Synthesis, electrochemical and spectroscopic investigations of 2,2′:4,4″-terpyridine and 2,2′:4,4″:6,2″-quaterpyridine ligands for metal complex photoelectrochemistry

The synthesis of 2,2′:4,4″:6,2′″-quaterpyridine and 2,2′:4,4″-terpyridine was accomplished by a reverse aldol condensation reaction of the appropriate aldehyde with alkyl and pyridyl acetyls. A selective quaternization method in toluene is described. In this method the 1,1′ nitrogens survive alkylation and are free to coordinate with metals to form metal complexes. The electrochemical behaviour of the neutral ligands as well as the monoquaternized cations was established by linear sweep cyclic voltammetry. Spectroelectrochemical techniques were used to establish the electronic spectral behaviour and stability of the radicals obtained upon reduction. Key words: 2,2′:4,4″-terpyridine, quaterpyridine, selective quaternization.

A spectrophotometric assay of Indulin C - A potential new substrate for determination of lignin-degrading abilities of microorganisms

A basic spectrophotometric study of a commercially produced sodium salt of Kraft lignin (Indulin C) was performed. The method of quantitative determination of Indulin C based on its absorbance at 276 nm has been found to be applicable. The spectra were also studied by means of derivative UV-spectrophotometry, which is recommended for theoretical studies of electronic spectral behaviour of lignins and lignin model compounds. Linear dependences were found between Indulin C concentration and the second derivative of spectrum at 250 nm and 276 nm. Both methods were used for determining the lignin degrading ability of the basidiomycete Phanerochaete chrysosporium and their suitability is discussed.