New insight into the pectolite – serandite series: a single crystal diffraction study of Na(Ca 1.73 Mn 0.27 )[HSi 3 O 9 ] at 293 and 100 K

• Published in: Zeitschrift für Kristallographie - Crystalline Materials
• Main Authors: Arakcheeva, Alla, Pattison, Philip, Meisser, Nicolas, Chapuis, Gervais, Pekov, Igor V., Thélin, Philippe
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2007
• Subjects: Inorganic Chemistry; Condensed Matter Physics; General Materials Science; Kola Peninsula; Khibiny; Koashva; kola peninsula
• Online Access: http://dx.doi.org/10.1524/zkri.2007.222.12.696; https://www.degruyter.com/document/doi/10.1524/zkri.2007.222.12.696/xml; https://www.degruyter.com/document/doi/10.1524/zkri.2007.222.12.696/pdf

Using synchrotron radiation, a single crystal investigation has been performed at 293 and 100 K for the structural characterization of the manganoan pectolite, Na(Ca 1.73 Mn 0.27 )[Si 3 O 8 (OH)] (from the pegmatite at Mt. Koashva, Khibiny alkaline massif, Kola peninsula, Russia). The data obtained are compared with other members of the pectolite – serandite, Na(Ca 2–x Mn x )[Si 3 O 8 (OH)], series. The strong asymmetric hydrogen bond observed in the other members of the series has been confirmed at 293 K (O3–O4 = 2.473(3) Å; H–O3 = 0.97(4) Å, H … O4 = 1.50(4) Å O3–H … O4 = 178(4)°). This bond exhibits strengthening (O3–O4 = 2.458(2) Å) and becomes more symmetric at 100 K (H–O3 = 1.06(4) Å, H … O4 = 1.40(4) Å, O3–H … O4 177(4)°). The data obtained for 293 K confirm the previously hinted tendency: the higher the content of Mn, the more asymmetric the H-bond. The influence of the asymmetric position of the H-bond on the environment close to the bonded O3 and O4 atoms and the H–Na interaction are discussed. The alternative topological role of the hydrogen bond is considered in comparison to a similar structure Li 2 Mg 2 [Si 4 O 11 ].