An algorithm to remove cosmic ray (CR) features from Raman spectra collected in mapping experiments using a charge-coupled device (CCD) is presented. Each spectrum is compared to spectra collected from adjacent points in space using correlation values. The most similar neighbor (MSN) spectrum is selected, offset, and used for identification of CRs. The offset values are defined in terms of the noise level for data with a low signal-to-noise ratio and in terms of the peak height for data with a high signal-to-noise ratio. Scaled intensity values of the MSN spectra are used for replacement of contaminated pixels, allowing for full recovery of underlying spectral features. The algorithm is applicable for any Raman map where the particle sizes within the analyzed mixture are larger than the sampling size or to any other data where the sampling is more frequent than the variation, e.g., time series or temperature profiles. Its application to several maps of pharmaceutical samples is discussed here. With an appropriate offset value for the MSN spectra, no misdetections occur, and all CRs more intense than the offset are removed, which includes the CRs that would have hampered subsequent chemometric analysis by methods such as principal component analysis (PCA).

The reaction between equimolar quantities of BiCl3 and the silylphosphine P(SiMe3)3 in toluene or THF (tetrahydrofuran) solution affords a black precipitate with the composition of bismuth phosphide, BiP, which has been examined by EDXA, SEM, XPS, powder XRD, solid-state 31P NMR spectroscopy, and elemental analysis. Alternative possible routes to BiP involving the reactions between Na3P and BiCl3 and between Bi(NMe2)3 and P(SiMe3)3 have also been investigated, both of which afford black powders of composition close to BiP, although in the latter case there is some contamination with bismuth metal. Analogous reactions with either SbCl3 or AsCl3 and P(SiMe3)3 afford black and dark brown precipitates, respectively, which are formulated as the materials antimony phosphide, SbP, and arsenic phosphide, AsP, on the basis of similar analyses. Preliminary experiments have also shown that the related arsenides, BiAs and SbAs, can be prepared from reactions between either BiCl3 or SbCl3 and the silylarsine As(SiMe3)3, and that a ternary phase with the composition BiSbP2 is formed in the reaction between BiCl3, SbCl3, and P(SiMe3)3 in a 1:1:2 mole ratio. A material of composition close to elemental phosphorus is obtained from the reaction between PCl3 and P(SiMe3)3.

Preparation and Characterization of a Material of Composition BiP ( Bismuth Phosphide) and Other Intergroup 15 Element Phases. -The black precipitate formed in 85% yield by reaction of equimolar amounts of BiCl3 and P(SiMe3)3 (I) in toluene or THF is consistent with BiP as shown by EDXA, SEM, XPS, powder XRD, solid-state 31P NMR spectroscopy and elemental analysis. A black solid assumed to be BiP contaminated with some Bi is also obtained in 93% yield from (I) and Bi (NMe2)3 in toluene. Analogous reactions of SbCl3 or AsCl3 with (I) yield SbP and AsP, respectively. By reaction of BiCl3, SbCl3, and (I) in 1:1:2 molar ratio BiSbP2 is formed in 90% yield. Reaction of an equimolar mixture of PCl3 and (I) in toluene yields an orange solid of Px. -(ALLEN, G. C.; CARMALT, C. J.; COWLEY, A. H.; HECTOR, A. L.; KAMEPALLI, S.; LAWSON, Y. G.; NORMAN, N. C.; PARKIN, I. P.; PICKARD, L. K.; Chem.