1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH or bromochlorodimethylhydantoin) is a chemical structurally related to hydantoin. It is a white crystalline compound with a slight bromine and acetone odor and is insoluble in water, but soluble in acetone.

BCDMH
Skeletal formula of BCDMH
Ball-and-stick model of BCDMH
Laboratory sample of BCDMH
Names
Preferred IUPAC name
1-Bromo-3-chloro-5,5-dimethylimidazolidine-2,4-dione
Other names
bromochloro-5,5-dimethylhydantoin, BCDMH, agribrom, aquabrom, aquabrome, bromicide, bromochlorodimethylhydantoin, di-halo, halogene T30, HarvestCide, nylate, photobrome, slimicide 78P
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.004.334 Edit this at Wikidata
EC Number
  • 204-766-9
UNII
  • InChI=1S/C5H6BrClN2O2/c1-5(2)3(10)8(6)4(11)9(5)7/h1-2H3 checkY
    Key: PQRDTUFVDILINV-UHFFFAOYSA-N checkY
  • InChI=1/C5H6BrClN2O2/c1-5(2)3(10)8(6)4(11)9(5)7/h1-2H3
    Key: PQRDTUFVDILINV-UHFFFAOYAT
  • O=C1N(Br)C(=O)N(Cl)C1(C)C
Properties
C5H6BrClN2O2
Molar mass 241.47 g/mol
Appearance White solid
Density 1.9 g/cm3
Melting point 159 to 163 °C (318 to 325 °F; 432 to 436 K)
0.15 g/100 ml (25 °C)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Flamability, Inhalation
GHS labelling:
GHS03: OxidizingGHS05: CorrosiveGHS07: Exclamation markGHS09: Environmental hazard
Danger
H272, H302, H312, H314, H317, H332, H400
P210, P220, P221, P260, P261, P264, P270, P271, P272, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P333+P313, P363, P370+P378, P391, 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 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
1
1
Flash point Decomposes at 160°C
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

BCDMH is an excellent source of both chlorine and bromine as it reacts slowly with water releasing hypochlorous acid and hypobromous acid. It used as a chemical disinfectant for recreational water sanitation and drinking water purification.[1] BCDMH works in the following manner:[2]

The initial BCDMH reacts with water (R = Dimethylhydantoin):

BrClR + 2 H2O → HOBr + HOCl + RH2

Hypobromous acid partially dissociates in water:

HOBr → H+ + OBr

Hypobromous acid oxidizes the substrate, itself being reduced to bromide:

HOBr + Live pathogens → Br + Dead pathogens

The bromide ions are oxidized with the hypochlorous acid that was formed from the initial BCDMH:

Br + HOCl → HOBr + Cl

This produces more hypobromous acid; the hypochlorous acid itself act directly as a disinfectant in the process.

Preparation

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This compound is prepared by first brominating, then chlorinating 5,5-dimethylhydantoin:[3]

 

References

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  1. ^ NSF International (2012). "NSF/ANSI 60 - Drinking Water Treatment Chemicals - Health Effects". NSF Product and Service Listings. NSF International. Retrieved November 14, 2018. Bromochlorodimethylhydantoin[CL] - Bromicide Tablets - Algicide - Disinfection & Oxidation. [CL] The residual levels of chlorine (hypochlorite ion and hypochlorous acid), chlorine dioxide, chlorate ion, monochloramine and disinfection by-products shall be monitored in the finished drinking water to ensure compliance to all applicable regulations.
  2. ^ South Australian Health Commission, "Standard for the Operation of Swimming Pools and Spa Pools in South Australia", Supplement C: Bromine Disinfection Archived 2009-05-21 at the Library of Congress Web Archives, page 8. Retrieved on 2009-05-12.
  3. ^ Yasukazu Ura, Gozyo Sakata. "Chloroamines". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a06_553. ISBN 978-3527306732.
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