De Luca Giovanna, Romeo Andrea, Scolaro Luigi Monsù
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone 31, 98166 Vill. S. Agata, Messina, Italy.
J Phys Chem B. 2006 Apr 13;110(14):7309-15. doi: 10.1021/jp0530348.
The tetrabutylammonium salt of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) is soluble in dichloromethane, and the general properties of this compound have been investigated as function of various added acids HX (X = Cl, Br, I, CF(3)COO, CF(3)SO(3), TFPB) through UV-vis absorption spectroscopy, steady state fluorescence emission, and resonance light-scattering (RLS) techniques. Upon addition of HX, the initial monomeric free base TPPS is readily converted in an aggregated species, whose spectroscopic features are independent of the nature of the counteranion X. All the spectroscopic evidence suggest a J-type arrangement of chromophores in this aggregate, involving strong hydrogen bonds, electrostatic, and dispersive interactions. In the specific case of chloride and bromide, in the presence of a TBAX excess, the addition of the corresponding acid leads to a monomeric ion-pair between the TBA cations and the diacid TPPS, whose central core is strongly interacting with the halide. On further increasing the acid concentration in these latter solutions, fully protonated species are formed that eventually start to aggregate.
5,10,15,20-四（4-磺酸基苯基）卟啉（TPPS）的四丁基铵盐可溶于二氯甲烷，通过紫外可见吸收光谱、稳态荧光发射和共振光散射（RLS）技术，研究了该化合物在添加各种酸HX（X = Cl、Br、I、CF(3)COO、CF(3)SO(3)、TFPB）时的一般性质。加入HX后，初始的单体游离碱TPPS很容易转化为聚集态，其光谱特征与抗衡阴离子X的性质无关。所有光谱证据表明，该聚集体中发色团呈J型排列，涉及强氢键、静电和色散相互作用。在氯化物和溴化物的特定情况下，在过量TBAX存在下，加入相应的酸会导致TBA阳离子与二酸TPPS之间形成单体离子对，其中心核与卤化物强烈相互作用。在这些溶液中进一步增加酸浓度时，会形成完全质子化的物种，最终开始聚集。
