Diethyl dithiophosphoric acid

Diethyl dithiophosphoric acid, sometimes mistakenly called diethyl dithiophosphate, is the organophosphorus compound with the formula (C2H5O)2PS2H. It is the processor for production of the organophosphate insecticide Terbufos. Although samples can appear dark, it is a colorless liquid.[1]

Diethyl dithiophosphoric acid
Names
Preferred IUPAC name
O,O-Diethyl hydrogen phosphorodithioate
Other names
O,O-Diethyl dithiophosphoric acid; Diethyl dithiophosphate; Diethyl phosphorodithioate; Diethyl ester of phosphorodithioic acid
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.005.506 Edit this at Wikidata
EC Number
  • 206-055-9
RTECS number
  • TD7350000
UNII
  • InChI=1S/C4H11O2PS2/c1-3-5-7(8,9)6-4-2/h3-4H2,1-2H3,(H,8,9)
    Key: IRDLUHRVLVEUHA-UHFFFAOYSA-N
  • InChI=1/C4H11O2PS2/c1-3-5-7(8,9)6-4-2/h3-4H2,1-2H3,(H,8,9)
    Key: IRDLUHRVLVEUHA-UHFFFAOYAW
  • CCOP(=S)(OCC)S
Properties
C4H11O2PS2
Molar mass 186.22 g·mol−1
Appearance colorless liquid
Melting point < 0 °C (32 °F; 273 K)
Boiling point 66 °C (151 °F; 339 K) at 1 mmHg
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: Toxic
Danger
H301, H311, H314, H330
P260, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P320, P321, P322, P330, P361, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
2
1
Flash point 82 °C (180 °F; 355 K)
538 °C (1,000 °F; 811 K)
Lethal dose or concentration (LD, LC):
500 mg/kg (rabbit, dermal)
4510 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

It is prepared by treating phosphorus pentasulfide with ethanol:[2]

P2S5 + 4 C2H5OH → 2 (C2H5O)2PS2H + H2S

Reactions edit

 
Zinc dithiophosphate.

Diethyl- and dimethyl dithiophosphoric acids react with bases. The results of this neutralization reaction are salts, e.g., ammonium diethyl dithiophosphate.[3]

Diethyl dithiophosphoric acid reacts with zinc oxide to give zinc dithiophosphate, which is used as an oil additive:[4]

ZnO + 2 (C2H5O)2PS2H → [(C2H5O)2PS2]2Zn + H2O

See also edit

References edit

  1. ^ J. Svara, N. Weferling, T. Hofmann "Phosphorus Compounds, Organic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2006. doi:10.1002/14356007.a19_545.pub2
  2. ^ Lefferts, J. L.; Molloy, K. C.; Zuckerman, J. J.; Haiduc, I.; Guta, C.; Ruse, D. (1980). "Oxy and thio phosphorus acid derivatives of tin. 1. Triorganotin(IV) dithiophosphate esters". Inorganic Chemistry. 19 (6): 1662–1670. doi:10.1021/ic50208a046.
  3. ^ Okuniewski, Andrzej; Becker, Barbara (2011). "Ammonium O,O′-diethyl dithiophosphate". Acta Crystallogr. E. 67 (7): o1749–o1750. doi:10.1107/S1600536811022811. PMC 3151957. PMID 21837134.
  4. ^ H. Spikes "The history and mechanisms of ZDDP" Tribology Letters, Vol. 17, No. 3, October 2004. doi:10.1023/B:TRIL.0000044495.26882.b5.