Shpol’skii matrices

Piakhotnik T, Moerner W E, Irngartinger T and Wild U P 1994 Single molecule spectroscopy in Shpol skii matrices Chimia 48 31-2... 

Two line narrowing techniques, matrix isolation and resonant laser excitation, are being used separately and in combination to eliminate inhomogeneous broadening (94). Microenvironmental inhomogeneities are reduced by freezing the sample into uniform site locations in isolation or Shpol skii matrices (95). Alternatively, with highly monochromatic and tunable lasers, it is possible to photoexcite only the subset of emitter sites in a low temperature matrix which have... 

Table 4. Emitting sites of Pd(2-thpy)2 in per-protonated and per-deuterated n-octane Shpol skii matrices at T = 1.3 K. Ccompiex= 10 mol 1. CooUng rate = 100 K/min [57]...

Table 6. Electronic origins of different sites of Pt(2-thpy)2 4.2 K) (from Ref. [59]) in several Shpol skii matrices (T = ...

Lamotte M, Rima J, Garrigues P, et al. 1985. Quantitative analysis of PAH (polynuclear aromatic hydrocarbons) in environmental samples by fluorometry in Shpol skii matrices at low temperature. Polynuclear Aromatic Hydrocarbons 785-798. 

A comprehensive review of hole burning spectroscopy of species in glasses has been prepared by Haarer and Silbey. Electric field effects on the spectral holes for perylene in Shpol skii matrices in n-heptane provide a useful extension of this technique . The limitations of the thermal lens method for the measurement of fluorescence yields have been examined and discussed . It is pointed out that the... 

Narrow ODMR signals are found in molecular crystals and in Shpol skii matrices in which they may be less than 1 MHz wide. On the other hand, ODMR signals that are observed in biological molecules dissolved in low-temperature aqueous glasses typically are about two orders of magnitude larger. The ODMR transitions are inhomogeneously broadened as a result of a distribution of solvent-molecule interactions, where the solvent ... 

An interesting recent example is the use of Shpol skii matrices to study ultrafast phenomena. The excited state proton transfer reaction in 3-hy-droxyflavone could be calculated from the (relatively) broad bands in the Shpol skii excitation spectrum, using the Heisenberg uncertainty principle. 

Very complex mixtures such as coal-derived materials often result in undesirably overlapping spectra for PAHs in Shpol skii matrices when a xenon lamp is used as the radiation source. In such cases, provided a sufficiently monochromatic source is used, the fluorescence may be selectively excited from one specific compound in a complex mixture of very similar PAHs. In practice, selective excitation usually entails using a laser for excitation. LIF in Shpol skii matrices has been used to identify and quantify individual PAHs in highly complex coal-derived materials. By way of example. Figure 2 shows the site-selective fluorescence of four individual PAHs in a solvent-retained coal liquid sample. The spectra were recorded following a 1000-fold dilution of the... 

SMS techniques is approximately 16. Work is in progress on new materials, such as other AHCs and additional Shpol skii matrices. It is to be expected that some laser dye molecules in appropriate hosts will also have the strong fluorescence, weak triplet bottlenecks, and near-absence of spectral hole-burning required for SMS studies. 

---