{"corpus_id":94603397,"paper_sha":"3b77483317c9c7deb0c88345cfc24470ba78b45a","doi":"10.1111/j.1751-1097.1995.tb08619.x","arxiv_id":null,"pmid":null,"pmcid":null,"mag_id":1981615802,"dblp_id":null,"acl_id":null,"title":"PHTHALOCYANINE FLUORESCENCE AT HIGH CONCENTRATION: DIMERS OR REABSORPTION EFFECT?","year":1995,"publication_date":"1995-04-01","venue":"","journal":{"name":"Photochemistry and Photobiology","pages":null,"volume":"61"},"journal_issn":null,"journal_title":null,"publication_types":[],"pubmed_pub_types":null,"s2_fields_of_study":["Chemistry"],"reference_count":28,"citation_count":191,"influential_citation_count":7,"is_open_access":false,"arxiv_categories":null,"arxiv_license":null,"arxiv_journal_ref":null,"mesh_headings":null,"chemicals":null,"comments_corrections":null,"source_flags":1,"s2_open_access_pdf_url":null,"s2_open_access_landing_url":null,"s2_open_access_license":null,"s2_open_access_status":null,"pmc_open_access_pdf_url":null,"pmc_open_access_landing_url":null,"pmc_open_access_license":null,"pmc_open_access_status":null,"unpaywall_open_access_pdf_url":null,"unpaywall_open_access_landing_url":null,"unpaywall_open_access_license":null,"unpaywall_open_access_status":null,"abstract":"Abstract— For tetrasulfonated aluminum phthalocyanine (AlPcS 4 ), dimer formation is characterized in the absorption spectrum by a broadening of the Q‐band and the appearance of a new band at the red edge of the spectrum. The high concentrations required to produce dimers, however, often leads to anomalous observations in fluorescence spectroscopy. In the present study, we have examined the photophysical characteristics of two dye systems; AlPcS 4 in a 66% ethanol/water mixture and disulfonated aluminum phthalocyanine in methanol. Using absorption spectroscopy, the formation of dimers is shown to be prevalent only in the case of AlPcS 4 . The fluorescence emission spectra in both cases, however, exhibit similar spectral changes with increasing dye concentration. The measured fluorescence decay profiles for both dyes also show similar trends: They are monoexponential, invariant with emission wavelength and have decay times that increase with dye concentration. These distortions are sometimes incorrectly attributed to dimer fluorescence. We find no evidence for the existence of dimer fluorescence and demonstrate that these data can be readily explained, by taking into consideration the effects of reabsorption of fluorescence.","claims":[{"public_id":"cl_f4e71e6ec5301a3b7b1139e20fa8526c","status":"active","text":"Dimer formation is prevalent in tetrasulfonated aluminum phthalocyanine in a 66% ethanol/water mixture, but not in disulfonated aluminum phthalocyanine in methanol.","confidence":0.97,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_f4e71e6ec5301a3b7b1139e20fa8526c"},{"public_id":"cl_46eeb75b93c6390e77ef087fc02df78d","status":"active","text":"Fluorescence decay profiles for both dyes are monoexponential, independent of emission wavelength, and their decay times increase with dye concentration.","confidence":0.96,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_46eeb75b93c6390e77ef087fc02df78d"},{"public_id":"cl_38b011e7761aee539b883b2827ca7da3","status":"active","text":"Fluorescence emission spectra for both dye systems change similarly as dye concentration increases.","confidence":0.92,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_38b011e7761aee539b883b2827ca7da3"},{"public_id":"cl_102f66248c6e9ae4690d008357cc8d01","status":"active","text":"There is no evidence for dimer fluorescence, and the observed spectral distortions are explained by fluorescence reabsorption.","confidence":0.98,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous 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