Effect of refractive index on molecular radiative lifetimes

✍ Scribed by John Olmsted III

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 646 KB
• Volume: 38
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(76)85156-1

✦ Synopsis

Reccivcd 27 October 1975 1%~ cffcct of the rcfractivc index of the medium (PI) on the fundamental photophysical par~rnetcrs 'R = l/lifhas been investi!:atcd, using the Ili~hly-tluoresccnt compound 9,10_cIiphcnq_lantl~r~ccnc (DPA). Experiments show that for DPA in iropcntanc solution. reducing the tcmpcmtllrc from room tcmpemfurc to -160°C (whcrcupon II increases from 1.35 1 to 1.439) causes the cxpcrimental fiuorcsccncc lifetime to dccrcasc from 8.8 tv 7.5 ns. l'hcsc: data and behavior of the intearratcd cxtinctinn coefficient arc consistent with iin /z-' to II-3 D dcpcndcnce of the radiative lifctimc. iiadiativc lifctimcs for the tbcrmalized gas phase are compared with those in solution for nnphthalenc an:1 pyrcnc and are also consistent with an 11~~ to 1zW3 dcpcndencc of the radiative lifctirnc. It is concluded that extrapolations of lifctimcs data from one set of conditions to another should not bc made unless absorption and/or quantum yield data are known under both conditions. When these data arc not available, un II-* correction factor applied to rR probably iS accurate to within ten percent.