The XPS Fe 2p3/2 core-level spectra of sodium hexacyanoferrate(ii) and sodium nitroprusside.

Core-shell CdSe/ZnS quantum dots are promising as bio-luminescent markers: being conjugated to bio molecules (proteins), they serve as luminescence tags in antigen-antibody biochemical reaction. This presents a possibility to detect, for example, the variation of the protein biomarkers to promote the early cancer diagnosis. We studied the effect of bio molecules conjugated to QDs using Raman scattering spectra, and found that in some cases the conjugation leads to noticeable variation of these spectra, so that the detection of bio molecules could be done more accurately. An explanation of the effect is proposed.

This study reports an evaluation on the scope of X‐ray photoelectron spectroscopy (XPS) to obtain information for the coordination chemistry of transition metal (Tn) hexacyanometallates, TxAz[Mm(CN)6]y where nx +z = y(6 – m), A is an alkaline charge‐compensating cation, and Mm is a transition metal with a maximum of 6 electrons in its nd orbitals. XPS provides an elegant picture on the role of the CN π‐back bonding effect to determine the charge density on the N atom and, from this fact, on its coordination to transition metal ions to form coordination polymers. XPS appears to be able to discriminate between octahedral and tetrahedral coordination for the outer metal (T) to the N end of CN ligands, particularly when the XPS peak and the Auger lines are combined. A similar performance was observed when this spectroscopic technique is used to identify when the CN ligand is found with linear and bifurcated coordination mode to the metal linked at its N end. These last two structural features are relevant in the coordination of metal hexacyanometallates and determine their physical and functional properties. The results obtained from XPS data were correlated with the a priori information from IR spectra and the reported crystal structures for all the samples under study.

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