DBDMH (also known as 1,3-Dibromo-5,5-Dimethylhydantoin) is an organic compound derived from the heterocycle called dimethylhydantoin. This white crystalline compound with a slight bromine odor is widely used as a disinfectant used for drinking water purification, recreational water treatment, as a bleaching agent in pulp and paper mills, and for treating industrial/commercial water cooling systems. [1] Its action does not involve the use of hypochlorous acid.

1,3-Dibromo-5,5-Dimethylhydantoin
Skeletal formula of DBDMH
Ball-and-stick model of the DBDMH molecule
Names
Preferred IUPAC name
1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione
Other names
DBDMH, Dibromantin, Dibromodimethylhydantoin
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.000.938 Edit this at Wikidata
EC Number
  • 201-030-9
UNII
  • InChI=1S/C5H6Br2N2O2/c1-5(2)3(10)8(6)4(11)9(5)7/h1-2H3 checkY
    Key: VRLDVERQJMEPIF-UHFFFAOYSA-N checkY
  • InChI=1/C5H6Br2N2O2/c1-5(2)3(10)8(6)4(11)9(5)7/h1-2H3
    Key: VRLDVERQJMEPIF-UHFFFAOYAQ
  • O=C1N(Br)C(=O)N(Br)C1(C)C
Properties
C5H6Br2N2O2
Molar mass 285.923 g·mol−1
Appearance White solid
Density 1.36 g/cm3
Melting point 197 to 203 °C (387 to 397 °F; 470 to 476 K)
0.1 g/100 mL (20 °C)
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation markGHS09: Environmental hazard
Danger
H301, H302, H314, H317, H319, H410
P260, P261, P264, P270, P272, P273, P280, P301+P310, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P333+P313, P337+P313, P363, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Mechanism of action

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1,3-Dibromo-5,5-Dimethylhydantoin is a source of bromine, which is equivalent to hypobromous acid (HOBr).

Br2X + 2 H2O → 2 HOBr + H2X

(Where H2X is 5,5-dimethylhydantoin)

With a pKa of 8.6, hypobromous acid partially dissociates in water:

HOBr ⇌ H+ + BrO

Hypobromous acid serves as a source of "Br+," which produces bromide ions in the process of disinfection:

HOBr + live pathogens → Br + dead pathogens

The resulting bromide ions can then undergo oxidation to hypobromous acid in the presence of an oxidizer of sufficient strength e.g. ozone, hypochlorous acid, potassium monopersulfate. This reoxidation process is commonly called "activation" of the bromide ion:

Br + HOCl → HOBr + Cl

References

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  1. ^ David Ioffe, Arieh Kampf "Bromine, Organic Compounds" in Kirk-Othmer Encyclopedia of Chemical Technology, 2002, by John Wiley & Sons. doi:10.1002/0471238961.0218151325150606.a01
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