Calcein, Fluorescein Complexon

Cadion, [l-(4-nitrophenyl)-3-(4-phenylazophenyl)-triazene] Calcein, Fluorescein Complexon Calcium hydride, in purification Carbon Black... 

Other Names Fluorescein, 2, 7 - w[[ (carboxymethyl)amino]melliyl]- Spiro[isobenzofuran-l (3H),9 -[9Fl]xantliene], glycine derivative 2,7-fi [iV,lV-to(carboxymethyl)aminomethylene]-fluorescein Acetic acid, [(3, 6 -dihydroxy-2, 7 -fluorandiyl)fci>(methylenenitrilo)]telra- Calcein Fluorescein complexon Fluorexon NSC 298193 Oftasceine CA Index Name Glycine, A7V -[(3, 6 -dihydroxy-3-oxospiro[isobenzofiiran-l(3II),9 -[9ir xanthene]-2, 7 -diyl) M(methylene)] is[N-(carboxymethyl)-CAS Registry Number 1461-15-0 Merck Index Number Not listed Chemical Structure... 

Calcein (Fluorexone, Fluorescein Complexone) (formula 4.22), used as reagent for the determination of calcium, contains iminodiacetic acid groups in positions 2 and 7, and only one hydroxyl group in position 3. In the case of Calcein (like Xylenol Orange), the nitrogen atom of the iminodiacetic acid group participates in bonding the metal ion. 

Calcein sodium salt [2, 7 -bis- V,V-di(carhoxymethyl)aminomethyl fluorescein Na salt, Fluorexon, Fluorescein Complexon] [108750-13-6 diNa salt, 1461-15-0 free acid] M 666.5, pKEst(i) 1-9, pKesi<2) 2.5, pKEst(3) 8,0, pKesK4) 10.5 (all for N-CH2COOH), and pKes s) ... 

With calcein (a derivative of fluoresceine), the titration is very sensitive. Titrations with complexone(III) solutions of concentrations of about 10 mol/L can be carried out. At the endpoint, the yellow-green fluorescence disappears, whereas a violet color appears quasi-simultaneously. 

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