Vibrational spectroscopic investigation of the hydrates of manganese(II) oxalate

Abstract

The three known hydrates of manganese(II) oxalate, α-MnC 2 O 4 · 2H 2 O, γ -MnC 2 O 4 · 2H 2 O and MnC 2 O 4 · 3H 2 O were synthesized by known procedures and characterized by X-ray powder diffractometry. Their infrared (IR) and Raman spectra were recorded and discussed on the basis of its structural peculiarities allowing to establish some interesting relations between them and with other, previously investigated, oxalate complexes. The IR spectra of partially deuterated samples of α-MnC 2 O 4 · 2H 2 O were also discussed, reinforcing some of the performed assignments.

Non-invasive identification of metal-oxalate complexes on polychrome artwork surfaces by reflection mid-infrared spectroscopy

“…Based on the available vibrational data of several metal-oxalate complexes [32][33][34][35][36][37][38][39][40], the present work is aimed to extend knowledge by studying the reflection FTIR vibrational profiles and the corresponding spectral distortions due to the surface reflection of twelve metal oxalate-based complexes that can be reasonably revealed on alteration patinas of polychrome artworks.…”

Vibrational spectra of lead(II) oxalate

“…[4] These studies complement and extend those of other authors, related to the spectroscopic characterization of natural oxalates. [5 -15] The formation of biogenic lead oxalate dihydrate (PbC 2 O 4 ·2H 2 O) has just been demonstrated by in vitro experiments in which the very insoluble lead mineral piromorphite, Pb 5 (PO 4 ) 3 Cl, was solubilized by the organic acid-producing fungus Aspergillusniger with generation of the mentioned oxalate. [4,16] The analysis of this biomineral using X-ray diffractometry and scanning electron microscopy revealed the presence of PbC 2 O 4 ·2H 2 O as well as the corresponding anhydrous oxalate, which is apparently produced by slow decomposition of the dihydrate [16] which is known to be very unstable.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part IV

“…The three known hydrates of manganese(II) oxalate were synthesized by known procedures and characterized by X-ray powder diffractometry. In this study by Mancilla et al, [209] their IR and Raman spectra were recorded and discussed on the basis of their particular structural features. Ali et al [210] provide insight into thermally induced solid-state polymorphic transformation of sulfathiazole using simultaneous in situ Raman spectroscopy and DSC.…”

“…A monoclinic distortion of orthorhombic structure occurs in Bi 4 Ti 3 O 12 crystals at temperatures below 200 K. Basova et al [213] have carried out an experimental and theoretical investigation of the vibrational spectra of copper phthalocyanine, including polarized single-crystal Raman spectra, isotope effect, and DFT calculations. The IR and Raman spectra of anhydrous lead oxalate (PbC 2 O 4 ) were recorded and discussed by Mancilla et al [214] on the basis of its structural peculiarities, and comparisons with other previously investigated metallic oxalates were made. Das et al [215] have studied the mechanism of the recrystallization in epitaxial GaN under a dynamic stress field and described the atomic origin of its planar defect formation.…”