| |
| Names | |
|---|---|
|
Preferred IUPAC name
2-Methylpentane-2,4-diol | |
| Other names
2-Methyl-2,4-pentanediol
Hexylene glycol Diolane 1,1,3-Trimethyltrimethylenediol 2,4-Dihydroxy-2-methylpentane Isol | |
| Identifiers | |
| |
3D model (
JSmol)
|
|
| Abbreviations | MPD |
| 1098298 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.003.173 |
| EC Number |
|
PubChem
CID
|
|
| RTECS number |
|
| UNII | |
| UN number | 1993 |
CompTox Dashboard (
EPA)
|
|
| |
| |
| Properties | |
| C6H14O2 | |
| Molar mass | 118.176 g·mol−1 |
| Appearance | colourless liquid |
| Odor | mild, sweetish [1] |
| Density | 0.92 g/mL |
| Melting point | −40 °C (−40 °F; 233 K) |
| Boiling point | 197 °C (387 °F; 470 K) |
| miscible [1] | |
| Vapor pressure | 0.05 mmHg (20°C) [1] |
| Hazards | |
| GHS labelling: [3] | |
| |
| Warning | |
| H315, H319 | |
| P264, P264+P265, P280, P302+P352, P305+P351+P338, P321, P332+P317, P337+P317, P362+P364 | |
| Flash point | 98.3 °C (208.9 °F; 371.4 K) [2] |
| Explosive limits | 1.3%-7.4% [1] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
|
none [1] |
REL (Recommended)
|
C 25 ppm (125 mg/m3) [1] |
IDLH (Immediate danger)
|
N.D. [1] |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
| |
2-Methyl-2,4-pentanediol (MPD) is an organic compound with the formula (CH3)2C(OH)CH2CH(OH)CH3. This colourless liquid is a chiral diol. It is produced industrially from diacetone alcohol by hydrogenation. [4] Total European and USA production was 15000 tonnes in 2000. [5]
2-Methyl-2,4-pentanediol exists as two enantiomers, (4R)-(−) and (4S)-(+). In the Protein Data Bank, the 3-letter code "MPD" refers to the (S)-(−) enantiomer, while "MRD" is used to refer to the (R)-(+) version. Commercial products labeled "MPD" are usually the racemate, [6] also sold as and referred to as "hexylene glycol". [7] [8]
2-Methyl-2,4-pentanediol exhibits both surfactant and emulsion-stabilizing properties. Its relatively high viscosity and low volatility are advantageous in coatings, cleansers, cosmetics, solvents, lubricants, and hydraulic fluids. [9] Although it is an irritant at higher concentrations, it is sometimes used in skin care, hair care, soap, and eye cosmetic products at concentrations ranging from 0.1% - 25%. [10] [11]
It is biodegradable and unlikely to accumulate in the environment. [12]
In the laboratory it is a common precipitant and cryoprotectant in protein crystallography. [13] Since hexylene glycol is compatible with polar and nonpolar molecules, it competes with the solvent in a crystallography experiment causing the protein to precipitate. [14] Hexylene glycol is so effective in protein crystallography because its amphiphilic nature and small, flexible structure allows it to bind to many different locations on a protein secondary structure including alpha helices and beta sheets. [15] When hexylene glycol binds to these different locations, water is removed and the protein crystals anneal, which prevents ice formation during cryocrystallography techniques. [16] Incorporation of hexylene glycol into solution has been known to improve the resolution of X-ray diffraction making protein structures easily identifiable. [17] Additionally hexylene glycol is not a strong denaturing agent and thus does not significantly alter the structure of a protein during the crystallography procedure. [15]
Hexylene glycol is also used as a lubricant for polishing specimens in metallography. [18]
Like related diols, it forms borate esters.
- ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0328". National Institute for Occupational Safety and Health (NIOSH).
- ^ CDC - NIOSH Pocket Guide to Chemical Hazards
- ^ "Hexylene Glycol". pubchem.ncbi.nlm.nih.gov.
- ^ Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi: 10.1002/14356007.a01_079.pub3
- ^ SIDS Initial Assessment Report for SIAM 13: Hexylene Glycol
- ^ MPD at Hampton Research , MPD Product Page
- ^ Hexylene Glycol at Sigma Aldrich , Hexylene Glycol Product Page
- ^ Hexylene Glycol at Jena Bioscience, Hexylene Glycol Product Page
- ^ Chemicalland21.com Hexylene glycol
- ^ Kinnunen, T. (1991). "Antibacterial and antifungal properties of propylene glycol, and 1,3-butylene glycol in vitro". Acta Dermato-Venereologica. doi: 10.2340/0001555571148150. S2CID 13239472.
- ^ R. Rietschel; J. Fowler; A. Fisher Hexylene Glycol. In Fisher's Contact Dermatitis; Holmes, M., Ed.; BC Decker Inc.: Hamilton,Ontario, 2008; pp 290
- ^ Rhodia Hexylene glycol GPS Safety Summary. 2012.
- ^ Crystallization Techniques: Additives, Enrico Stura, University of Glasgow
- ^ Dumetz, A. (2009). "Comparative Effects of Salt, Organic and Polymer Precipitants on Protein Phase Behavior and Implications for Vapor Diffusion". J. Cryst. Growth. 9 (2): 682–691. doi: 10.1021/cg700956b.
- ^ a b Anand, K (2002). "An overview on 2-methyl-2,4-pentanediol in crystallization and in crystals of biological macromolecules". Acta Crystallogr. 58 (10): 1722–1728. Bibcode: 2002AcCrD..58.1722A. doi: 10.1107/s0907444902014610. PMC 7161645. PMID 12351894.
- ^ Viatcheslav, Berejnov (2006). "Thornea Effects of cryoprotectant concentration and cooling rate on vitrification of aqueous solutions". J. Appl. Crystallogr.
- ^ Vera, L (2006). "Strategies for Protein Crystallography". Cryst. Growth Des.
-
^
"GreenLube". Allied High Tech. Retrieved 2023-09-23.
GreenLube is a medium viscosity hexylene glycol based lubricant used for general metallographic preparation
|
| |
| Names | |
|---|---|
|
Preferred IUPAC name
2-Methylpentane-2,4-diol | |
| Other names
2-Methyl-2,4-pentanediol
Hexylene glycol Diolane 1,1,3-Trimethyltrimethylenediol 2,4-Dihydroxy-2-methylpentane Isol | |
| Identifiers | |
| |
3D model (
JSmol)
|
|
| Abbreviations | MPD |
| 1098298 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.003.173 |
| EC Number |
|
PubChem
CID
|
|
| RTECS number |
|
| UNII | |
| UN number | 1993 |
CompTox Dashboard (
EPA)
|
|
| |
| |
| Properties | |
| C6H14O2 | |
| Molar mass | 118.176 g·mol−1 |
| Appearance | colourless liquid |
| Odor | mild, sweetish [1] |
| Density | 0.92 g/mL |
| Melting point | −40 °C (−40 °F; 233 K) |
| Boiling point | 197 °C (387 °F; 470 K) |
| miscible [1] | |
| Vapor pressure | 0.05 mmHg (20°C) [1] |
| Hazards | |
| GHS labelling: [3] | |
|
| |
| Warning | |
| H315, H319 | |
| P264, P264+P265, P280, P302+P352, P305+P351+P338, P321, P332+P317, P337+P317, P362+P364 | |
| Flash point | 98.3 °C (208.9 °F; 371.4 K) [2] |
| Explosive limits | 1.3%-7.4% [1] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
|
none [1] |
REL (Recommended)
|
C 25 ppm (125 mg/m3) [1] |
IDLH (Immediate danger)
|
N.D. [1] |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
| |
2-Methyl-2,4-pentanediol (MPD) is an organic compound with the formula (CH3)2C(OH)CH2CH(OH)CH3. This colourless liquid is a chiral diol. It is produced industrially from diacetone alcohol by hydrogenation. [4] Total European and USA production was 15000 tonnes in 2000. [5]
2-Methyl-2,4-pentanediol exists as two enantiomers, (4R)-(−) and (4S)-(+). In the Protein Data Bank, the 3-letter code "MPD" refers to the (S)-(−) enantiomer, while "MRD" is used to refer to the (R)-(+) version. Commercial products labeled "MPD" are usually the racemate, [6] also sold as and referred to as "hexylene glycol". [7] [8]
2-Methyl-2,4-pentanediol exhibits both surfactant and emulsion-stabilizing properties. Its relatively high viscosity and low volatility are advantageous in coatings, cleansers, cosmetics, solvents, lubricants, and hydraulic fluids. [9] Although it is an irritant at higher concentrations, it is sometimes used in skin care, hair care, soap, and eye cosmetic products at concentrations ranging from 0.1% - 25%. [10] [11]
It is biodegradable and unlikely to accumulate in the environment. [12]
In the laboratory it is a common precipitant and cryoprotectant in protein crystallography. [13] Since hexylene glycol is compatible with polar and nonpolar molecules, it competes with the solvent in a crystallography experiment causing the protein to precipitate. [14] Hexylene glycol is so effective in protein crystallography because its amphiphilic nature and small, flexible structure allows it to bind to many different locations on a protein secondary structure including alpha helices and beta sheets. [15] When hexylene glycol binds to these different locations, water is removed and the protein crystals anneal, which prevents ice formation during cryocrystallography techniques. [16] Incorporation of hexylene glycol into solution has been known to improve the resolution of X-ray diffraction making protein structures easily identifiable. [17] Additionally hexylene glycol is not a strong denaturing agent and thus does not significantly alter the structure of a protein during the crystallography procedure. [15]
Hexylene glycol is also used as a lubricant for polishing specimens in metallography. [18]
Like related diols, it forms borate esters.
- ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0328". National Institute for Occupational Safety and Health (NIOSH).
- ^ CDC - NIOSH Pocket Guide to Chemical Hazards
- ^ "Hexylene Glycol". pubchem.ncbi.nlm.nih.gov.
- ^ Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi: 10.1002/14356007.a01_079.pub3
- ^ SIDS Initial Assessment Report for SIAM 13: Hexylene Glycol
- ^ MPD at Hampton Research , MPD Product Page
- ^ Hexylene Glycol at Sigma Aldrich , Hexylene Glycol Product Page
- ^ Hexylene Glycol at Jena Bioscience, Hexylene Glycol Product Page
- ^ Chemicalland21.com Hexylene glycol
- ^ Kinnunen, T. (1991). "Antibacterial and antifungal properties of propylene glycol, and 1,3-butylene glycol in vitro". Acta Dermato-Venereologica. doi: 10.2340/0001555571148150. S2CID 13239472.
- ^ R. Rietschel; J. Fowler; A. Fisher Hexylene Glycol. In Fisher's Contact Dermatitis; Holmes, M., Ed.; BC Decker Inc.: Hamilton,Ontario, 2008; pp 290
- ^ Rhodia Hexylene glycol GPS Safety Summary. 2012.
- ^ Crystallization Techniques: Additives, Enrico Stura, University of Glasgow
- ^ Dumetz, A. (2009). "Comparative Effects of Salt, Organic and Polymer Precipitants on Protein Phase Behavior and Implications for Vapor Diffusion". J. Cryst. Growth. 9 (2): 682–691. doi: 10.1021/cg700956b.
- ^ a b Anand, K (2002). "An overview on 2-methyl-2,4-pentanediol in crystallization and in crystals of biological macromolecules". Acta Crystallogr. 58 (10): 1722–1728. Bibcode: 2002AcCrD..58.1722A. doi: 10.1107/s0907444902014610. PMC 7161645. PMID 12351894.
- ^ Viatcheslav, Berejnov (2006). "Thornea Effects of cryoprotectant concentration and cooling rate on vitrification of aqueous solutions". J. Appl. Crystallogr.
- ^ Vera, L (2006). "Strategies for Protein Crystallography". Cryst. Growth Des.
-
^
"GreenLube". Allied High Tech. Retrieved 2023-09-23.
GreenLube is a medium viscosity hexylene glycol based lubricant used for general metallographic preparation