" 1} to 650 cm ^"1 and 900 cm ^{" 1} to 980 cm ^"1 own.

Polysilanes whose substituents are chlorine, have a) in ²⁹ Si NMR spectra significant product signals in the chemical shift range of 15 ppm to -10 ppm, from -25 ppm to -40 ppm and / or -65 ppm to -96 ppm. b) typical RAMAN intensities not outside the ranges 10 cm ^"1 to 165 cm ^{" 1} , 170 cm ^"1 to 240 cm ^{" 1} , 245 cm ^"1 to

360 cm ^"1 , 380 cm ^{" 1} to 460 cm ^"1 , and 480 cm ^{" 1} to 650 cm ^"1 .

Polysilanes whose substituents are bromine have a) in ²⁹ Si NMR spectra their significant product signals in the chemical shift range from -10 ppm to -42 ppm, from -46 ppm to -55 ppm and / or -63 ppm to -96 ppm , b) typical RAMAN intensities not outside the ranges 10 cm ^"1 to 150 cm ^{" 1} , 155 cm ^"1 to 350 cm ^{" 1} , at 390 cm ^"1 to 600 cm ^{" 1} and at 930 cm ^"1 to 1,000 cm ^{" 1} .

Polysilanes whose substituents consist of iodine, have a) in ²⁹ Si NMR spectra significant product signals in chemical shift range from -20 ppm to -55 ppm, from -65 ppm to -105 ppm and / or from -135 ppm to -181 ppm, b) typical RAMAN intensities not outside the ranges 10 cm ^-1 to 150 cm ^-1 , 155 cm ^-1 to 600 cm ^-1 and at 930 cm ^-1 to 1000 cm ^"1 .

Polysilanes whose substituents are hydrogen, have a) in ²⁹ Si NMR spectra significant product signals in the chemical shift range of -65 ppm to -170 ppm, b) in RAMAN molecular vibration spectra characteristic band in the range of 2000-2200 wavenumbers and in the range from 2000 to 1100 no gangs.

IR measurements were taken on a FT / IR-420 spectrometer from Jasco Corp. obtained as KBr pellet.

Liquids were made with preformed KBr pellets

sucked up or measured between NaCl plates.

Raman molecular vibration spectra were on a

Spectrometer XY 800 from Dilor with tunable

Laser excitation (T-sapphire laser, pumped by Ar ion laser) as well as confocal Raman and Lumineszenzmikroskop, with liquid nitrogen cooled CCD detector, measuring temperature equal to room temperature, excitation wavelengths in the visible spectral range, u. a. 514.53 nm and 750 nm, measured.

²⁹ Si NMR spectra were recorded on a 250 MHz type

Bruker OPX 250 with pulse sequence zg30 recorded and against tetramethylsilane (TMS) as external standard [δ ( ²⁹ Si) = 0.0] referenced. The acquisition parameters are: TD = 32k, AQ = 1.652 s, Dl = 10 s, NS = 2400, OlP = -40, SW = 40O.

The inventive method for the preparation of

Polysilanes of medium chain length Si _n 2n + 2 and Si _n 2n with n greater than 3 and less than 50, preferably greater than 3 and less than 9, more preferably greater than 3 and less than 7, and X = F, Cl, Br, I and / or H is thereby characterized in that it contains one or more of the synthesis steps described below. The individual variants are below

reproduced.

In a first variant, the polysilanes are through

plasma-assisted synthesis of halosilanes.

In a second variant, the polysilanes are obtained by plasma-assisted synthesis of halosilanes, where halogen is bromine.

In a third variant, the polysilanes are obtained by plasma-assisted synthesis of H-silanes and / or H-oligosilanes.

In a fourth variant, the polysilanes are obtained by plasma-assisted synthesis of halogenated oligosilanes, with particular preference being given to using halogenated di- and trisilanes.

In a fifth variant, the polysilanes are prepared by plasma-assisted synthesis of mixtures which also contain organically substituted silanes and / or oligosilanes.

receive. For example, methylchlorosilanes are used for this purpose. During the plasma-assisted synthesis, preference is given to using a mixing ratio of halosilane: hydrogen of from 1: 0 to 1: 2 and in a pressure range of from 0.8 to 10 hPa.

In a sixth variant, the polysilanes are through

Hydrohalogenation with HCl and / or HBr for cleavage of polysilanes greater chain length obtained. In this case, preference is given in a pressure range from 1 bar to 43 bar

worked. Hydrohalogenation may be assisted by catalysts such as ammonium salts.

In a seventh variant, the polysilanes by catalytic coupling of disilanes and / or trisilanes with Organylphosphonium- and / or -ammoniumsalzen as

Catalysts obtained. This corresponds to one

Disproportionation reaction, whereby short-chain polysilanes are formed as by-products.

In an eighth variant, the polysilanes are through

Wurtzkupplung of lower halosilanes (such as disilanes and / or trisilanes) with alkali metals and / or magnesium. Especially preferred are activated metals, e.g. Rieke magnesium.

In a ninth variant, the polysilanes are through

Ring opening polymerization of cyclosilanes (Si _n X2n), where n is preferably 4.5 and / or 6.

In a tenth variant, the polysilanes are through

Coupling obtained by dehydrohalogenation. This

corresponds to a polycondensation with elimination of

Hydrogen halide molecules. In an eleventh variant, the polysilanes are through

dehydrogenative coupling of hydrogenated and / or partially hydrogenated silanes with transition metal complexes obtained.

In a twelfth variant, the polysilanes are through

Hydrogenation of polysilanes medium chain length obtained. For this purpose, preference is given to using halogenated polysilanes. For the hydrogenation of the polysilane, metal or metalloid hydrides are preferably used.

The reactor parts in which the above reactions take place are at a temperature of -70 ° C to 500 ° C,

especially -20 ° C to 280 ° C, held.

In a thirteenth variant, the polysilanes are obtained by pyrolysis of polysilane by a

Disproportionation and isolation of the polysilanes of the invention takes place from the vapor phase. In this case, preference is given to working in a pressure range of 10-1013 hPa.

In a fourteenth variant, the polysilanes are obtained by thermolytic chain extension on contact materials. It is after disproportionation of

Starting material preferably the longer-chain fraction isolated from the product mixture.

In a fifteenth variant, the polysilanes are obtained by thermal reaction of silicon with S1X. ₄

In the following, various aspects of the invention will be explained with reference to embodiments and a figure: FIG. 1 shows a Si-NMR spectrum of a

Isomeric mixture of chlorinated pentasilanes.

Exemplary embodiments:

1st embodiment: Synthesis of PCS: A mixture of 500 sccm of H2 and 500 sccm of S1CI ₄ (1: 1) is transformed into a

Reactor introduced from quartz glass, wherein the process pressure in the range of 1.6-1.8 hPa is kept constant. The gas mixture is then passed through a

High-frequency discharge in the plasma state, wherein the formed chlorinated polysilane is deposited on the cooled (20 ° C) quartz glass walls of the reactor. The radiated power is 400 W. After 2 hours, the yellow to orange-yellow product is removed by dissolving in little SiCl ₄ from the reactor. After removal of the SiCl ₄ under vacuum 91.1 g of polysilane remain in the form of an orange-yellow viscous mass. The average molecular weight is determined by cryoscopy to be about 1700 g / mol, which corresponds to the chlorinated polysilane (SiCl 2) _n or Si _n Cl _2n + 2 having an average chain length of about n = 17 for (SiCl 2) _n or ca. n = 16 for Si _n Cl 2 _n +2.

2nd Exemplary Embodiment: Plasma Synthesis of PCS and

subsequent thermolysis: A mixture of 300 sccm of H2 and 600 sccm of SiCl ₄ (1: 2) is introduced into a quartz glass reactor, the process pressure being kept constant in the range from 1.5 to 1.6 hPa. The gas mixture is then by a high-frequency discharge in the

transferred plasma state, wherein the

chlorinated polysilane deposited on the cooled (20 ° C) quartz glass walls of the reactor. The

radiated power is 400W. After 4 hours will the orange-yellow product is removed from the reactor by dissolving in a little S 1 Cl ₄ . After removal of the S 1 Cl ₄ under vacuum, 187.7 g of chlorinated polysilane remain in the form of an orange-yellow viscous mass. The average molecular weight is determined by cryoscopy and is approximately 1400 g / mol, which corresponds to the chlorinated polysilane (SiCl 2) _n or Si _n Cl 2 _{n +} 2 having an average chain length of about n = 14 for (SiCl 2) _n or ca. n = 13 for Si _n Cl 2 _{n +} 2 corresponds. A 50-60% solution of this Polychlorsilangemisches with a

average molecular formula of Si _n Cl _2n (0n = l 8) in S 1 CI ₄ is placed in a glass container and heated at 300 to 500 mbar pressure within 2 to 3 h at 300 ° C. Thereafter, the pressure is gradually reduced to finally 10 mbar and heated to 900 ° C in the course of 3 h. Finally, the temperature is left at 900 ° C for 1 h. The vapors emerging during the thermal decomposition of the polychlorosilane mixture are condensed out in a cold trap cooled with liquid nitrogen. The polychlorosilane mixture converted to a solid, highly crosslinked chlorinated polysilane (chloride-containing silicon) of the empirical formula SiClo, os to SiClo, o7 and short-chain chlorosilanes. After completion of the reaction, the container was allowed to cool and the solid product was taken out. Yields based on the

Starting material: 10-15 mass% SiClo, os to SiClo, o7 and 85-90 mass% short-chain chlorosilanes (diluent not included), with about 35 ~ 6 an

OCS according to the invention are included. By distillation, a fraction with predominantly n = 5 is isolated. It can be seen clearly in the ²⁹ Si NMR spectrum (FIG. 1) that it is a mixture of isomers (3 compounds) of the chlorinated pentasilanes. 3rd embodiment: plasma synthesis of PCS and

subsequent chlorination: A mixture of 200 sccm of H2 and 600 sccm of SiCl ₄ vapor (1: 3) is introduced into a quartz glass reactor, the process pressure being kept constant in the range of 1.50-1.55 hPa. The gas mixture is then transferred by a high-frequency discharge in the plasma-shaped state, wherein the

radiated power is 400W. After 2h 9min, the orange-yellow product is removed from the reactor by dissolving in a little SiCl ₄ . After removal of the SiCl ₄ under vacuum, 86.5 g of chlorinated polysilane remain in the form of an orange-yellow viscous mass. The average molecular weight is determined by cryoscopy and is about 1300 g / mol, which is for the chlorinated polysilane (SiCl2) _n or Si _n Cl2 _n +2 a mean chain length of about n = 13 for (SiCl2) _n or ca n = 12 for Si _n Cl 2 _n +2. 80 g of a chlorinated polysilane obtained in this way are mixed with 36.5 g

Si ₂ Cl6 diluted and in a closed apparatus with vigorous stirring at a temperature of 100 - 131 ° C for 24.5 hours so supplied with chlorine gas, that the pressure does not rise above 1213 hPa. After that will

fractionated distilled and, after separation of Si _n Cl2 _n +2 with n = 1 - 3, a residue of 9.25 g obtained, which consists of 2 ⁹ Si spectroscopic analysis mainly of several neo-chlorosilanes and the iso-Si ₄ Clio.

The chain length refers to the number of directly interconnected silicon atoms in a compound.

As used herein, the term "average chain length" those compounds in which 3 <n <50, preferably 3 <n <9, more preferably 3 <n <7.

The term longer-chain used here refers to those compounds in which n> 3. Where n is the

Number of Si atoms bonded directly to each other.

"Almost none" means that less than 2% is contained in the mixture.

By "predominantly" it is meant that the component in question is more than 50% contained in the mixture.

"Exclusively" should mean that much less

Contaminants are present in the mixture than is usual at high levels of purity for fine chemicals (e.g.,> 99%). Therefore, here is meant a purity of at least 99.9%.

"Inert solvents" are solvents

understood that under standard conditions do not react spontaneously with the (eg halogenated) polysilane medium chain length (hereinafter called "polysilane") (such as SiCl ₄ , benzene, toluene, paraffin, etc.).

The polysilane preferably meets the requirements for

Applications in semiconductor technology, particularly preferably those, as are common in photovoltaics.

Depending on the variant implemented, monosilanes can be used as starting materials for the process according to the invention

and / or polysilanes find use. Monosilanes in the sense of the process according to the invention are compounds of the type H _n SiX ₄ - _n (X = F, Cl, Br, I; n = 0-4), polysilanes compounds of the type Si _n X 2 n and / or Si _n X 2 n + 2 (X = F, Cl, Br , I and / or H) and mixtures thereof.

Claims

claims

1. polysilanes medium chain length as a pure compound or mixture of compounds with at least

a direct bond Si-Si, their substituents

consist of halogen and / or hydrogen

and in their composition the atomic ratio

Substituent: silicon is at least 1: 1,

characterized in that a) the average chain length is greater than 3 and less than 50, preferably greater than 3 and less than 9, more preferably greater than 3 and less than 7, b) this is soluble in suitable inert solvents

c) these are suitable as starting materials for silicon deposition, d) these oxygen and chlorine-binding properties

e) these decompose on thermal treatment in longer and shorter-chain products.

2. polysilanes medium chain length according to claim 1, characterized in that they are in IR molecular vibration spectra only bands in the range

have less than 2400 wavenumbers.

3. polysilanes medium chain length according to claim 1 or 2, characterized in that they are in RAMAN molecular vibration spectra only bands in the range

have less than 2300 wavenumbers.

4. Polysilanes medium chain length according to one of

preceding claims, characterized in that a) the halogen is fluorine, b) they have their significant product signals in the chemical shift range from 8 ppm to -40 ppm and / or from -45 ppm to -115 ppm in ²⁹ Si NMR spectra and c) they do not have typical RAMAN intensities outside

the ranges 10 cm ^-1 to 165 cm ^-1 , 170 cm ^-1 to 240 cm ^-1 ,

245 cm ^"1 to 360 cm ^{" 1} , 380 cm ^"1 to 460 cm ^{" 1} , and 480 cm ^"1 to 650 cm ^{" 1} and 900 cm ^"1 to 980 cm ^{" 1} own.

5. Polysilanes medium chain length according to one of

Claims 1 to 3, characterized in that a) the halogen is chlorine, b) in 29Si NMR spectra their significant product signals in the chemical shift range of 15 ppm to -10 ppm, from -25 ppm to -40 ppm and / or -65 ppm to -96 ppm

and c) they do not have typical RAMAN intensities outside

the areas 10 cm ^"1 to 165 cm ^{" 1} , 170 cm ^"1 to 240 cm ^{" 1} ,

245 cm ^"1 to 360 cm ^{" 1} , 380 cm ^"1 to 460 cm ^{" 1} , and 480 cm ^"1 to 650 cm ^{" 1} own.

6. Polysilanes medium chain length according to one of

Claims 1 to 3, characterized in that a) the halogen is bromine, b) in ²⁹ Si NMR spectra their significant product signals in the chemical shift range from -10 ppm to -42 ppm, from -46 ppm to -55 ppm and / or -63 ppm to -96 ppm

and c) they do not have typical RAMAN intensities outside

the areas 10 cm ^-1 to 150 cm ^-1 , 155 cm ^-1 to 350 cm ^-1 , 390 cm ^-1 to 600 cm ^-1 and 930 cm ^-1 to 1000 cm ^-1 have.

7. Polysilanes medium chain length according to one of

Claims 1 to 3, characterized in that a) the halogen is iodine,

29

b) they have their significant product signals in the chemical shift range from -20 ppm to -55 ppm, from -65 ppm to -105 ppm and / or from -135 ppm to -181 ppm in Si-NMR spectra and c) they are typical RAMAN Intensities not outside

the areas 10 cm ^-1 to 150 cm ^-1 , 155 cm ^-1 to 600 cm ^-1 and at 930 cm ^-1 to have 1000 cm ^-1 .

8. polysilanes medium chain length according to one of

Claims 1 to 3, characterized in that a) the substituents consist of hydrogen, b) they have their significant product signals in the chemical shift range from -65 ppm to -170 ppm in Si NMR spectra and c) they have a Raman molecular vibration spectra

have characteristic bands in the range of 2000-2200 wavenumbers and in the range of 2000 to 1100 no bands.

9. polysilanes medium chain length according to one of

preceding claims, characterized in that they are almost no short-chain branched chains

and rings, wherein the content of branch points of the short-chain portion based on the total

Product mixture is less than 2%.

10. polysilanes medium chain length according to one of

Claims 1 to 8, characterized in that

they contain a high content of short-chain branched chains and rings, wherein the content of branching points of the short-chain fraction based on the total

Product mixture is greater than 2%, preferably greater than 10%.

11. polysilanes medium chain length according to one of

preceding claims, characterized in that they halogen substituents of several different halogens

contain .

12. polysilanes medium chain length according to one of

preceding claims, characterized in that their substituents consist exclusively of halogen or halogen and hydrogen.

13. Polysilanes medium chain length according to one of

preceding claims, characterized in that they contain predominantly linear long chains.

14. polysilanes medium chain length according to one of

preceding claims, characterized in that the average size of the backbone of the polysilanes

n = 8-20.

15. Polysilanes medium chain length according to one of

after distilling off the short-chain polysilanes n = 15-30.

16. polysilanes medium chain length according to one of

preceding claims, characterized in that they are viscous to firm.

17. polysilanes medium chain length according to one of

preceding claims, characterized in that they have no chlorinated polysilane or a greenish yellow to intense orange or reddish brown color and are colorless to yellow as brominated or hydrogenated polysilane.

18. polysilanes medium chain length according to one of

preceding claims, characterized in that they are completely soluble in suitable inert solvents.

19. polysilanes medium chain length according to one of

preceding claims, characterized in that they contain less than 2 atomic% of hydrogen.

20. A process for the preparation of polysilanes of medium chain length Si _n 2n + 2 and Si _n 2n with n greater than 3 and less than 50, preferably greater than 3 and less than 9, more preferably greater than 3 and less than 7, and X = F, Cl, Br, I and / or H according to any one of the preceding claims, characterized in that it comprises one or more of the following synthetic steps: a) plasma-assisted synthesis of halosilanes, b) plasma-assisted synthesis of halosilanes, wherein

Halogen is bromine, c) plasma-assisted synthesis of H-silanes and / or

H-oligosilanes, d) plasma-assisted synthesis of halogenated oligosilanes, particular preference being given to using halogenated di- and trisilanes, e) plasma-assisted synthesis of mixtures which also contain organically substituted silanes and / or oligosilanes, f) hydrohalogenation for the cleavage of polysilanes

with HCl and / or HBr, g) catalytic coupling of disilanes and / or trisilanes with Organylphosphonium- and / or ammonium salts, h) Wurtzkupplung of lower halosilanes with

Alkali metals and / or magnesium, i) ring-opening polymerization of cyclosilanes (Si _n X 2n), j) coupling by dehydrohalogenation, k) dehydrogenative coupling of partially hydrogenated silanes with transition metal complexes,

1) hydrogenation of polysilanes of medium chain length, m) pyrolysis of polysilanes, n) thermolytic chain extension on contact materials, o) thermal conversion of silicon with SiX ₄ .

21. The method according to claim 20, characterized in that metal or metalloid hydrides are used in the hydrogenation of the polysilane medium chain length.

22. The method according to claim 20, characterized in that in the case of plasma-assisted synthesis with a

Mixing ratio of halosilane: hydrogen from 1: 0 to 1: 2 is worked.

23. The method according to claim 20, characterized in that is carried out during the plasma-assisted synthesis in a pressure range of 0.8-10 hPa.

24. The method according to claim 20, characterized in that is carried out during the pyrolysis in a pressure range of 10-1013 hPa.

25. The method according to claim 20, characterized in that during the hydrohalogenation in a pressure range of

1 bar to 43 bar is worked.

26. The method according to claim 20, characterized in that the reactor parts at which the reaction takes place, at a temperature of -70 ° C to 500 ° C, in particular -20 ° C to 280 ° C, are maintained.

27. The method of claim 20, wherein after

plasma-assisted synthesis of PCS is treated with thermolysis.

28. The method of claim 20, wherein after

plasma-assisted synthesis of PCS is chlorinated.