Vibrational spectra of transition element compounds

Abstract

Scandium, yttrium and the lanthanidesLaser-ablated scandium atoms react with H 2 O/N 2 mixtures to give matrix-trapped (Z 1 -N 2 )Sc(H)OH, (Z 1 -N 2 ) 2 Sc(H)OH and (Z 2 -N 2 )Sc(H)OH. nScH assignments, based on isotopic shifts and DFT calculations, are listed in Table 1. 1 The FTIR spectrum of Sc 3 N@C 80 gave assignments for two isomers-both with trigonal planar Sc 3 N units. 2 There is IR evidence that ScO + in noble gas matrices forms adducts [ScO(Ng) 5Àn (Ng 0 ) n ] + , where n = 0-5, Ng, Ng 0 = Ar, Kr, Xe. nScO assignments are given in Table 2. 3 Laser-evaporated ScO and N 2 , or Sc atoms and N 2 O form the matrix-trapped species OSc(Z 2 -N 2 ). This rearranges to an Z 1 -form (OScNN) on UV irradiation. nScO for the former is at 906.5 cm À1 , and for the latter at 894.6 cm À1 . 4 The Raman spectrum of [Sc(OSMe 2 ) 6 ] 3+ includes symmetric (a g ) and degenerate (e g ) nScO modes at 429, 451 cm À1 , respectively. The IR spectrum includes bands at 452 and 463 cm À1 due to e u , a u modes, respectively. 5 Ab initio calculations gave skeletal vibrational wavenumbers for Sc(mda) 3 ,where mda = C 3 H 3 O 2 À . 6 Raman studies have revealed grain-size effects for nanocrystalline ZrO 2 -Sc 2 O 3 , i.e. (ZrO 2 ) 1Àx (Sc 2 O 3 ) x , where x = 0.02-0.16. 7 The IR and Raman spectra of M 2 (M 0 O 4 ) 3 , where M = Sc, In, M 0 = Mo, W, gave characteristic assignments. For Sc 2 (MoO 4 ) 3 , variable-temperature spectra show the effects of the ferroelastic phase transition. 8 There have been two other reports of Raman studies of the phase behaviour of Sc 2 (MoO 4 ) 3 . 9,10 Raman spectroscopy was used to characterise intermediate compositions in the systems Ln 2 S 3 -Ln 0 2 S 3 , where Ln = La, Dy, L 0 = Sc, Lu etc. 11 The variable-temperature Raman spectra of Rb 2 KScF 6 (elpasolite) were used to follow temperature-induced phase transitions (using both ScF 6 and lattice modes). 12 The IR spectra of MCl 2 (k 3 -L)(thf), where M = Sc, Y, HL = (1), R = COOH, CSSH and CH 2 OH, include nMS near 300 cm À1 , and nMO (R = CH 2 OH) 570 cm À1 . 13 Characteristic Raman bands were seen at 204 and 42 cm À1 for a superconducting YNi 2 B 2 C single crystal. 14 The IR spectrum of Y 2 O 3 shows that nY-O shifts to lower wavenumber with decreased particle size. 15 Variable-temperature Raman spectroscopy was used to follow phase transitions of Y 2 O 3 -ZrO 2 . 16 IR and Raman spectra gave vibrational wavenumbers for orthorhombic M 2 BaCuO 5 , where M = Y, Ho or Gd, assigned using a short-range force constant model. 17 The Raman spectra of Ln 3 NbO 7 , where Ln = Y, La, Nd, Gd, in the temperature range 298-973K gave evidence for reversible structural disordering on increasing temperature. 18 IR data, together with previous Raman bands, gave assignments for KY 3 F 10 single crystals, supported by a normal coordinate analysis. 19 The IR and Raman spectra of [Ln(OH 2 ) 9 ] 3+ , where Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, gave detailed assignments for the LnO 9 unit (D 3h ). 20 Structural characteristics of MFeGe 2 O 7 , where M...

New Method of Production and Characterization of Haemozoin and Β-Haemozoin from Meccus longipennis

“…Furthermore, the band in FT-IR studies that corresponds to the stretching vibration of the Fe-N bond (reported for the formation of metal complexes) presents transmittance peaks (region c) of 2160 to 2315 cm −1 (28). Observing the same vibration in β-Hz at 2275 cm and a shoulder at 2310 cm −1 , while Hz is 2318 cm −1 .…”