Names | |
---|---|
Preferred IUPAC name
2,2,4,4,6,6-hexamethyl-1,3,5,2,4,6-triazatrisilinane | |
Other names
1,1,3,3,5,5-Hexamethyl-2,4,6,1,3,5-triazatrisilinane; 2,4,4,6,6-Hexamethyl-1,3,5-triaza-2,4,6-trisilacyclohexane; Dimethylsilazane trimer; HMCTS; HCMTSZ
| |
Identifiers | |
3D model (
JSmol)
|
|
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.012.521 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C6H21N3Si3 | |
Molar mass | 219.510 g·mol−1 |
Density | d20 0.9196 g/mL [1] |
Melting point | −10 °C [1] [2] |
Boiling point | 188 °C [1] [2] |
Refractive index (nD)
|
n20/D 1.445 [1] |
Hazards | |
GHS labelling: | |
Danger | |
H226, H302, H314, H315, H319, H335 | |
P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P330, P332+P313, P337+P313, P362, P363, P370+P378, P403+P233, P403+P235, P405, P501 | |
Flash point | 59 °C; 139 °F; 333 K |
Lethal dose or concentration (LD, LC): | |
LD50 (
median dose)
|
500 mg/kg (rat) [2] |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Hexamethylcyclotrisilazane
[3] is a
chemical compound with
formula C
6H
21N
3Si
3 or [–Si(CH
3)
2–NH–]
3. Its
molecule consists of a six-member ring of three
silicon atoms alternating with three
nitrogen atoms, with two
methyl groups bonded to each silicon and one
hydrogen atom bonded to each nitrogen. It can be described as a derivative of the
hypothetical compound
cyclotrisilazane [–SiH
2–NH–]
3, or as a
cyclic
trimer of hypothetical
dimethylsilazane (CH
3)
2SiNH.
[2]
[4]
The compound is a clear colorless liquid at room temperature. [2]
The compound has been extensively studied because of its applications in the semiconductor industry, as a precursor for the deposition of fils of silicon nitride [5] [6] [7] and silicon carbonitride [8] and as an additive in photoresist formulations. It has also been proposed as an additive to silica for liquid chromatography. [9]
Other names for the compound are 2,2,4,4,6,6-hexamethyl-1,3,5,2,4,6-triazatrisilinane ( IUPAC), 1,1,3,3,5,5-hexamethyl-2,4,6,1,3,5-triazatrisilinane, and 2,4,4,6,6-hexamethyl-1,3,5-triaza-2,4,6-trisilacyclohexane. [2] The name is often abbreviated HMCTS [3] or HMCTSZN. [7]
The silicon-nitrogen ring is nearly planar. The interatomic distances are: Si-N = 1.728 Å, Si-C = 1.871 Å, C-H = 1.124 Å. The approximate bond angles are N-Si-N ≈ 108°, Si-N-Si ≈ 127°, C-Si-C ≈ 109°, H-C-H ≈ 112°. [10] [11]
The compound was obtained in 1948 by Brewer and Haber by introducing
dimethyldichlorosilane Si(CH
3)
2Cl
2 into liquid
ammonia NH
3, and then extracting the precipitate with
benzene. The reaction yields a mixture of compounds, chiefly the trimer and the
tetramer
octamethyltetrasilazane. The trimer can be separated from the other products by fractional distillation.
[1]
The yield can be improved by converting the tetramer, through reaction with hydrogen in the presence of suitable catalysts. [12] [13]
Names | |
---|---|
Preferred IUPAC name
2,2,4,4,6,6-hexamethyl-1,3,5,2,4,6-triazatrisilinane | |
Other names
1,1,3,3,5,5-Hexamethyl-2,4,6,1,3,5-triazatrisilinane; 2,4,4,6,6-Hexamethyl-1,3,5-triaza-2,4,6-trisilacyclohexane; Dimethylsilazane trimer; HMCTS; HCMTSZ
| |
Identifiers | |
3D model (
JSmol)
|
|
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.012.521 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C6H21N3Si3 | |
Molar mass | 219.510 g·mol−1 |
Density | d20 0.9196 g/mL [1] |
Melting point | −10 °C [1] [2] |
Boiling point | 188 °C [1] [2] |
Refractive index (nD)
|
n20/D 1.445 [1] |
Hazards | |
GHS labelling: | |
Danger | |
H226, H302, H314, H315, H319, H335 | |
P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P330, P332+P313, P337+P313, P362, P363, P370+P378, P403+P233, P403+P235, P405, P501 | |
Flash point | 59 °C; 139 °F; 333 K |
Lethal dose or concentration (LD, LC): | |
LD50 (
median dose)
|
500 mg/kg (rat) [2] |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Hexamethylcyclotrisilazane
[3] is a
chemical compound with
formula C
6H
21N
3Si
3 or [–Si(CH
3)
2–NH–]
3. Its
molecule consists of a six-member ring of three
silicon atoms alternating with three
nitrogen atoms, with two
methyl groups bonded to each silicon and one
hydrogen atom bonded to each nitrogen. It can be described as a derivative of the
hypothetical compound
cyclotrisilazane [–SiH
2–NH–]
3, or as a
cyclic
trimer of hypothetical
dimethylsilazane (CH
3)
2SiNH.
[2]
[4]
The compound is a clear colorless liquid at room temperature. [2]
The compound has been extensively studied because of its applications in the semiconductor industry, as a precursor for the deposition of fils of silicon nitride [5] [6] [7] and silicon carbonitride [8] and as an additive in photoresist formulations. It has also been proposed as an additive to silica for liquid chromatography. [9]
Other names for the compound are 2,2,4,4,6,6-hexamethyl-1,3,5,2,4,6-triazatrisilinane ( IUPAC), 1,1,3,3,5,5-hexamethyl-2,4,6,1,3,5-triazatrisilinane, and 2,4,4,6,6-hexamethyl-1,3,5-triaza-2,4,6-trisilacyclohexane. [2] The name is often abbreviated HMCTS [3] or HMCTSZN. [7]
The silicon-nitrogen ring is nearly planar. The interatomic distances are: Si-N = 1.728 Å, Si-C = 1.871 Å, C-H = 1.124 Å. The approximate bond angles are N-Si-N ≈ 108°, Si-N-Si ≈ 127°, C-Si-C ≈ 109°, H-C-H ≈ 112°. [10] [11]
The compound was obtained in 1948 by Brewer and Haber by introducing
dimethyldichlorosilane Si(CH
3)
2Cl
2 into liquid
ammonia NH
3, and then extracting the precipitate with
benzene. The reaction yields a mixture of compounds, chiefly the trimer and the
tetramer
octamethyltetrasilazane. The trimer can be separated from the other products by fractional distillation.
[1]
The yield can be improved by converting the tetramer, through reaction with hydrogen in the presence of suitable catalysts. [12] [13]