Infrared, Single Crystal Raman, and SERS Spectra of CH3NH3NaSeO4 · 6X2O and NaNH4SeO4 · 2X2O (X = H,D)

✍ Scribed by Daizy Philip; G. Aruldhas; T. Osaka; A. Miyazaki

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 277 KB
• Volume: 110
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1140

✦ Synopsis

IR and polarized Raman spectra of (\mathrm{CH}{3} \mathrm{NH}{3} \mathrm{NaSeO}{4} \cdot 6 \mathbf{H}{2} \mathrm{O}) (MASS), (\mathrm{NaNH}{4} \mathrm{ScO}{4} \cdot 2 \mathrm{H}{2} \mathrm{O}(\mathrm{SAS})), and their deuterated analogues are recorded and analyzed. In both the crystal symmetry of (\mathrm{SeO}{4}^{2-}) is lower than (T_{d}). The symmetry of (\mathrm{CH}{3} \mathrm{NH}{3}^{+})is lower than (\mathrm{C}{3 v}) and hydrogen bonding is strong in MASS. (\mathrm{NH}{4}^{+})is not rotating freely in the crystal lattice of SAS. SERS spectra are recorded in two types of silver colloids. Colloid 1 adsorbs MASS through the nitrogen atom of (\mathrm{CH}{3} \mathrm{NH}{3}) group. There are two different adsorption sites for MASS in colloid 2. SAS is chemisorbed by colloid 2 through the oxygen atom of (\mathrm{SeO}{4}^{2-}). Shifting and splitting observed for the internal modes of (\mathrm{SeO}{4}^{2-}) on adsorption are due to the reduced local symmetry of the ion. (1) 1994 Academic Press. Inc.