Pheophorbide-a and b methyl esters, as initial degraded products from chlorophyll-a and b, were used as starting materials, and the hydroxylmethylic or formylic structures were established making use of the active reaction regions on chlorin periphery by some common reactions, such as aldol condensation, allomerization, oxidant oxidation. The methylene or vinyl groups possessing higher reactivity were introduced at different site around chlorin pericycle by Grignard reavtion, acid-catalyzed dehydration and rearrangement reaction in E-ring. A series of unreported chlorophyllous chlorins substituted by multi-terminal alkenyl group were synthesized and their chemical structures were characterized by elemental analysis, UV, IR and 1 H NMR spectra. The in vitro photosensitive bactericidal activities of new chlorins were discussed and the possible mechanisms about corresponding reactions were tentatively proposed.

As a continuation of our previous study in which the basic data about the NH4Cl–CaCO3–H2O ternary system was measured, the solubility and physical properties (density, viscosity, and refractive index) of calcium carbonate in ammonium sulfate aqueous solution at (298.15, 323.15, and 348.15) K have been investigated by using the isothermal dissolution method in this work. The results showed that the solubility of calcium carbonate increased as the molality of ammonium sulfate aqueous solutions and temperature increased. The solubility of calcium carbonate in ammonium sulfate aqueous solutions and the viscosity of aqueous solutions were correlated with the second-order polynomial equation and semiempirical exponential model equation, respectively. By comparing the calculated values with experimental data, the second-order polynomial equation and semiempirical exponential model equation provide accurate mathematical representations of the experimental results. The obtained experimental data in this work could provide available data for the industrial production of calcium carbonate products and further theoretical studies.