A series of nickel N-methyl-pyridylethynylporphines were synthesized and their electrochemical and absorption properties were studied. UV-visible spectra of these complexes show that the absorption red-shifts of the nickel porphyrins are as significant as the zinc analogues. Although the reduction potential shifts caused by the electron-withdrawing substituents are not as large as the zinc complexes, the first reduction potentials of the nickel porphyrins are more positive than those of the zinc counterparts. In addition, the redox behaviors of these nickel porphyrins are similar to those of the zinc analogues.
Free-base, nickel(II), zinc(II) and iron(III) mono(4-aniline-ethynyl)biphenylporphines (AEBPPs) were synthesized and their electro-polymerization reactions were studied. Electrochemical and UV-Visible experiments showed that AEBPPs were electro-polymerized onto Pt and indium tin oxide (ITO) surfaces without significantly changing their redox and spectral properties. This suggests that the pi-conjugations of these porphyrins were not greatly affected upon electro-polymerization. SEM images indicated the formation of porphyrin films on the electrode surfaces, while EDS spectra of the metallo-AEBPP films confirmed deposits of the corresponding metals. Upon closer inspection, the AFM images revealed nano-scale fine structure of these porphyrin films. Both SEM and AFM images of the porphyrin films showed similar trends of porphyrin accumulation.
1,4-Di-4-pyridylpiperazine 1 was prepared from reaction of piperazine with 4-chloropyridine and then further blended with p-alkoxybenzoic acids. Subsequently, a series of H-bonded complexes were obtained and the mesogenic behaviours of the complexes were then investigated. A good quality of crystal from 1,4-di-4-pyridylpiperazine and p-octyloxybenzoic acid for single crystal structure determination was also isolated and then studied.Scheme I The preparation of compound 1 Fig. 1. (a; left) the texture of complex 2d at 208.5°C during the heating. (b; right) the texture of complex 2d at 189.5°C during the heating.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.