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Raman spectroscopic evidence shows that chloromethyl mercuric nitrate, ClCH2 HgONO2 (like methyl mercuric nitrate), is only partially dissociated into ions in aqueous solution. The percentage degree of dissociation in a nearly saturated solution (0.078 M) at 25°C, as determined by intensity measurements on the v1 Raman line of the nitrate ion, is found to be approximately 83 ± 7. This corresponds to a value of the dissociation constant Kc near 0.3 moles per liter. Thus the effect of introducing a Cl atom into the methyl group of CH3HgONO2 is to reduce Kc by a factor of about 100. This is in the opposite sense from the effect of a similar substitution in the case of acetic acid CH3COOH, which is to increase the acid dissociation constant Kc by a factor of about 100. These effects can be qualitatively understood in terms of the inductive effects of the Cl atom.

The pure rotational and rotation-vibrational Raman spectra of HCN and DCN have been photographed using a previously described instrument [7]. The molecular constants derived for HCN are in excellent agreement with those obtained from microwave and infrared spectroscopy. Especially, the measurements of the v1 rotation-vibrational Raman band have confirmed the hitherto indirectly obtained values for the molecular constants of the v1 vibrational state of HCN.

The vibrational Raman spectra of single fibres of Nomex and Kevlar have been studied and vibrational assignments made. Commercial samples of Kevlar 29 and Kevlar 49 were found to be identical spectroscopically. Distinguishing features in the Raman spectra of Kevlar and of Nomex were identified for the purpose of spectroscopic or microprobe characterisation of these materials as single fibres or as small particles (∼ 2 μm). The Raman spectra of Kevlar and Nomex fibres which had been subjected to mechanical stresses of up to 4.5 kg mm−2 were also analysed and comparisons made with previous results on stressing experiments in the literature for Kevlar.

The Raman and i.r. spectra of [Ni(CO)3(SbCl3)] are reported for the first time. A complete vibrational assignment is made, consistent with C3v molecular symmetry. The wavenumber of the nickel–antimony stretching vibration is ca. 230 cm–1.

Fourier Transform (FT) Raman spectra were obtained from 10 fossil resin specimens differing in localities, precise paleoecological situation and geological age. The series investigated includes amber from Moravia and Bohemia designated by local names: valchovite, retinite, neudorfite, schauffite and muckite. All fossil resins originate from freshwater deposits of Cenomanian age (Mesozoic). Non-altered amber from Jantarnaja (Baltic Russia), highly matured amber, rumanite and simetite and also přilepite of Westphalian age (Carboniferous) were investigated for comparison material. The FT-Raman spectra indicates the similarity between Bohemian and Moravian fossil resins and Baltic (Eocene) and Lebanon (Cretaceous) ambers. Important differences exist among the FT-Raman spectra obtained. Similarities between spectra of fossil resins of different ages, and differences between similar materials sampled at close localities, suggest the importance of the post-depositional conditions and alteration on the character of the resulting fossil resin. Copyright © 2004 John Wiley & Sons, Ltd.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:53Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:40:06Z : No. of bitstreams: 1 2-s2.0-33744719713.pdf: 617207 bytes, checksum: 103e0d8eb04a008b697bd29e4862fbed (MD5) Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:53Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:40:06Z : No. of bitstreams: 1 2-s2.0-33744719713.pdf: 617207 bytes, checksum: 103e0d8eb04a008b697bd29e4862fbed (MD5) Made available in DSpace on 2014-05-27T11:21:53Z (GMT). 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No. of bitstreams: 0 Previous issue date: 2006-06-08 Hybrid planar waveguides were prepared from Ti4+-acetylacetone (acac)-Ureasil sols deposited on glass substrates. Structural features have been investigated by spectroscopic measurements (Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Raman scattering) and Small Angle X-ray Scattering (SAXS). Addition of Ti 4+-acac to the ureasil (Ti:Si molar ratio 1:1) leads to the formation of bonds between the Ti complex and the siloxane groups, whereas further addition of Ti4+ (Ti:Si molar ratio 5:1) leads to the additional formation of titanium-rich nanoclusters. The optical parameters of the waveguides such as refractive index, thickness, propagating modes and attenuation coefficient were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique. The refractive index can be tuned by the Ti4+ relative content. The few microns thick planar waveguides support well confined propagating modes with low attenuation loss for all compositions. ©2006 Sociedade Brasileira de Química. Instituto de Química Universidade Estadual Paulista, CP 355, 14801- 970 Araraquara - SP Departamento de Química Universidade de Trás-os-Montes e Alto Douro, 5001 Vila Real Codex Departamento de Física Universidade de Aveiro, 3810 Aveiro CNR-INF Instituto di Fotonica I Nanotecnologie CSMFO Group, via Sommarive 14, 38050, Povo (TN) IDipartimento di Fisica Università di Trento CSMFO Group, via Sommarive 14, 38050 Povo, (TN) Departamento de Química Universidade de São Paulo, 14040-901 Ribeirão Preto - SP Departamento de Quimica Universidade Federal de Juiz de Fora, 36036-900 Juiz de Fora - MG Department of Chemical and Forensic Sciences University of Bradford, Bradford, BD7 1 DP Instituto de Química Universidade Estadual Paulista, CP 355, 14801- 970 Araraquara - SP

inlaid porcelain plaques prior to its restoration and compared with the body and glaze of a damaged, marked porcelain plate from the Rockingham factory. The spectra are consistent with the two specimens having the same manufacturing source around 1840. The analysis of the body of the plate and the plaque fragment shows that both contain b-wollastonite, feldspar and calcium orthophosphate; in addition, a trace of gypsum was found on the bottom surface of the plaque fragment, indicating that plaster was used as an adhesive and bedding agent for the plaques on their wooden table-top substrate. The porcelain bodies of the plaque and the plate are classified as English soft-paste porcelain with bone-ash additive and differences in the spectra can be ascribed to changes in the firing temperature and kiln cycles. The glaze compositions are also very similar with the identification of borax in each specimen. It is concluded analytically that the porcelain plaques were derived from the Rockingham factory around 1835‐40, which can be correlated with historical provenancing. Copyright  2004 John Wiley & Sons, Ltd.

The Raman and i.r. spectra of [Ni(CO)3(SbCl3)] are reported for the first time. A complete vibrational assignment is made, consistent with C3v molecular symmetry. The wavenumber of the nickel–antimony stretching vibration is ca. 230 cm–1.