A. V. Lis

Properties of aminosilane precursors for the preparation of Si-C-N films

RnSi(NEt2)4 − n aminosilanes have been synthesized by reacting the RnSiCI4 − n (R = H, CH3; n = 1, 2) organylchlorosilanes with diethylamine. Using IR, UV, and NMR (1H, 13C, and 29Si) spectroscopies and elemental analysis, we have identified the reaction products and determined their spectroscopic characteristics. Vapor pressure measurements have been used to determine the saturated vapor pressure as a function of temperature and calculate the thermodynamic characteristics of vaporization. Thermodynamic modeling of chemical vapor deposition processes has been performed with the aim of predicting the phase composition of the deposit as a function of the nature of the precursor and process conditions.

Films based on the phases in the Si-C-N System: Part 1. Synthesis and characterization of bis(trimethylsilyl)ethylamine as a precursor

The characterization of bis(trimethylsilyl)ethylamine was carried out using a combination of IR, UV, 1H, 13C, 29Si, and 15N NMR spectroscopy, as well as elemental analysis. The spectral characteristics of the compound were determined. The temperature dependence of the saturated vapor pressure was established by tensimetric studies, and the thermodynamic characteristics of vaporization were calculated. Thermodynamic simulation of the chemical vapor deposition was performed and was used as a basis for predicting the composition of the deposited phase complexes depending on the type of reagent and the process conditions.

Migration of trimethylsilyl group in the reaction of sodium bis(trimethylsilyl)amide with bromobenzene

The reaction of sodium bis(trimethylsilyl)amide with bromobenzene gave a mixture of N,N-bis-(trimethylsilyl)aniline and N,2-bis(trimethylsilyl)aniline, the latter being a rearrangement product formed via 1,3-migration of trimethylsilyl group from the nitrogen atom to the ortho-carbon atom in the benzene ring.

Et3GeN(SiMe3)2 and Et3SnN(SiMe3)2: New precursors for chemical vapor deposition processes

We have synthesized the germanium- and tin-containing organosilicon compounds Et3GeN(SiMe3)2 and Et3SnN(SiMe3)2 as new precursors for the preparation of materials by chemical vapor deposition. The compounds were characterized by NMR, IR and UV spectroscopies and thermal analysis. Using vapor pressure measurements, we obtained temperature dependences of their saturated vapor pressure. We assessed their thermal stability and calculated the thermodynamic characteristics of vaporization of the organosilicon compounds.

Reaction of sodium bis(trimethylsilyl)amide with bromotoluenes

Isomeric bromotoluenes react with sodium bis(trimethylsilyl)amide through intermediate methylbenzynes, yielding N,N-bis(trimethylsilyl)toluidines and rearrangement products, N,2-bis(trimethylsilyl)toluidines. The formation of the latter is a rare example of 1,3-migration of silyl group from nitrogen atom to aromatic carbon atom. The rearrangement is favored by increased solvent polarity and elevated temperature. The observed product ratio can be rationalized by DFT quantum chemical calculations.

Reaction of iodo(trimethyl)silane with N,N-dimethyl carboxylic acid amides

The reactions of iodo(trimethyl)silane with N,N-dimethylformamide and N,N-dimethylacetamide Me2NCOR (R = H, Me) at a molar ratio of 1: 2 involved mainly cleavage of the N-C(=O) bond with formation of up to 80% of N,N-dimethyltrimethylsilylamine Me3SiNMe2 and the corresponding acyl iodide RCOI. In the reaction with N,N-dimethylformamide, formyl iodide HCOI was detected for the first time by gas chromatography-mass spectrometry. The contribution of Me-N bond cleavage, leading to N-methyl-N-trimethylsilyl derivative Me(Me3Si)NCOR and methyl iodide was considerably smaller. Another by-product was the corresponding N-methyl imide MeN(COR)2 formed by reaction of the initial amide with acyl iodide. The primary intermediate in the reaction of iodo(trimethyl)silane with DMF and DMA is quaternary ammonium salt [Me2(Me3Si)N+COR] I− which decomposes via dissociation of the N-CO and N-Me bonds.

Peculiarities of the reaction of alkali metal bis(trimethylsilyl)amides with halobenzenes

Lithium and sodium bis(trimethylsilyl)amides react with fluoro-, bromo-, and chlorobenzenes in THF or toluene to give a mixture of N,N-bis(trimethylsilyl)aniline and N,2-bis(trimethylsilyl)aniline. The latter compound is resulted from 1,3-shift of the trimethylsilyl group from nitrogen to ortho-carbon atom of the benzene ring. Effects of the solvent, halogen, and alkali metal nature as well as the reaction conditions on the ratio of isomers were examined. Reaction of iodobenzene with sodium bis(trimethylsilyl)amide in THF produces N,N-bis(trimethylsilyl)aniline and 2-iodo-N,N-bis(trimethylsilyl)aniline, while in toluene a mixture of three products, two indicated above and N,N-bis(trimethylsilyl)benzylamine, was obtained.

N-substituted hexamethyldisilazanes as new substances for the synthesis of functional films in the system Si-Ge-C-N-H

N-Organylbis(trimethylsilyl)amines of the general formula RN(SiMe3)2 (R = Me3Si, Et3Ge) were synthesized by reaction of sodium bis(trimethylsilyl)amide with the corresponding trialkylsilyl(germyl) halide. Their IR, UV, and 1H, 13C, and 29Si NMR spectra were studied, and saturated vapor pressures and thermal stabilities were determined. The possibility of using the RN(SiMe3)2 compounds as precursors in chemical vapor deposition of films with specified composition was estimated by thermodynamic modeling.

Synthesis of volatile bis[bis(trimethylsilyl)amide]-substituted boron derivatives

General strategy for the synthesis of organoboron compounds containing bis(trimethylsilyl)amide substituents has been suggested.

Reaction of sodium bis(trimethylsilyl)amide with 2-bromopyridine

A reaction of sodium bis(trimethylsilyl)amide with 2-bromopyridine leads to N,N-bis(trimethylsilyl)- and N,3-bis(trimethylsilyl)-2-pyridinamine.