Diagnostic probes

Plenary 18. Robin J FI Clark, e-mail address r.i.h.clark ucl.ac.uk (RS). Reports on recent diagnostic probing of art works ranging from illuminated manuscripts, paintings and pottery to papyri and icons. Nondestructive NIR microscopic RS is now realistic using CCD detection. Optimistic about new developments. 

Grenier, E., Bonifassi, E., Abad, P. and Laumond, C. (1996) Use of species-specific satellite DNAs as diagnostic probes in the identification of Steinernematidae and Heterorhabditidae entomopathogenic nematodes. Parasitology 113, 483-489. 

The pressure dependence of the thermal variation of has proved to be a useful diagnostic probe to show that the formation of [HS-LS] spin pairs is not fortuitous but that they are the preferentially formed species in the dinuclear-type complexes [9]. It is shown next that application of external hydrostatic pressure can help to unravel features of this whole class of compounds, which usually can be revealed by variation of chemical composition. 

Formyl complexes are characterized by distinct spectroscopic features. The most frequently used diagnostic probe has been H NMR. Chemical shifts in the 8 12-17 range (several ppm downfield from normal aldehyde or formamide H-NMR resonances) (69) are observed. However, since chemical shifts measured in the presence of trialkylborane by-products can show marked temperature dependence (32, 38, 47, 66), absolute values must be treated with caution. 

Two techniques, which appear well suited to the diagnostic probing of practical flames with good spatial and temporal resolution, are coherent anti-Stokes Raman spectroscopy (CARS) and saturated laser fluorescence. The two techniques are complementary in regard to their measurement capabilities. CARS appears most appropriate for thermometry and major species concentration measurements, saturated laser fluorescence to trace radical concentrations. With electronic resonant enhancement (6), CARS may be potentially useful for the latter as well. Fluorescence thermometry is also possible (7, 8) but generally, is more tedious to use than CARS. In this paper, recent research investi-... 

Clearly, this proposed congestion at the critical branched state M, should exhibit (1) sterically-inhibited reaction rates, (2) sterically-induced stoichiometry, and, quite possibly, (3) a critical phase change due to surface cooperativity (association). These phenomena have been observed experimentally for the Starburst PAMAM dendrimers and may prove to be diagnostic probes for this critical branched state in other dendrimer families. 

Sappa et al. in their review (17). This constitutes quite a powerful diagnostic probe for such complexes. The reason for the appearance of this signal at such a low field may be due to the fact that the proton is bonded to a carbon which is partially carbenic in character. 

We shall also use element effects (Table 25) and p-valucs (Table 26) as diagnostic probes for mechanism. Here, too, we have compiled data for other organic series so that comparisons can be made between these systems and haloalkynes. More specific use of the data in Tables 24-26 together with regioselectivity material in Section Il.C.l.d and Table 6 will be made in the following section. 

Adam W, Bronstein I, Trofimov AV, VasiTev RE. Solvent-cage effect (viscosity dependence) as a diagnostic probe for the mechanism of the intramolecular chemically initiated electron-exchange luminescence (CIEEL) triggered from a spiroadamantyl-substituted dioxetane. J Am Chem Soc 1999 121 958-61. 

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