SILYLATED OLIGOGERMANES AND POLYCYCLIC SILICON-GERMANIUM COMPOUNDS, PROCESSES FOR THEIR PREPARATION AND THEIR USE FOR THE PREPARATION OF A SI- AND GE-CONTAINING SOLID

The present invention relates to a compound of the formula (Ia) or the formula (Ib)   a process for their preparation; and the use of the compound for the preparation of the Si- and Ge-containing solid.

FIELD OF THE INVENTION

The present invention relates to silylated oligogermanes and polycyclic silicon-germanium compounds, a process for their preparation and their use for the preparation of a Si- and Ge-containing solid.

BACKGROUND OF THE INVENTION

Triphenylgermylsilane and its preparation is described in EP 3 409 645 A1.

Chlorosilylarylgermanes and their preparation are disclosed in EP 3 410 466.

Ritter et al. J. Am. Chem. Soc. 2005, 127, 9855 describes the use of (H3Ge)xSiH4-xfor the preparation of semiconductor nanostructures on silicon.

Starting from the prior art, it is desirable to prepare improved silicon-germanium compounds, in particular storage-capable silicon-germanium compounds, and to provide a flexible process for the simple preparation of a large number of such compounds. It is also desirable to provide compounds which can be used to produce Si/Ge solids.

The object of the present invention is to overcome disadvantages of the prior art, in particular to prepare storage-capable, tailored silicon-germanium compounds which are suitable for the preparation of Si/Ge solids.

OVERVIEW OF THE INVENTION

This object is achieved by a compound of the formula (Ia) or (Ib)

in which formula (Ia)n is an integer from 1 to 10;R1and R2are independently of each other selected from the group consisting of C1to C20alkyl, C2to C20alkenyl, C2to C20alkynyl, C3to C20cycloalkyl, C6to C20aryl, C7to C20arylalkyl and C7to C20alkylaryl; andX1is selected from the group consisting of H, SiH3, halogen and Si(Y1)3with Y1=halogen;

in which formula (Ib)E1to E6are independently of each other Si or Ge;X11to X14are independently of each other selected from the group consisting of H, SiH3, halogen and Si(Y2)3;Y2is independently selected from C1to C20alkyl and halogen;R3to R14are independently of each other selected from the group consisting of C1to C20alkyl, C2to C20alkenyl, C2to C20alkynyl, C3to C20cycloalkyl, C6to C20aryl, C7to C20arylalkyl, C7to C20alkylaryl and Z; andZ is independently selected from the group consisting of H, halogen and C1to C20alkyl.

A Compound of the Formula (Ia)

It may be provided that n is an integer from 1 to 8. It may further be provided that n is an integer from 1 to 6. It may further be provided that n is an integer from 1 to 4. It may also be provided that n is an integer from 2 to 10. It may also be provided that n is an integer from 2 to 8. It may also be provided that n is an integer from 2 to 6. It may also be provided that n is an integer from 2 to 5. Finally, it may be provided that n is an integer from 2 to 4.

It may be provided that R1and R2are independently of each other selected from the group consisting of C1to C12alkyl, C2to C12alkenyl, C2to C12alkynyl, C3to C12cycloalkyl, C6to C12aryl, C7to C13arylalkyl and C7to C13alkylaryl.

It may be provided that R1and R2are independently of each other selected from the group consisting of C1to C12alkyl, C6to C12aryl, C7to C13arylalkyl and C7to C13alkylaryl.

It may be provided that R1and R2are independently of each other selected from the group consisting of C1to C20alkyl and C6to C20aryl.

It may be provided that R1and R2are independently of each other selected from the group consisting of C1to C12alkyl and C6to C12aryl.

It may be provided that R1and R2are independently of each other phenyl or methyl.

It may be provided that R1and R2are the same. In this context, it may be provided that all R1and R2contained in the compound of the formula (Ia) are the same and are selected from one of the groups mentioned above.

It may be provided that X1is selected from the group consisting of H, SiH3, Cl and SiCl3.

A Compound of the Formula (Ib)

It may be provided that at least three of E1to E6are Ge and the remaining of E1to E6are Si. It may be provided that four, five or six of E1to E6are Ge and the remaining of E1to E6are Si. It may be provided that four or five of E1to E6are Ge and the remaining of E1to E6are Si.

It may be provided that R3to R14are independently of each other selected from the group consisting of C1to C12alkyl, C2to C12alkenyl, C2to C12alkynyl, C3to C12cycloalkyl, C6to C12aryl, C7to C13arylalkyl, C7to C13alkylaryl and halogen.

It may be provided that R3to R14are independently of each other selected from the group consisting of C1to C12alkyl, C6to C12aryl, C7to C13arylalkyl, C7to C13alkylaryl and halogen.

It may be provided that R3to R14are independently of each other selected from the group consisting of C1to C20alkyl, C6to C20aryl and halogen.

It may be provided that R3to R14are independently of each other selected from the group consisting of C1to C12alkyl and halogen.

It may be provided that R3to R14are independently of each other Cl or methyl.

It may be provided that two Rndirectly connected to the same Em(i.e., the two R in the pairs R3and R4, R5and R6, R7and R8, R9and R10, R11and R12, and R13and R14) are the same.

It may be provided that in the case that the Em(i.e., one of E1to E6) is Ge, the two Rndirectly connected to the Emare C1to C20alkyl. It may be provided that in the case that the Em(i.e., one of E1to E6) is Ge, the two Rndirectly connected to the Emare C1to C12alkyl. It may be provided that in the case that the Em(i.e., one of E1to E6) is Ge, the two Rndirectly connected to the Emare C1to C8alkyl. It may be provided that in the case that the Em(i.e., one of E1to E6) is Ge, the two Rndirectly connected to the Emare C1to C4alkyl. It may be provided that in the case that the Em(i.e., one of E1to E6) is Ge, the two Rndirectly connected to the Emare methyl.

It may be provided that in the case that the Em(i.e., one of E1to E6) is Si, the two Rndirectly connected to the Emare halogen. It may be provided that in the case that the Em(i.e., one of E1to E6) is Si, the two Rndirectly connected to the Emare Cl.

It may be provided that X11to X14are independently selected from the group consisting of H, SiH3, Si(C1to C20alkyl)3, Cl and SiCl3. It may be provided that X11to X14are independently of each other selected from the group consisting of H, SiH3, Si(C1to C12alkyl)3, Cl and SiCl3. It may be provided that X11to X14are independently of each other selected from the group consisting of H, SiH3, Si(C1to C8alkyl)3, Cl and SiCl3. It may be provided that X11to X14are independently of each other selected from the group consisting of H, SiH3, Si(C1to C4alkyl)3, Cl and SiCl3. It may be provided that X11to X14are independently of each other selected from the group consisting of Si(C1to C4alkyl)3and SiCl3.

It may be provided that the compound of the formula (Ib) is selected from one of the following compounds C1 to C4.

Process for Preparing a Compound of the Formula (Ia)

The object is further achieved by a process for preparing a compound of the formula (Ia) according to one of the preceding claims comprising reacting a compound of the formula (IIa)

with a compound of the formula (IIIa)

wherein X3to X10are independently halogen; and R1and R2are as defined above; and hydrogenating the product obtained by reacting the compound of the formula (IIa) with the compound of the formula (IIIa).

The ratio of compound (IIa) to compound (IIIa) can be from 10:1 to 1:20; 5:1 to 1:1; 2:1 to 1:10; 1.5:1 to 1:8; 1.2:1 to 1:5; 1:1 to 1:4.

It can be provided that the reaction of the compound of the formula (IIa) with the compound of the formula (IIIa) is carried out in the presence of a catalyst. It can be provided to use the catalyst in amounts of from 0.001 to 1 eq., preferably from 0.01 to 0.1 eq. It can be provided that the catalyst is a base. It can be provided that the catalyst is a base containing phosphorus or nitrogen. It can be provided that the catalyst is a base containing nitrogen. It can be provided that the catalyst is a phosphonium or ammonium salt. It can be provided that the catalyst is selected from [(R′)4P]Cl or [(R′)4N]Cl, wherein the radicals R′ are independently of each other selected from C1to C12alkyl, C6to C12aryl, C7to C13arylalkyl and C7to C13alkylaryl. It can be provided that the catalyst is [(R′)4N]Cl, wherein R′ is selected from methyl, ethyl, isopropyl, n-butyl and phenyl. It can be provided that the catalyst is [(R′)4N]Cl, wherein R′ is selected n-butyl.

It can be provided that the reaction of the compound of the formula (IIa) with the compound of the formula (IIIa) is carried out in a solvent. In the process, at least 5 mol of solvent can be used per mol of compound (IIIa), alternatively from 10 mol to 100 mol of solvent per mol of compound (IIIa). It can be provided that the solvent is an organic solvent. It can be provided that the solvent (both in the reaction step and in the hydrogenation step) is a non-polar organic solvent. It can be provided that the solvent is selected from n-pentane, n-hexane, n-heptane, cyclohexane, toluene, diethyl ether, dichloromethane, chloroform, tert-butyl methyl ether, acetone and tetrahydrofuran. It can be provided that the solvent is dichloromethane.

It can be provided that the reaction of the compound of the formula (IIa) with the compound of the formula (IIIa) is carried out at a temperature in a range from 0° C. to 50° C., 10° C. to 40° C., 15° C. to 30° C., 20° C. to 25° C., or 22° C. (=room temperature).

It can be provided that the reaction of the compound of the formula (IIa) with the compound of the formula (IIIa) is carried out for 5 min to 24 h, 30 min to 12 h, or 1 h to 4 h.

It can be provided that the hydrogenation of the product obtained by reacting the compound of the formula (IIa) with the compound of the formula (IIIa) is carried out by adding a hydrogenating agent. It can be provided that the hydrogenating agent is lithium aluminum hydride.

Process for Preparing a Compound of the Formula (Ib)

The object is further achieved by a process for preparing a compound of the formula (Ib) according to one of the preceding claims comprising reacting a compound of the formula (IIb)

with a compound of the formula (IIIb)

wherein Hal1to Hal8are independently halogen; and R3and R4are as defined above; andcrystallizing the product of the reaction of the compounds (IIb) and (IIIb).

It may be provided that in the process E1=Ge and E2and E3are each Si.

The molar ratio of compound (IIb) to compound (IIIb) can be from 10:1 to 1:40; 5:1 to 1:2; 2:1 to 1:20; 1.5:1 to 1:10; 1.2:1 to 1:8; 1:3 to 1:5, about 1:4.

It can be provided that the reaction of the compound of the formula (IIb) with the compound of the formula (IIIb) is carried out in the presence of a catalyst. It can be provided to use the catalyst in amounts of from 0.001 to 1 eq., preferably from 0.01 to 0.1 eq. It can be provided that the catalyst is a base. It can be provided that the catalyst is a base containing phosphorus or nitrogen. It can be provided that the catalyst is a base containing nitrogen. It can be provided that the catalyst is a phosphonium or ammonium salt. It can be provided that the catalyst is selected from [(R3)4P]Cl or [(R3)4N]Cl, wherein the radicals R3are independently of each other selected from C1to C12alkyl, C6to C12aryl, C7to C13arylalkyl and C7to C13alkylaryl. It can be provided that the catalyst is [(R3)4N]Cl, wherein R3is selected from methyl, ethyl, isopropyl, n-butyl and phenyl. It can be provided that the catalyst is [(R3)4N]Cl, wherein R3is selected n-butyl.

It can be provided that the reaction of the compound of the formula (IIb) with the compound of the formula (IIIb) is carried out in a solvent. In the process, at least 5 mol of solvent can be used per mol of compound (IIIb), alternatively from 10 mol to 100 mol of solvent per mol of compound (IIIb). It can be provided that the solvent is an organic solvent. It can be provided that the solvent (both in the reaction step and in the hydrogenation step) is a non-polar organic solvent. It can be provided that the solvent is selected from n-pentane, n-hexane, n-heptane, cyclohexane, toluene, diethyl ether, dichloromethane, chloroform, tert-butyl methyl ether, acetone and tetrahydrofuran. It can be provided that the solvent is dichloromethane.

It can be provided that the reaction of the compound of the formula (IIb) with the compound of the formula (IIIb) is carried out at a temperature in a range from 0° C. to 50° C., 10° C. to 40° C., 15° C. to 30° C., 20° C. to 25° C., or 22° C. (=room temperature).

It can be provided that the reaction of the compound of the formula (IIb) with the compound of the formula (IIIb) is carried out for 5 min to 24 h, 30 min to 12 h, or 1 h to 4 h.

It can be provided that the process further comprises reacting the product obtained after the crystallization with a Grignard reagent. A Grignard reagent is a compound of the general formula R—Mg-Hal with R=acyl (for example aryl or alkyl) and Hal=halogen (for example Cl or Br). Such a compound can be prepared by reacting acyl halide with magnesium in a suitable organic solvent. Suitable organic solvents are those which can form a coordinate bond to the Mg in the R—Mg-Hal by a free electron pair. An ether (preferably a dialkyl ether such as diethyl ether or a cyclic ether such as tetrahydrofuran (THF)) is preferably used as organic solvent. Grignard reagents and their preparation and use are well known from the prior art, in particular relevant textbooks of organic chemistry.

It can be provided that a compound of the formula (Ib) with X11to X14═Si(acyl)3is obtained by reacting a compound of the formula (Ib) with X11to X14=SiHal3with a Grignard reagent of the formula R—Mg-Hal with R=acyl in THF or diethyl ether. It can be provided that a compound of the formula (Ib) with X11to X14═Si(alkyl)3is obtained by reacting a compound of the formula (Ib) with X11to X14=SiHal3with a Grignard reagent of the formula R—Mg-Hal with R=alkyl in THF or diethyl ether. It can be provided that a compound of the formula (Ib) with X11to X14═Si(C1to C4alkyl)3is obtained by reacting a compound of the formula (Ib) with X11to X14=SiHal3with a Grignard reagent of the formula R—Mg-Hal with R═C1to C4alkyl in diethyl ether. It can be provided that a compound of the formula (Ib) with X11to X14═SiMe3is obtained by reacting a compound of the formula (Ib) with X11to X14═SiCl3with a Grignard reagent of the formula R—Mg-Hal with R=methyl in diethyl ether.

Preparation of a Si- and Ge-Containing Solid

The object is also achieved by the use of a compound according to the formula (Ia) or the formula (Ib) described above for preparing a Si- and Ge-containing solid.

It may be provided that the Si- and Ge-containing solid is an intermetallic phase, wherein the two semimetals Si and Ge are to be regarded as metals in this context. An intermetallic phase (also intermetallic compound) is a chemical compound of two or more metals. In contrast to alloys, the intermetallic phase has lattice structures which differ from those of the constituent metals. The lattice bond of the different atom types is a mixed form of a predominantly metallic bond and smaller proportions of other types of bonds (covalent bond, ion bond), whereby these phases have particular physical and mechanical properties.

It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 300° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 400° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 450° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 500° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 550° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 600° C. or more. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 400° C. to 1000° C. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 400° C. to 800° C. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 450° C. to 750° C. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 500° C. to 700° C. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of 550° C. to 650° C. It may be provided that the preparation of the Si- and Ge-containing solid comprises heating the compound to a temperature of about 600° C.

It may be provided that the preparation of the Si- and Ge-containing solid comprises depositing SiGe. It may be provided that the preparation of the Si- and Ge-containing solid comprises simultaneously depositing Si and Ge. It may be provided that the stoichiometric ratio of Si to Ge in the Si- and Ge-containing solid corresponds to the stoichiometric ratio of Si to Ge in the compound of the formula (Ia) or the formula (Ib). It may be provided that the stoichiometric ratio of Si to Ge in the Si- and Ge-containing solid corresponds to the stoichiometric ratio of Si to Ge in the compound of the formula (Ia) or the formula (Ib) with a deviation of 10%.

It may be provided that further elements contained in the Si- and Ge-containing solid are selected from the group consisting of carbon, oxygen, aluminum and mixtures thereof.

It may be provided that the heating of the compound of the formula (Ia) or of the formula (Ib)

during the preparation of the Si- and Ge-containing solid is accompanied by the formation of R1—H and R2—H, or R3—H and R4—H.

The term “alkenyl” as used herein refers to the mono-radical of a saturated chain or branched hydrocarbon having at least one double bond.

The term “alkynyl” as used herein refers to the mono-radical of a saturated chain or branched hydrocarbon having at least one triple bond.

The term “aryl” as used herein refers to the mono-radical of an aromatic cyclic hydrocarbon. Preferably, the aryl group contains 5 to 14 (e.g. 5, 6, 7, 8, 9, 10) carbon atoms, which may be arranged in one ring (e.g. “phenyl”=“Ph”) or in two or more fused rings (e.g. “naphthyl”). Exemplary aryl groups are, for example, cyclopentadienyl, phenyl, indenyl, naphthyl, azulenyl, fluorenyl, anthryl, and phenanthryl.

The term “cycloalkyl” as used herein refers to the cyclic, non-aromatic form of an alkyl.

The term “arylalkyl” as used herein refers to an aryl group substituted with at least one alkyl, e.g. tolueneyl.

The term “alkylaryl” as used herein refers to an alkyl group substituted with at least one aryl, e.g. 2-phenylethyl.

The term “halogen” as used herein refers to fluorine, chlorine, bromine, or iodine.

The present invention relates to the novel silylated oligogermanes of the formula (Ia)

The present invention also relates to the novel polycyclic silicon-germanium compounds of the formula (Ib)

Compounds of the formula (Ia) are obtainable via a novel synthesis, for example starting from diorganyldichlorogermane and hexachlorodisilane. The target compounds (Ia) can be prepared, for example, by adding tetrabutylammonium chloride and subsequent hydration with lithium aluminum hydride. These oligogermanes are distinguished by their thermolysis behavior, for example, in the deposition of pure Si and Ge, the residue obtained here consisting of pure Si and Ge in the stoichiometric ratio.

Compounds of the formula (Ib) are obtainable via a novel synthesis, for example starting from diorganyldichlorogermane and hexachlorodisilane. The target compounds (Ib) can be prepared, for example, by adding tetrabutylammonium chloride and optionally subsequent reaction with a Grignard reagent. These polycyclic silicon-germanium compounds are distinguished by their thermolysis behavior, for example, in the deposition of pure Si and Ge, the residue obtained here consisting of pure Si and Ge in the stoichiometric ratio.

General Synthesis Route for the Compounds of the Formula (Ia)

The reaction of diorganodichlorogermanes with hexachlorodisilane with addition of tetrabutylammonium chloride followed by hydrogenation with LialH4 leads to the selective formation of the silylated oligogermanes H3Si—(GeR2)n—X1(where n=1-4; R=alkyl, aryl; X1═H, Cl, SiH3, SiCl3).

Particularly preferred compounds which can be prepared in this way are the following compounds A1 to A8

The compounds according to the invention can be prepared according to the following Scheme 1.

Scheme 1 shows the reaction of diorganodichlorogermanes with hexachlorodisilane with addition of tetrabutylammonium chloride to give the trichlorosilylated oligogermanes Cl3Si—(GeR2)n—Y (B, where n=1-4; R=alkyl, aryl; Y═Cl, SiCl3). The subsequent hydrogenation with LiAlH4 leads to the selective formation of the silylated oligogermanes H3Si—(GeR2)n—Y (A, m it n=1-4; R=alkyl, aryl; Y═H, Cl, SiH3, SiCl3).

Synthesis Examples for the Compounds of the Formula (Ia)

Synthesis of Cl3Si-Ph2Ge—SiCl3(B1)

A solution of [nBu4N]Cl (90 mg, 0.34 mmol, 0.2 eq.), Ph2GeCl2(500 mg, 1.70 mmol, 1 eq.), 5 ml of CH2Cl2and Si2Cl6(1800 mg, 6.80 mmol, 4 eq.) was stirred at room temperature overnight and then freed from all volatile constituents under reduced pressure. The orange-colored viscous residue was extracted with 6 ml of n-hexane and all volatile constituents were removed from the filtrate under reduced pressure. In this way, Cl3Si-Ph2Ge—SiCl3(79%, 659 mg, 1.34 mmol) was obtained as a colorless, viscous liquid.

Synthesis of Cl3Si-Me2Ge—SiCl3(B2)

Cl3Si-Me2Ge—SiCl3was identified using the following signals:

Synthesis of Cl3Si-Ph2Ge-Ph2Ge—SiCl3(B3)

Synthesis of Cl3Si-Me2Ge-Me2Ge—SiCl3(B4)

Cl3Si-Ph2Ge-Ph2Ge—Cl was identified using the following signals:

The product from the synthesis of H3Si-Ph2Ge—SiH3was stored at room temperature for 6 months. The subsequent investigation by means of NMR spectroscopy and GC/MS confirmed the formation of H3Si-Ph2Ge—H.

H3Si-Ph2Ge—H was identified using the following signals:

Synthesis of H3Si-Ph2Ge—SiH3(A2)

Cl3Si-Ph2Ge—SiCl3(400 mg, 0.807 mmol, 1 eq.) was dissolved in 10 ml of Et2O and LiAlH4(93 mg, 2.42 mmol, 3 eq.) was added in portions. The solution remained clear and colorless and a gray solid precipitated. After stirring for 30 minutes, all volatile constituents were removed under reduced pressure and the residue was stirred with 8 ml of n-hexane for 16 hours. Filtration of the n-hexane solution and liberation of the extract from all volatile constituents under reduced pressure yielded H3Si-Ph2Ge—SiH3(55%, 128 mg, 0.443 mmol) as a viscous, colorless liquid. The product was identified by means of NMR spectroscopy and GC/MS.

Synthesis of H3Si-Me2Ge—SiH3(A3) and H3Si-Me2Ge-Me2Ge—SiH3(A5)

50 mg of a mixture of Cl3Si-Me2Ge—SiCl3(B2) and Cl3Si-Me2Ge-Me2Ge—SiCl3(B4) was dissolved in 0.8 ml of Et2O in an NMR tube and an excess of LiAlH4(15 mg, 0.4 mmol, about 3 eq.) was slowly added. 0.2 ml of the solution was taken for a GC/MS sample and diluted with a further 0.5 ml of Et2O. The remaining reaction solution was melted in the NMR tube under vacuum and measured by NMR spectroscopy. GC/MS and NMR spectroscopy confirmed the formation of H3Si-Me2Ge—SiH3and H3Si-Me2Ge-Me2Ge—SiH3.

Synthesis of H3Si-Ph2Ge-Ph2Ge—SiH3(A4)

Cl3Si-Ph2Ge-Ph2Ge—SiCl3(200 mg, 0.280 mmol, 1 eq.) was dissolved in 6 ml of Et2O and LiAlH4(37 mg, 0.98 mmol, 3.5 eq.) was added in portions. The solution remained clear and colorless and a gray solid precipitated. After stirring for 30 minutes, all volatile constituents were removed under reduced pressure and the residue was stirred with 8 ml of n-hexane for 16 hours. Filtration of the n-hexane solution and liberation of the extract from all volatile constituents under reduced pressure yielded H3Si-Ph2Ge-Ph2Ge—SiH3(55%, 128 mg, 0.44 mmol) as a colorless, crystalline solid. The product was identified by means of NMR spectroscopy.

Synthesis of H3Si-Ph2Ge—SiCl3(A6)

NMR signals of H3Si-Ph2Ge—SiCl3:

Synthesis of H3Si-Ph2Ge-Ph2Ge—SiCl3(A7)

Cl3Si-Ph2Ge-Ph2Ge—SiCl3(200 mg, 0.280 mmol, 1 eq.) in 2 ml of Et2O was initially charged and LiAlH4(10 mg, 0.28 mmol, 1 eq.) was slowly added. The solution remained colorless and a gray solid precipitated. The solid was filtered off and the filtrate was freed from the solvent under ambient pressure. The residue was extracted with 4 ml of n-hexane and then all volatile constituents of the extract were removed under ambient pressure.13C and29Si NMR spectroscopy of the solid obtained confirmed the presence of the starting material Cl3Si-Ph2Ge-Ph2Ge—SiCl3, H3Si-Ph2Ge-Ph2Ge—SiCl3and H3Si-Ph2Ge-Ph2Ge—SiH3. It was also possible to obtain the crystal structure of H3Si-Ph2Ge-Ph2Ge—SiCl3by means of X-ray diffractometry.

NMR signals of H3Si-Ph2Ge-Ph2Ge—SiCl3:

Synthesis of H3Si—(Ph2Ge)4—SiH3(A8)

An NMR tube was filled with [nBu4N]Cl (10 mg, 0.03 mmol, 0.2 eq.), Ph2GeCl2(50 mg, 0.17 mmol, 1 eq.), 0.5 ml of CD2Cl2and Si2Cl6(90 mg, 0.34 mmol, 2 eq.).13C and29Si NMR spectroscopy of the clear, colorless solution confirmed the presence of Cl3Si-Ph2Ge-Ph2Ge—SiCl3, Cl3Si-Ph2Ge—SiCl3and SiCl4. The NMR tube was opened and all volatile constituents were removed under ambient pressure. The residue was dissolved in a new NMR tube in 0.5 ml of Et2O and LiAlH4(7 mg, 0.17 mmol, 1 eq.) was added. A colorless solution with a gray sediment and a fine, colorless solid was then present.13C and29Si NMR spectroscopy of the reaction solution gave the signals of several unknown species which could not be characterized more precisely. After opening the NMR tube and removing the volatile constituents under ambient pressure, a crystal was obtained which was identified by means of X-ray diffractometry as the tetragerman H3Si—(Ph2Ge)4—SiH3.

Synthesis Examples for the Compounds of the Formula (Ib)

Synthesis of C10H30Cl4Ge5Si9(C1)

Synthesis of C8H24Cl16Ge4Si10(C2)

Synthesis of C22H66Cl2Ge5Si9(C3)

C1 (12 mg, 0.009 mmol, 1 eq.) and 0.5 ml of Et2O were filled into an NMR tube and an Et2O solution of MeMgBr (3 M, 0.1 ml, 0.30 mmol, 30 eq.) was added with ice cooling. The NMR tube was melted in under vacuum. After about two weeks at room temperature, a complete conversion could be observed by means of NMR spectroscopy. The NMR tube was then opened, the contents were transferred together with 3 ml of Et2O into a Schlenk flask and then 0.05 ml of MeOH was added with ice cooling. After stirring for 10 minutes, all volatile constituents were removed, and the residue was extracted with a total of 7 ml of n-hexane. Again, all volatile constituents were removed from the extract, whereupon C3 (82%, 8 mg, 0.008 mmol) was obtained as a colorless crystalline solid. The product was characterized by means of X-ray diffractometry (orthorhombic, Cmcm) and NMR spectroscopy.

Synthesis of C20H60Cl4Ge4Si10(C4)

C2 (20 mg, 0.015 mmol, 1 eq.) and 0.5 ml of Et2O were filled into an NMR tube and an Et2O solution of MeMgBr (3 M, 0.2 ml, 0.60 mmol, 40 eq.) was added with ice cooling. The NMR tube was melted in under vacuum. After heating for 14 h at 60° C., a complete conversion could be observed by means of NMR spectroscopy. The further purification was then carried out analogously to C3.

Finally, C4 (89%, 16 mg, 0.016 mmol) was obtained as a colorless crystalline solid. The product was characterized by means of X-ray diffractometry (orthorhombic, Pbca) and NMR spectroscopy.

Preparation of Si- and Ge-Containing Solids

Si- and Ge-Containing Solids can be prepared starting from the compounds according to the invention, for example according to the following reaction scheme.

Deposition of SiGe at 600° C.

H3Si-Ph2Ge-Ph2Ge—SiH3(13 mg, 0.025 mmol) was weighed into a crucible and a thermogravimetric analysis (TGA) was carried out. For this purpose, the mixture was heated to 600° C. under an argon atmosphere at a rate of 10 K/min, this temperature was maintained for 5 minutes and the sample was then cooled again to room temperature at the same rate. The residue obtained, a brownish powder, was examined by means of EDX. For this purpose, some of the sample was applied to a support and coated with gold for better measurement accuracy. In addition to silicon and germanium, the subsequent measurement showed only gold, as well as small amounts of carbon, oxygen and aluminum. The evaluation of the data of two analyzed regions showed a silicon-germanium ratio of 1.0:1.0 or 1.0:1.1.

The features of the invention disclosed in the above description and in the claims can be essential both individually and in any combination for the realization of the invention in its various embodiments.