四(β-N-乙酸甲酯)吡啶基卟啉和四(β-N-氰乙基)吡啶基卟啉在水溶液中的酸碱平衡

ACID-BASE EQUILIBRIA OF TETRAKIS (β-N-ACETATEMETHYL) PYRIDYLPORPHYRIN AND TETRAKIS (β-N-ETHYLNITRILE) PYRIDYLPORPHYRIN IN WATER SOLUTION

本文报道了在25±0.1℃,0.5mol·1^(-1)KCl介质中,水溶性的溴化四(β-N-乙酸甲酯)吡啶基卟啉(H_2T_(β-N-ACMS) PyPBr_4)和溴化四(β-N-氰乙基)吡啶基卟啉(H_2T_(β-N-ECN)PyPBr_4)的酸碱平衡。并求得H_2T_(β-N-ACMS)PyP的pK_(a_3.4)=3.81±0.20,pK_(a_2)=6.39±0.03,pK_(a_1)=13.84±0.08;H_2T_(β-N-BCN)PyP的pK_(a_3.4)=3.70±0.20,pK/a_2=6.09±0.04.

The acid-base equilibria of water soluble tetrakis(β-N-acetatemethyl) pyridylporphyrin (H2Tβ-N-ACMSPyP) and tetrakis(β-N-ethylnitrile)pyridylporpyhrin were studied by spectrophotometric titration in 0.5mol·l-1KCl solution at 25.0+0.1℃. Thevalues of pKa's are, pKa3,4=3.81 ±0.20, pKa2 =6.39±0.03, pKa = 13.84±0.08, for H2Tβ-N-ACMSPyPp, Ka3,4=3.71±0.20, PKa2=6.092±0.04, for H2Tβ-N-ECNPyP.