carbocyanines and phthalocyanine

Several classes of small organic molecules exhibit properties that make them suitable for fluorescence in vivo imaging. The most promising candidates are cyanines, squaraines, boron dipyrromethenes, porphyrin derivatives, hydroporphyrins, and phthalocyanines. The recent designing and synthetic efforts have been dedicated to improving their optical properties (shift the absorption and emission maxima toward longer wavelengths and increase the brightness) as well as increasing their stability and water solubility. The most notable advances include development of encapsulated cyanine dyes with increased stability and water solubility, squaraine rotaxanes with increased stability, long-wavelength-absorbing boron dipyrromethenes, long-wavelength-absorbing porphyrin and hydroporphyrin derivatives, and water-soluble phthalocyanines. Recent advances in luminescence and bioluminescence have made self-illuminating fluorophores available for in vivo applications. Development of new types of hydroporphyrin energy-transfer dyads gives the promise for further advances in in vivo multicolor imaging.

Topics: Carbocyanines; Fluorescent Dyes; Indoles; Isoindoles; Luminescence; Oxygen; Porphyrins; Solubility; Spectrometry, Fluorescence; Water

The tetra-sulfonated phathalocyanine cobalt(CoPcS4)was synthesized by using 4-sulfonic phthalic acid as raw material, CoCl2 as template agent and (NH4)2 MoO4 as catalyst. CoPcS4 was demonstrated to be C4h mono-isomer by elementary analysis, IR, NMR and HLPC. Depolymerization of CoPcS4 was found in DMSO. The depolymerization increased with the pH value raising. The interaction of tetra-sulfonated phathalocyanine cobalt with bovine serum albumin (BSA) was studied by UV-Vis and fluorescence spectra The number of binding sites and binding constant were determined at equal pace of the order of magnitude 10(5) L x mol(-1). CoPcS4 binds with BSA at Site I and Site II. In conclusion, COPcS4 binds with BSA commendably and albumin plays a role of storage and transport.

Topics: Animals; Carbocyanines; Cattle; Cobalt; Hydrogen-Ion Concentration; Indoles; Isoindoles; Serum Albumin, Bovine; Spectrometry, Fluorescence; Spectrophotometry

Tetraazaporphyrins (TAPs), phthalocyanines (Pcs), naphthalocyanines (Ncs), and anthracocyanines (Acs) with four tert-butyl groups attached at similar positions have been synthesized, and their electronic absorption, magnetic circular dichroism (MCD), IR, and voltammetric properties were studied and interpreted with the help of quantum-mechanical calculations. Through the preparation of a series of compounds with the same number of the same substituent, the effects of the increase in the size of the ring system were clearly derived. The main results may be summarized as follows. 1) The Q band shifts to longer wavelength and its intensity increases, but with decreasing degree of change with increasing molecular size. If the size of the effect of benzene directly fused to the TAP skeleton is set at unity, the effects of the second and third benzene units are roughly 0.8 and 0.5, respectively. 2) The splitting of the Q bands in metal-free compounds decreases with increasing molecular size, so that the Q bands of H2Nc and H2Ac appear as single bands. 3) The magnitude of the orbital angular momentum of the excited state of the ligand decreases with increasing molecular size. 4) Interestingly, the ring current, as judged from the positions of pyrrole proton signals in the 1H NMR spectrum, appears to decrease with increasing molecular size. 5) The first reduction potential becomes less negative, but only slightly, whereas the first oxidation potential shows a marked shift to less positive values with increasing molecular size, indicating that the HOMO destabilizes significantly as the molecule becomes larger. 6) In 5), the extent of the HOMO destabilization with molecular size differs depending on the central metal, so metals producing smaller destabilization effects can allow larger macrocycles. Of the metals studied, the most effective is cobalt, and the practical size limit is represented by the Acs. 7) The IR spectra become simpler the larger the molecule, and the main bands were assigned by DFT calculations. 8) The trend in experimentally determined redox potentials and electronic absorption and MCD spectra were reasonably reproduced by MO calculations using the ZINDO/S Hamiltonian. 9) EPR data for several metallocomplexes are also reported.

Topics: Carbocyanines; Electrochemistry; Indoles; Isoindoles; Models, Molecular; Protoporphyrins; Quantum Theory; Spectrophotometry, Infrared