CAS 23897-16-7 appears in our catalog under these names: Dimesitylphosphine oxide 97%, Bis(2,4,6-trimethylphenyl)phosphine oxide, 98%, 98%, Bis(2,4,6-trimethylphenyl)phosphine oxide, 98%. Offered by: Ambeed, Chemat, Fluorochem. Available pack sizes: 1g, 5g, 25g, 100mg, 250mg, 10g.