The structure of whewellite, CaC2O4. H2O at 328 K

The Tetrahydroxydicarbenium Cation [(HO)2CC(OH)2]2+: Synthesis and Structure

“…The reason for this most likely is intermolecular charge repulsion, like it is reported for Na 2 C 2 O 4 (C‐O: 1.534(3) Å and 1.654(3) Å). Combining this charge repulsion with intermolecular hydrogen bonding, which is for instance reported for CaC 2 O 4 ⋅H 2 O, all four C‐O bond distances are equal (1.253(4) Å) . This special case also applies to [(HO) 2 CC(OH) 2 ][SbF 6 ] 2 ⋅4H 2 O described by Minkwitz et al ., resulting in four equal C‐O bond distances.…”

Characterization of agave bagasse as a function of ionic liquid pretreatment

“…Fig. 2 shows the XRD patterns of untreated AGB and the calculated pattern for calcium oxalate monohydrate, generated from the published crystal structure by Deganello [24]. [26].…”

Vibrational Signatures of Calcium Oxalate Polyhydrates

“…More recently, several studies have helped to refine the structural parameters of the COM, in particular those from Tazzoli et al, [14] Hochrein et al, [15] and Deganello et al. [16] These investigations have established COM structures at different temperatures and have shown that there can be a reversible change in space group from P2 1 /c to I2/m at 328 K. Finally, a neutron diffraction study by Daudon et al [17] on a single crystal of COM allowed to locate the proton positions of the water molecules of the structure. Therefore, this structure has been chosen as the starting geometry for our calculations.…”