Raman and infrared spectra of transition metal halide hexahydrates

Abstract

The Raman and infrared spectra of NiC12.6H20, NiC1,-6Dz0, CoCl,.6H,O, CoC1,-6Dz0 and CoBr,-6H,O single crystals have been measured in the range 3600-30 cm-' (Raman) and 3800-400 cm-' (IR). The water internal modes have been best assigned for NiC12.6H,0, including Fermi resonance effects. The corresponding Raman intensities have been interpreted in terms of the free molecule Raman tensors. Among the lattice vibrations, the metal halide and metal-water stretchings, and also the librations of the MX2.4H20 octahedra, have been identified and assigned.

Raman studies of NiX2 · 6H2O and FeCl2 · 4H2O

“…The attribution is different from that given in Ref. 1 and is made using the results in Ref. 9, which indicate that a lowering in the v2 bending frequency is due to the cation-water coordination, an effect which is absent in the lattice water situation.…”

Theoretical and experimental investigation of nickel isotopic fractionation in species relevant to modern and ancient oceans

“…The structure of NiCl 2 (H 2 O) 4 can be in cis-and trans-geometries (Mizuno, 1961;Kleinberg, 1969;Agulló -Rueda et al, 1987;Waizumi et al, 1992b;Ptasiewicz-Bak et al, 1999). Structural studies on NiCl 2 (H 2 O) 4 crystals indicated that cisNiCl 2 (H 2 O) 4 was the dominant species (Waizumi et al, 1992b;Ptasiewicz-Bak et al, 1999), while other studies found that trans-NiCl 2 (H 2 O) 4 was dominant (Mizuno, 1961;Kleinberg, 1969;Agulló -Rueda et al, 1987). Therefore, the geometries of both cis-and trans-NiCl 2 (H 2 O) 4 species were calculated.…”

Synthesis of NiF2 and NiF2·4H2O Nanoparticles by Microemulsion and Their Self-Assembly

“…The peaks at 431 and 308 cm –1 correspond to the A 1g and E g vibration modes of NiF 2 . The rest of the peaks are due to the different vibration modes of the Ni–O bond and H 2 O and the symmetric stretching mode of hydrogen bond. , …”

“…The peaks at 431 cm -1 and 308 cm -1 corresponds to A 1g and E g vibration modes of NiF 2 , respectively 63 . The rest of the peaks are due to the different vibration modes of Ni -O bond and H 2 O, and symmetric stretching mode of hydrogen bond [64][65] . (i) irregular shaped particles spread over a wide range of size SEM images of samples "1" to "3" and "4" to "6" are presented in Figure 2 and Figure 3, respectively.…”

“…63 The rest of the peaks are due to the different vibration modes of the Ni−O bond and H 2 O and the symmetric stretching mode of hydrogen bond. 64,65 The SEM images of samples 1−3 and 4−6 are presented in Figures 2 and 3, respectively. The SEM images of sample 1 (ω = 16.18, α < 1, and reaction time of 15 min) show predominant and larger structures having almond-like shapes and less frequent and smaller truncated bipyramidal structures (Figure 2a,b).…”