Registration Dossier
Registration Dossier
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EC number: 815-305-1 | CAS number: 138938-64-4
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
Dissociation constant [1-(tert-butyldimethylsilyl)piperazine]: Not relevant due to very rapid hydrolysis
Dissociation constant [piperazine]: pKa1 = 9.73 and pKa2 = 5.33
Key value for chemical safety assessment
Additional information
The requirement to conduct a dissociation constant study for the submission substance is waived because in contact with water, it hydrolyses very rapidly to form tert-butyldimethylsilanol and piperazine.
The silanol hydrolysis product is not expected to dissociate within relevant pH associated with environmental assessment.
Piperazine has reported pKa1 = 9.73 and pKa2 = 5.33 (Perrin DD 1972).
Reference:
Perrin DD (1972). Dissociation Constants of Organic Bases in Aqueous Solution. IUPAC Chemical Data Series: Supplement. Buttersworth, London
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