FR2655655A1 - Process for the preparation of polysilthiophenediyl and polymers obtained as a result of this process - Google Patents

Abstract

A process for the preparation of polysilthiophenediyl which consists in carrying out a polycondensation reaction by reacting: - a reactant (a) of formula: in which R1 and R2 = alkyl or phenyl radical and m1 = 1 to 6, with - a reactant (b) of formula: Br-A-Br in which or with m2 = 1 to 3. The invention also relates to the polysilthiophenediyls obtained as a result of this process, of formula: in which n = 2 to 1000. These polysilthiophenediyls can be employed especially in electrical and magnetic applications.

Description

 The present invention relates to a process for producing polysilthiophenediyls. It also relates to polysilthiophenediyls that are obtainable by said method.

 In order to obtain one-dimensional materials having interesting physical properties (especially in terms of conductivity and magnetism), the Applicant has developed the synthesis and studied the properties of new polymers which comprise in their structure recurrence units. containing at least one silicon atom and at least two thiophene rings.

In the prior art, WP WEBER et al. [Polymer Bulletin, 21 (1989) 133] reported the synthesis of a polybis (silyl) thiophene polymer by polycondensation of 2,5-bis (chlorodimethylsilyl) thiophene with sodium in toluene.

<Tb>

<SEP> CH3 <SEP> CH3 <SEP> CH3 <SEP> CH3
<tb> CH3-SiSi-CH3 <SEP> Na <SEP>><SEP> - <SEP> If <SEP> S
<tb><SEP> l <SEP> l <SEP> Toluene / 100C <SEP> I <SEP> IF
<tb><SEP> C1 <SEP> C1 <SEP> CH3 <SEP> CH3 <SEP> n
<Tb>
This method can not, however, be used to synthesize a family of polymers having in their structure recurrence units containing at least one silicon atom and at least two thiophene rings.

 Continuing work in this field of the art since 1986, the Applicant has now found, and this is the first object of the present invention, a method that can synthesize the previously described family of polymers.

dans laquelle - les substituants R1 et R2, identiques ou différents, représentent chacun un radical alkyle linéaire ou ramifié ayant de 1 à 6 atomes de carbone; ou un radical phényle éventuellement substitué par un ou deux radicaux alkyles et/ou alkoxy ayant de 1 à 3 atomes de carbone, - le symbole m1 représente un nombre allant de 1 à 6
* avec un réactif (b) de formule:
Br - A - Br (Il) dans laquelle le symbole A représente un radical divalent de structure

dans laquelle le symbole m2 est un nombre allant de 1 à 3.More specifically, the present invention, in its first object, relates to a process for the preparation of polysilthiophenediyls which comprise in their structure recurrence units containing at least one silicon atom and at least two thiophene rings, characterized in that one carries out a polycondensation reaction by directly reacting a reagent (a) of formula

in which - the substituents R 1 and R 2, which are identical or different, each represent a linear or branched alkyl radical having from 1 to 6 carbon atoms; or a phenyl radical optionally substituted with one or two alkyl and / or alkoxy radicals having from 1 to 3 carbon atoms, the symbol m1 represents a number ranging from 1 to 6;
with a reagent (b) of formula:
Br - A - Br (II) in which the symbol A represents a divalent radical of structure

wherein the symbol m2 is a number from 1 to 3.

 According to a preferred embodiment, the process according to the present invention consists in reacting a reagent (a) of formula (I) with a reagent (b) of formula (II) in which A = A2.

The reagents (a) of formula (I) are obtained by applying the following synthesis scheme

<tb><SEP> 00C <SEP> / <SEP> 3H
<tb><SEP> + <SEP> + <SEP> n-BuLi <SEP>><SEP>><SEP> Li
<tb><SEP> S / <SEP> solvent <SEP> 3
<tb><SEP> iaprotic <SEP> 2
<tb><SEP> I
<tb><SEP> 0.5 <SEP> C <SEP> If <SEP> Cl
<tb><SEP> R2 <SEP> ~ <SEP> mi
<tb><SEP> Ri <SEP> Ri
<tb><SEP> 2 <SEP> R1
<tb><SEP> If <SEP> AT <SEP> i <SEP> If
<tb> Li-Y (<SEP> 3H <SEP> S <SEP> S
<tb><SEP> R2 <SEP> ml <SEP> solvent <SEP> R2 <SEP> ~ <SEP> mi
<tb><SEP> 4 <SEP> aprotic <SEP> 3
<tb><SEP> 2 <SEP> 2 <SEP> ZnCl2
<tb><SEP> 23 <SEP> C / 1H
<tb><SEP> solvent
<tb><sep> aprotic
<tb><SEP> Ri
<tb><SEP> C <Z><SEP> If <SEP> ZnCl <SEP> (I)
<tb><SEP> S <SEP>-ZnC'1<SEP> S
<tb><SEP> R2 <SEP> mi
<tb><SEP> 5
<Tb>
It should be noted that the reagent (a) of formula (I) encompasses undescribed species so far, so new; The precursor species with structure 4 are also new.

As regards reagent (b) of formula (II), it includes compounds which are known and some of which are commercially available such as paradibromobenzene and dibromothiophene; for the di-brominated compounds of bis and terthiophenes, reference can be made to A. MAC EACHERN et al.
Tetrahedron, 44 (1988) 2403.

 The polycondensation reaction is generally carried out in a homogeneous medium in the presence of an aprotic solvent or mixture of aprotic solvents common to the starting reagents (a) and (b). Preferred solvents are, for example, tetrahydrofuran, toluene, n-pentane and n-hexane. This reaction is still generally carried out under agitation and under an inert atmosphere at a temperature generally in the range of 40 to 70 ° C, using a number of moles of dibromo reagent (b) per mole of reagent (a). in the range from 1 to 4 and preferably from 1 to 3. The reaction is preferably carried out in the presence of a catalyst based for example on palladium or nickel taken in metallic form or in the form of A complex based on such a metal, a suitable catalyst is Pd [P (C 6 H 5) 314. The proportion of catalyst, when one is used, is in the range of 0.1 to 2. moles of catalyst per 100 moles of dibromo reagent (b).

 An advantageous procedure consists in directly introducing the reagent (a) onto the reagent (b), which is optionally mixed with the catalyst, with stirring, and then, once the reagent has been introduced, the stirring is maintained for 24 hours at the temperature chosen in FIG. range from 40 to 70 C.

 The reaction medium is then finally treated in order to recover the polymer that has been prepared. In this context, the reaction medium at room temperature is subjected to rapid hydrolysis using an aqueous solution of an alkaline or alkaline earth salt of hydracid so as to remove the inorganic salts present in the medium.

 In the case where all or part of the polymer has precipitated in the reaction medium, it is recovered by filtration and the polymer is dried under vacuum. In the case where the polymer is partially soluble or totally soluble, extraction of the organic phase is carried out with a suitable solvent, followed by drying and distillation of the solvents under reduced pressure.

libres les transforment en liaisons terminales

tandis que les liaisons terminales -A-Br ne sont pas altérées par ce traitement.By this treatment of the reaction medium, the hydrolysis of the terminal bonds

free transform them into terminal links

while terminal -A-Br bonds are not impaired by this treatment.

 The present invention also relates, and this is the second object of the present invention, the polysilthiophenediyls that are likely to be obtained by the method just described.

dans laquelle - R1 et R2 ont les significations générales indiquées ci-avant à propos de la formule (I) ; - le symbole ml représente un nombre entier allant de 1 à 6 ; - le symbole A a les significations générales indiquées ci-avant à propos de la formule (Il)
- le symbole n représente un nombre entier ou fractionnaire se situant dans l'intervalle allant de 2 à 1000.More specifically, these polysilthiophenediyls are characterized in that they essentially correspond to the following formula

wherein - R1 and R2 have the general meanings given above with respect to formula (I); the symbol ml represents an integer ranging from 1 to 6; - the symbol A has the general meanings indicated above concerning the formula (II)
the symbol n represents an integer or fractional number lying in the range from 2 to 1000.

 The polysilthiophenediyls obtained can be constituted by a single polymeric species or by a mixture of two or more polymer species which differ from each other essentially by the number n of the recurrence units.

As preferentially representative polysilthiophenediols, mention may be made of those which correspond to formula (III) in which the symbol
A = A2.

As specific examples of polysilthiophenediyls which are obtained by the process of the invention, mention may be made in particular
1. when: reagent (a) = compound of formula (I) with mi 1 reagent (b) = compound of formula (II) with A = A2 and m2 = 1

2. when: the reagent (a) = compound of formula (I) with mi 2 reagent (b) = compound of formula (II) with A = A2 er me = 1

3. when: reagent (a) = compound of formula (I) with m = 1 reagent (b) = compound of formula (II) A = A2 and m2 = 3

In their undoped state, the polysilthiophenediyls of formula (III) according to the first invention exhibit a conductivity of less than 10-8 ohm-1.cm-1, corresponding to a resistive state. It is known that organic polymers comprising a system accumulation Unsaturated carbon compounds are systems that can be doped (n-doping or p-doping), the coverage of orbitals being sufficient to ensure the delocalization of a negative or positive charge and consequently a metallic conductivity (Handbook of conducting polymers, TASKOTHEIM Editor, Marcel
Dekker Inc. Publ. New York, 1986). The polysilthiophenediyls according to the present invention can be used in such polymer-doping systems by using a doping agent such as, for example, FeCl 3 or NoBF 4 and pass to a conductive state (conductivity of about 10 -2 ohm-1 cm -1). 1).

 The following examples are given for illustrative purposes, but not limiting.

 In the examples which follow, all the reactions are carried out under an inert atmosphere by operating in a Schlenck tube connected to a vacuum ramp.

et un réactif de formule (b)

1. Préparation de

Example 1
In this example, the polycondensation is described between a reagent of formula (a)

and a reagent of formula (b)

1. Preparation of

 This reagent is prepared from dimethyldithienylsilane by treatment in aprotic solvent medium at 00C with two moles of n-butyllithium per mole of dithienylsilane. More precisely, n-butyllithium (0.030 mol) dissolved in 12 cm 3 of n-hexane is added at 00 ° C. to dimethyldithienylsilane (0.013 mol, 2.92 g) dissolved in 20 cm 3 of tetrahydrofuran. After three hours of reaction at 0 ° C, the solution is added to the zinc chloride (0.028 mole 3.81 g) in 20 cm3 of tetrahydrofuran at room temperature.

2. Polycondensation reaction
The previous solution after stirring for one hour at room temperature is added to the dibromothiophene (0.028 mol, 6.77 g) and the palladium catalyst Pd (PPh3) 4 (1 mol% dibromothiophene, 300 mg) in 20 cm3. of tetrahydrofuran. The whole is heated 24 hours at 50 ° C.

After returning to ambient temperature, the reaction mixture is subjected to rapid hydrolysis by adding all at once to 20 cm 3 of a saturated solution of NH 4 Cl in water.

 a) The portion of the polymer precipitated in the reaction medium is filtered on a beaker and dried under vacuum.

- des groupements terminaux X et Y où X = H et Y = Br
* qui présente les caractéristiques suivantes
Ww = 2230 g/mole,
Wn = 1695 g/mole, soit environ 6 unités de récurrence par
chai ne,
indice de polydispersité : I = Mw/Mn = 1,31
température de fusion : 170-174 C
b) Le polymère en solution dans la phase organique est extrait à l'éther éthylique (ou oxyde d'éthyle ; 3 fois 20 cm3). L'extrait global est ensuite séché sur MgS04 anhydre, puis les solvants sont éliminés sous pression réduite.Le polymère est alors repris dans 20 cm3 de tétrahydrofuranne et est précipité par addition dans 20 cm3 de méthanol.1.3 g of a polymer product having the appearance of an orange powder are collected in this way.
* which includes in its structure - formula recurrence units

terminal groups X and Y where X = H and Y = Br
* which has the following characteristics
Ww = 2230 g / mole,
Wn = 1695 g / mole, or about 6 recurrence units per
chai do,
polydispersity index: I = Mw / Mn = 1.31
melting temperature: 170-174 ° C
b) The polymer in solution in the organic phase is extracted with ethyl ether (or diethyl ether, 3 times 20 cm 3). The whole extract is then dried over anhydrous MgSO4 and the solvents are then removed under reduced pressure. The polymer is then taken up in 20 cm3 of tetrahydrofuran and is precipitated by addition in 20 cm3 of methanol.

1.3 g of a polymer product having the same appearance and the same structure as the preceding polymer are collected in this way.
Mw = 2220 g / mole
Mn = 1690 g / mole or about 6 recurrence units per
chai
polydispersity index: I = Mw / Mn = 1.31
melting temperature: 124-126 ° C.

 The products of the polycondensation reaction were identified, in this example as in those which follow, by spectroscopic studies (infra-red, ultraviolet and nuclear magnetic resonance proton, carbon 13 and silicon 29).

 Molecular weights were determined by size exclusion chromatography using a polystyrene calibration, solvent tetrahydrofuran.

et un réactif de formule (b)

1. Préparation de

Example 2
In this example, the polycondensation is described between a reagent of formula (a)

and a reagent of formula (b)

1. Preparation of

 This reagent is prepared in the same manner as in Example 1 from dimethyldithienylsilane (0.006 mol, 1.34 g).

2. Polycondensation reaction
The solution of the preceding reagent after stirring for one hour at ambient temperature is added to the dibromoterthiophene (0.006 mol 2.44 g) and the palladium catalyst Pd (PPh 3) 4 (1 mol% of dibromoterthiophene, 70 mg) in cm3 of tetrahydrofuran. The whole is heated for 24 hours at 50 ° C. During the reaction, the solution becomes nonhomogeneous After returning to ambient temperature, the reaction mixture is subjected to rapid hydrolysis by adding all at once to 10 cm.sup.3. saturated solution of NH4Cl in water.

 The part of the polymer precipitated in the reaction medium is filtered on a beaker and dried under vacuum.

-et des groupements terminaux X et Y où X = H et Y = Br
* qui présente les caractéristiques suivantes
Mw = 2350 g/mole,
Mn = 1890 g/mole, soit environ 4 unités de récurrence par
chai ne,
indice de polydispersité : I = Mw/Mn = 1,24
température de fusion : 260-290"C. 2.0 g of a polymeric product having the appearance of an orange powder are collected in this way.
* which includes in its structure - formula recurrence units

and terminal groups X and Y where X = H and Y = Br
* which has the following characteristics
Mw = 2350 g / mole,
Mn = 1890 g / mole, or about 4 recurrence units per
chai do,
polydispersity index: I = Mw / Mn = 1.24
melting temperature: 260-290 ° C.

et un réactif de formule (b)

1. Préparation de

Example 3
In this example, the polycondensation is described between a reagent of formula (a)

and a reagent of formula (b)

1. Preparation of

 This reagent is prepared by the action of n-butyllithium (0.025 mol) in solution in 10 cm3 of n-hexane on diphenyldithienylsilane (0.011 mol, 3.83 g) dissolved in 20 cm3 of tetrahydrofuran. After three hours of reaction at 0 ° C., the solution is added to the zinc chloride (0.024 mol, 3.26 g) in 20 cm3 of tetrahydrofuran at room temperature.

2. Polycondensation reaction
The previous solution after stirring for one hour at room temperature is added to the dibromothiophene (0.022 mol, 5.32 g) and the palladium catalyst Pd (PPh3) 4 (1 mol% dibromothiophene, 240 mg) in 20 cm3. of tetrahydrofuran. The whole is heated 24 hours at 50 C.

The solution remains homogeneous. After returning to ambient temperature, the reaction mixture is subjected to rapid hydrolysis by adding all at once to 20 cm 3 of a saturated solution of NH 4 Cl in water. The organic phase is extracted three times with ethyl ether (20 cm3). The overall extract obtained is dried over anhydrous MgSO4 and the solvents are removed under reduced pressure. The polymer thus obtained is purified by chromatography on a toluene eluting florisil support.

- des groupements terminaux X et Y où X = H et Y = Br
* qui présente les caractéristiques suivantes
Mw = 2510 g/mole,
Mn = 1640 g/mole, soit environ 4 unités de récurrence par
chai ne,
indice de polydispersité : I = Mw/Mn = 1,53. In this way, 3.3 g of a polymeric product having the appearance of an orange gum are collected in this way.
* which includes in its structure - formula recurrence units

terminal groups X and Y where X = H and Y = Br
* which has the following characteristics
Mw = 2510 g / mole,
Mn = 1640 g / mole, or about 4 recurrence units per
chai do,
polydispersity index: I = Mw / Mn = 1.53.

Claims (8)

 Process for the preparation of polysilthiophenediyls which comprise in their structure recurrence units containing at least one silicon atom and at least two thiophene rings, characterized in that a polycondensation reaction is carried out by reacting directly  * nn reagent (a) of formula

 in which - the substituents R 1 and R 2, which are identical or different, each represent a linear or branched alkyl radical having from 1 to 6 carbon atoms; or a phenyl radical optionally substituted with one or two alkyl and / or alkoxy radicals having from 1 to 3 carbon atoms, the symbol ml represents a number ranging from 1 to 6;  * with a reagent (b) of formula  Br - A - Br (11) in which the symbol A represents a divalent radical of structure

 wherein the symbol m2 is a number from 1 to 3.  2. Process according to claim 1, characterized in that it consists in reacting a reagent (a) of formula (I) with a reagent (b) of formula (II) in which A = A2.  3. Method according to any one of claims 1 and 2 above, characterized in that the polycondensation reaction is conducted in a homogeneous medium in the presence of an aprotic solvent or mixture of aprotic solvents common (s) reagents (a) and (b) by stirring and under an inert atmosphere at a temperature in the range of 40 to 70 ° C and using a number of moles of dibromo reagent (b) per mole of reagent (a) falling within the interval from 1 to 4.  4. Process according to any one of the preceding claims 1 to 3, characterized in that the polycondensation reaction is carried out in the presence of a catalyst based on palladium or nickel taken in metallic form or in the form of a complex based on such a metal with a catalyst proportion ranging from 0.1 to 2 moles per 100 moles of dibromo reagent (b).  5. As novel industrial products, the polysilthiophenediyls which can be obtained by the process according to any one of the preceding claims 1 to 4, characterized in that they essentially correspond to the following formula:

 wherein: - the symbols R1, R2, ml and A have the general meanings indicated above in claim 1; the symbol n represents an integer or fractional number lying in the range from 2 to 1000.  Polysilthiophenediyl compounds according to claim 5, characterized in that they correspond to formula (III) in which the symbol A = A2, with A2 having the meaning given above in claim 1.  7. As new industrial products especially intended for carrying out the process according to any one of the preceding claims 1 to 4, the species of formula

 wherein the symbols R1, R2 and ml have the general meanings given above in claim 1.  8. As new industrial products especially intended for carrying out the process according to any one of the preceding claims 1 to 4, the species of formula

 wherein the symbols R1, R2 and ml have the general meanings given above in claim 1.