The Potassium carbonate (synthetic) (K2CO3) Raman spectrum and its interpretation are presented below.
Potassium carbonate sample data
| Description: | Potassium carbonate mineral sample |
|---|---|
| Mineral: | Potassium carbonate (synthetic) (K2CO3) |
| RAMAN ID: | RAMANK2CO3s |
| Ideal chemistry: | K2CO3 |
| Source: | Grigore Cobălcescu Museum |
| Locality: | – |
| Owner: | Department of Geology – Alexandru Ioan Cuza University of Iasi |
Potassium carbonate sample image
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Raman spectrum of Potassium carbonate (synthetic) (K2CO3)
Main Raman bands of Potassium carbonate (synthetic) (K2CO3)
| Wavenumbers (cm-1): | 1063vs |
|---|
Raman parameters
| Instrument settings: | Raman spectrograph HE 532nm (Horiba Jobin-Yvon) |
|---|---|
| Spectral resolution: | 2 cm-1 |
| Conditions of measurement: | at room temperature |
Interpretation of Raman spectrum of Potassium carbonate (synthetic) (K2CO3)
The Raman spectrum of K2CO3 shows a couple of bands at 1026 and 1063 cm-1 that may be attributed to the ν1 symmetric stretching mode. The two bands may be explained by the presence of the molecules belonging to two structures, C2v bidentate form and D3h, in agreement with the theoretical values calculated by Koura et al. (1996). The ν2 vibration mode is not Raman active. The bands at 1374 cm-1 and 1426 cm-1, can be assigned to ν3a respectively ν3b. To the ν4 mode (doubly degenerate symmetric bending) are attributed the values of 677 cm-1 (ν4a) and 702 cm-1 (ν4b). The spectrum also presents three bands at 237 cm-1, 287 cm-1 and 484 cm-1, which may be assigned to the external vibration modes between the cation and anionic group (T(K,CO3)).
The frequency of the detected bands is reported in below table.
| Buzgar and Apopei, 2009 | Koura, 1966 | Koura, 1966 | Assignment |
| Calculated | Measured | ||
| 237 288 484 |
76, 85 122, 252, 278, 291 |
126, 141, 192 |
T(K,CO3) |
| 677 | 688 | 692 | ν4a (E’) symmetric deformation |
| 702 | 706 | 697 | ν4b (E’) symmetric deformation |
| 1026 1063 |
1025 | 1043 1064 |
ν1 (A’1) symmetric stretch |
| 1374 | 1385 | 1405 | ν3a (E’) asymmetric stretch |
| 1426 | 1557 | ν3b (E’) asymmetric stretch |
NO = not observed; NA = not assigned
References for the Raman spectrum of Potassium carbonate
- BUZGAR N., APOPEI A. I. (2009) – The Raman study on certain carbonates. Analele Stiintifice ale Universitatii “Al. I. Cuza” – Iasi, Tome 55, issue 2, 97-112 [link]
- KOURA N., KOHARA S., TAKEUCHI K., TAKAHASI S., CURTISS L. A., GRIMSDITCH M., SABOUNGI M. L. (1996) – Alkali carbonates: Raman spectroscopy, ab initio calculations and structure. Journal of Molecular Structure, 382, p. 163-169 [link]