This project aims to prepare a document describing guidelines for accurate measurements of luminescence spectra and quantum yields of metal complexes, inorganic compounds and materials. The document will disseminate basic knowledge, rules and protocols, not only to experts, but also to those new to this field.
Many fields of basic and applied chemistry, as well as material- and biosciences, employ luminescent inorganic compounds and materials, and the number of researchers, who are synthetic chemists but carry out photophysical measurements, is continually increasing. While some experimental procedures have been published, there remains a need for standardized protocols, especially for quantitative measurements for such materials. Once accepted as standards, these will provide guidelines for such measurements and they can be available to all researchers, regardless of their previous experience in photophysics or theoretical chemistry, thereby allowing for objective comparisons of results generated in different laboratories.
The IUPAC Organic Chemistry Division Commission on Photochemistry published “Reference Materials for Fluorescence Measurement”, D. F. Eaton, Pure Appl. Chem., 1988, 60, 1107-1114 (doi:10.1351/pac198860071107). This covers basic knowledge in fluorescence spectroscopy and quantum yield determination. However, there are some problems specific to inorganic compounds, which are not usually fluorescent but phosphorescent. Phosphorescence is generally air-sensitive and emits at longer wavelengths. It may be temperature dependent. Therefore, the experiments require additional attention. For instance, the correction function for the spectrometer is generally difficult to establish in the near-infrared (NIR) range. Detectors such as CCD cameras are more and more replacing the classical photomultiplier tube and reliable response curves are needed. Moreover, a major point in these experiments is the availability of highly reliable standards for relative emission quantum yield measurements.
Recently, some quantum yields of luminescent organic and inorganic compounds in solution have been reevaluated (Kengo Suzuki, et al., Phys. Chem. Chem. Phys., 2009, 11, 9850; doi:10.1039/b912178a). The emission quantum yield of ruthenium tris(bipyridine) complex, which is internationally used as a reference, has now been reevaluated to have a significantly higher value than previously reported.
All these reasons speak in favor of establishing new guidelines for the measurement of luminescence spectra and quantum yields of inorganic compounds and metal complexes. The document should describe a precise methodology for establishing the correction function, particularly in the NIR, as well as propose adequate standards for quantum yield determination of both highly and poorly luminescent inorganic compounds and complexes. It is foreseen that it will become an inspiring and enlightening pamphlet for chemists and material scientists who join the fast developing field of photochemistry and photophysics.
July 2010 – project announcement published in Chem. Int. Jul-Aug, p. 21
Sep 2016 update – A IUPAC Technical Report entitled “Guidelines for measurement of luminescence spectra and quantum yields of inorganic and organometallic compounds in solution and solid state: has been published in Pure and Applied Chemistry, Volume 88, Issue 7, Pages 701–711, DOI: 10.1515/pac-2014-0706.
The task group is planning a workshop to be held during the 97th Annual Meeting Chemical Society of Japan (CSJ), on Sunday, 19 March 2017, titled Frontiers of Development of Luminescent Materials Supported by Recent Technologies in Emission Measurements (Recent Technologies in Luminescence Measurements)
Program (updated Jan 2017)
Chairperson: Ken Sakai
13:30-13:55 Opening remark: background of the IUPAC project for publishing the guidelines for luminescence measurements (Kitasato University) Hitoshi Ishida
Chairperson: Koichi Nozaki
13:55-14:30 Avoiding common pitfalls in luminescence spectroscopy (Durham University, UK) Andrew Beeby
Chairperson: Miki Hasegawa
14:30-15:05 Evaluation of circularly polarized luminescence from lanthanide complexes and application to chiral sensing system (Univ. of Toyama) Munetaka Iwamura
Chairperson: Kengo Suzuki
15:05-15:30 Absolute emission quantum yield of singlet molecular oxygen in solution determined using an integrating sphere instrument (Gunma University) Seiji Tobita
Chairperson: Masako Kato
15:30-15:55 Fluorescence quantum yield measurements in highly purified organic crystals (Nihon University) Ryuzi Katoh
Chairperson: Kazuyuki Ishii
15:55-16:20 Estimation of the emission quantum yield for luminescent lanthanide materials (Hokkaido University) Yasuchika Hasegawa
16:20-16:30 Closing remark (Kyushu University) Ken Sakai
Page last updated: 26 April 2017