Hexamethyldisilazane

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  • Identifiers

    CAS number
    999-97-3

    Molecular formula
    C6H19NSi2

    SMILES
    C[Si](C)(C)N[Si](C)(C)C

    Safety labels

    Flammable
    Flammable

    Corrosive
    Corrosive

    Acute Toxic
    Acute Toxic

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Fishy 43.07%
    Sulfurous 29.29%
    Odorless 26.57%
    Mint 25.32%
    Ripe 23.11%
    Cheesy 22.55%
    Cooling 19.94%
    Woody 19.0%
    Fresh 17.16%
    Camphoreous 16.79%

     

    Flavor
    Green 23.62%
    Mild 23.6%
    Pungent 20.79%
    Yeasty 19.45%
    Catty 18.98%
    Black currant 18.95%
    Blackberry 18.83%
    Bloody 18.55%
    Terpenic 18.46%
    Cat-urine 18.37%

     

    Odor impact est.
    Low

  • Properties

    pKa est.
    8.37 (weak base)

    Molecular weight
    161.39 g/mol

    Boiling point

    • 125 °C

    Flash point

    • 14.66 ˚C est.
    • 48 °F (NFPA, 2010)
    • 27 °C
    • 81 °F (27 °C) closed cup
    • 14 °C (closed cup) /from table/

    Solubility expt.

    • Soluble in acetone, benzene, ethyl ether, heptane, perchloroethylene
    • Insol in water, reacts slowly
    • In water, 392 mg/l @ 25 °C /Estimated/

  • Synonyms

    • Hexamethyldisilazane
    • 999-97-3
    • Bis(trimethylsilyl)amine
    • HMDS
    • 1,1,1,3,3,3-Hexamethyldisilazane
    • Hexamethylsilazane
    • 1,1,1-Trimethyl-N-(trimethylsilyl)silanamine
    • Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-
    • TSL 8802
    • hexamethyl disilazane
    • Disilazane, 1,1,1,3,3,3-hexamethyl-
    • SZ 6079
    • H36C68P1BH
    • DTXSID2025395
    • NSC-93895
    • DTXCID805395
    • CHEBI:85068
    • RefChem:146076
    • 213-668-5
    • sodium hexamethyldisilazide
    • [dimethyl-(trimethylsilylamino)silyl]methane
    • hexamethyldisilylamine
    • MFCD00008259
    • NSC 93895
    • (TMS)2NH
    • hexamethyldisilizane
    • Hexamethyl disilylamine
    • ((CH3)3Si)2NH
    • OAP
    • 1,1,3,3,3-Hexamethyldisilazane
    • Trimethyl-N-(trimethylsilyl)silanamine
    • 1,1,1,3,3,3-HEXAMETHYL-DISILAZANE
    • Lithium hexamethyldisilazane
    • CCRIS 2456
    • HSDB 7226
    • bis(trimethylsilyl)amine;[dimethyl-(trimethylsilylamino)silyl]methane
    • EINECS 213-668-5
    • Lithium tris(trimethylsilyl)amine
    • CAS-999-97-3
    • NSC-252161
    • UNII-H36C68P1BH
    • AI3-51467
    • hexamethyldisilazan
    • hexamethyidisilazane
    • hexa-methyldisilazane
    • hexamethyl-disilazane
    • bistrimethylsilylamine
    • Me3SiNHSiMe3
    • bis-(trimethylsilyl)amine
    • (Me3Si)2NH
    • EC 213-668-5
    • DISILAZANE,HEXAMETHYL
    • HN(TMS)2
    • SCHEMBL7649
    • SCHEMBL50048
    • orb2939726
    • CHEMBL3183662
    • HEXAMETHYLDISILAZANE [MI]
    • 1,1,3,3,3-hexamethyidisilazane
    • HEXAMETHYLDISILAZANE [HSDB]
    • STR02905
    • 1,1,1,3,3,3-hexamethyldisilazan
    • Tox21_202428
    • Tox21_303281
    • 1,1,1,3,3,3 hexamethyldisilazane
    • 1,1,1,3,3,3-hexamethyidisilazane
    • 1,1,1.3,3,3-hexamethyldisilazane
    • NSC252161
    • STL185550
    • Disilazane,1,1,3,3,3-hexamethyl-
    • 1,1,1, 3,3,3-hexamethyldisilazane
    • 1,1,1,3,3,3,-hexamethyldisilazane
    • AKOS000120987
    • NCGC00164366-01
    • NCGC00164366-02
    • NCGC00257230-01
    • NCGC00259977-01
    • BP-21394
    • H0089
    • Hexamethyldisilazane, reagent grade, >=99%
    • NS00043130
    • Hexamethyldisilazane, ReagentPlus(R), 99.9%
    • Silanamine,1,1-trimethyl-N-(trimethylsilyl)-
    • WLN: 1-SI-1&1&M-SI-1&1&1
    • S09625
    • Disilazane,1,1,3,3,3-hexamethyl-, lithium salt
    • Q425001
    • F0001-2345
    • Silanamine,1,1-trimethyl-N-(trimethylsilyl)-, lithium salt
    • Hexamethyldisilazane, for GC derivatization, >=99.0% (GC)
    • InChI=1/C6H19NSi2/c1-8(2,3)7-9(4,5)6/h7H,1-6H
    • 1,1,1,3,3,3-Hexamethyldisilazane; 1,1,1-Trimethyl-N-(trimethylsilyl)silanamine
    • Hexamethyldisilazane, produced by Wacker Chemie AG, Burghausen, Germany, >=97.0% (GC)
    • 27495-70-1
    • 999-97-3

  • Applications

    Hexamethyldisilazane (CAS 999-97-3) is widely used as a silylating reagent and moisture scavenger in chemical processing. In electronics and coatings, it is used to treat oxide surfaces (such as silicon dioxide or glass) to form hydrophobic, silanized interfaces that improve adhesion of photoresists, coatings, and subsequent metal or polymer layers. In organic synthesis it serves as a protecting-group reagent, converting alcohols and amines into trimethylsilyl ethers and related aminosilyl derivatives, enabling selective transformations. It is also used to dry solvents and glassware, helping remove residual water before sensitive steps. In polymer and composite manufacturing it can act as a silane source for surface modification, altering surface energy and processing behavior. It may be used or evaluated as an intermediate in the preparation of silane coupling agents, subject to formulation needs and local regulations.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 500.34
    methanol 666.63
    isopropanol 282.32
    water 9.36
    ethyl acetate 346.04
    n-propanol 397.42
    acetone 465.5
    n-butanol 298.75
    acetonitrile 208.97
    DMF 456.84
    toluene 226.8
    isobutanol 210.65
    1,4-dioxane 585.38
    methyl acetate 303.1
    THF 1447.02
    2-butanone 377.91
    n-pentanol 196.15
    sec-butanol 242.97
    n-hexane 159.37
    ethylene glycol 135.62
    NMP 665.85
    cyclohexane 295.54
    DMSO 446.59
    n-butyl acetate 366.76
    n-octanol 197.6
    chloroform 381.5
    n-propyl acetate 210.94
    acetic acid 318.27
    dichloromethane 325.4
    cyclohexanone 614.18
    propylene glycol 179.5
    isopropyl acetate 227.22
    DMAc 339.75
    2-ethoxyethanol 247.22
    isopentanol 173.06
    n-heptane 219.07
    ethyl formate 219.94
    1,2-dichloroethane 251.65
    n-hexanol 402.58
    2-methoxyethanol 478.85
    isobutyl acetate 142.62
    tetrachloromethane 147.71
    n-pentyl acetate 253.84
    transcutol 462.29
    n-heptanol 221.32
    ethylbenzene 80.86
    MIBK 199.63
    2-propoxyethanol 543.6
    tert-butanol 235.84
    MTBE 254.11
    2-butoxyethanol 281.69
    propionic acid 303.67
    o-xylene 127.15
    formic acid 162.08
    diethyl ether 449.17
    m-xylene 156.08
    p-xylene 103.38
    chlorobenzene 188.89
    dimethyl carbonate 133.01
    n-octane 78.05
    formamide 165.64
    cyclopentanone 841.33
    2-pentanone 367.89
    anisole 141.3
    cyclopentyl methyl ether 639.16
    gamma-butyrolactone 730.02
    1-methoxy-2-propanol 354.57
    pyridine 354.12
    3-pentanone 306.02
    furfural 431.3
    n-dodecane 43.15
    diethylene glycol 308.05
    diisopropyl ether 152.34
    tert-amyl alcohol 194.14
    acetylacetone 311.16
    n-hexadecane 47.58
    acetophenone 135.44
    methyl propionate 298.3
    isopentyl acetate 263.99
    trichloroethylene 331.76
    n-nonanol 172.39
    cyclohexanol 334.46
    benzyl alcohol 114.08
    2-ethylhexanol 235.83
    isooctanol 143.41
    dipropyl ether 399.63
    1,2-dichlorobenzene 142.12
    ethyl lactate 103.9
    propylene carbonate 356.38
    n-methylformamide 309.05
    2-pentanol 199.24
    n-pentane 167.45
    1-propoxy-2-propanol 396.43
    1-methoxy-2-propyl acetate 326.68
    2-(2-methoxypropoxy) propanol 151.81
    mesitylene 108.91
    ε-caprolactone 459.77
    p-cymene 110.19
    epichlorohydrin 445.93
    1,1,1-trichloroethane 226.76
    2-aminoethanol 235.91
    morpholine-4-carbaldehyde 444.59
    sulfolane 657.03
    2,2,4-trimethylpentane 49.81
    2-methyltetrahydrofuran 711.43
    n-hexyl acetate 291.8
    isooctane 43.98
    2-(2-butoxyethoxy)ethanol 239.19
    sec-butyl acetate 136.8
    tert-butyl acetate 233.87
    decalin 70.77
    glycerin 214.36
    diglyme 393.98
    acrylic acid 230.41
    isopropyl myristate 115.45
    n-butyric acid 343.95
    acetyl acetate 215.89
    di(2-ethylhexyl) phthalate 95.18
    ethyl propionate 184.14
    nitromethane 338.9
    1,2-diethoxyethane 285.12
    benzonitrile 137.98
    trioctyl phosphate 92.58
    1-bromopropane 258.88
    gamma-valerolactone 664.53
    n-decanol 126.67
    triethyl phosphate 101.81
    4-methyl-2-pentanol 107.12
    propionitrile 201.22
    vinylene carbonate 256.36
    1,1,2-trichlorotrifluoroethane 286.65
    DMS 166.82
    cumene 66.05
    2-octanol 151.46
    2-hexanone 224.59
    octyl acetate 152.16
    limonene 197.14
    1,2-dimethoxyethane 332.57
    ethyl orthosilicate 107.03
    tributyl phosphate 99.56
    diacetone alcohol 211.97
    N,N-dimethylaniline 111.22
    acrylonitrile 190.09
    aniline 214.76
    1,3-propanediol 256.11
    bromobenzene 174.1
    dibromomethane 306.76
    1,1,2,2-tetrachloroethane 279.55
    2-methyl-cyclohexyl acetate 183.12
    tetrabutyl urea 136.22
    diisobutyl methanol 118.21
    2-phenylethanol 193.75
    styrene 97.78
    dioctyl adipate 124.93
    dimethyl sulfate 168.03
    ethyl butyrate 232.2
    methyl lactate 162.15
    butyl lactate 182.18
    diethyl carbonate 127.09
    propanediol butyl ether 213.73
    triethyl orthoformate 182.11
    p-tert-butyltoluene 120.46
    methyl 4-tert-butylbenzoate 167.18
    morpholine 635.03
    tert-butylamine 180.15
    n-dodecanol 99.56
    dimethoxymethane 456.24
    ethylene carbonate 253.1
    cyrene 156.02
    2-ethoxyethyl acetate 264.0
    2-ethylhexyl acetate 250.79
    1,2,4-trichlorobenzene 163.45
    4-methylpyridine 303.4
    dibutyl ether 239.1
    2,6-dimethyl-4-heptanol 118.21
    DEF 317.61
    dimethyl isosorbide 308.28
    tetrachloroethylene 242.28
    eugenol 145.18
    triacetin 194.23
    span 80 199.82
    1,4-butanediol 105.86
    1,1-dichloroethane 243.87
    2-methyl-1-pentanol 117.95
    methyl formate 241.47
    2-methyl-1-butanol 182.93
    n-decane 78.23
    butyronitrile 214.39
    3,7-dimethyl-1-octanol 145.13
    1-chlorooctane 153.07
    1-chlorotetradecane 66.38
    n-nonane 84.37
    undecane 55.81
    tert-butylcyclohexane 63.88
    cyclooctane 127.23
    cyclopentanol 422.62
    tetrahydropyran 757.18
    tert-amyl methyl ether 217.98
    2,5,8-trioxanonane 252.07
    1-hexene 215.74
    2-isopropoxyethanol 162.31
    2,2,2-trifluoroethanol 131.61
    methyl butyrate 210.75

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction