title: The electronic spectra of porphyrin-like cobalt-tetracarboxy-phthalocyanines as modified by polylysine and polyglycols.
abstract: The effect of poly-L-lysine and polyglycols on the electronic spectral properties of cobalt-tetracarboxy-phthalocyanine, compound (I), was studied in order to determine the effect of the polymers on the molecular stacking properties of compound (I). In the present study we have coupled, both covalently and electrostatically, the poly-L-lysine to compound (I). The electrostatic interaction with the polylysine resulted in a bathochromic shift of absorbance by compound (I) from 680 to 695 nm, and the generation of shoulders in the 590 and 580 nm region. The bathochromic shift indicates that the polylysine either misaligns the units of compound (I) in the molecular stack or alters the angular relationship of the planar compound (I) molecules. The covalent linkage with the polylysine resulted in stabilization of the monomeric form of compound (I) with no hypochromism in the 680 nm region. The reaction of the polyglycols, dextran and DEAE dextran with compound (I) prior to the addition of the polylysine, stabilized the polymeric stacked form of compound (I) in the presence of the polylysine. Ammonium ion and ethanolamine resulted in the appearance of peaks in the 730-760 nm region; a trihydroxy containing primary amine and monomeric lysine generated no such peak at wavelengths above 700 nm. The polyglycol binding capacity of compound (I) facilitated the separation of the unbound compound (I) from the polymeric complexes.
mesh_terms: D004396:Coloring Agents; D007211:Indoles; D009942:Organometallic Compounds; D011100:Polyglycolic Acid; D011107:Polylysine; D013053:Spectrophotometry
chemical_list: D004396:Coloring Agents; D007211:Indoles; D009942:Organometallic Compounds; D011107:Polylysine; D011100:Polyglycolic Acid; C052178:cobalt tetracarboxyphthalocyanine