English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Polarized infrared absorption spectra of thin, oriented single-crystal slabs of pectolite and serandite were recorded between 4000 and 350 cm -1  at 298 and 83 K. The spectra of both minerals show a broad absorption region parallel to the silicate chains (b direction) that is centered around 1000 cm -1  which is interrupted by a transmission window, and which is superimposed by sharp silicate, lattice, and overtone modes. This band is assigned to the OH stretching mode consistent with the alignment of the O-H O hydrogen bond parallel to b and the short O···O distance of 2.45-2.48 Å that was found in previous X- ray structure refinements. At 1396 cm -1  (pectolite) and 1386 cm -1  (serandite) an OH bending mode is observed in the IR spectra parallel to c. At low temperatures, this mode shifts up to higher frequencies (1403 cm -1  at 83 K in pectolite). whereas the down-shift of the OH stretching mode cannot be observed due to the extremely broad band width. The slightly higher energy of the bending mode in pectolite indicates a slightly stronger hydrogen bond with respect to serandite. However, the bond length in serandite is slightly shorter than that in pectolite. An asymmetric O-H ··· O bond is confirmed in pectolite and serandite through comparison with different materials with similar, very strong hydrogen bonds and low-energy OH stretching modes.

Single-crystal IR spectroscopy of very strong hydrogen bonds in pectolite, NaCa 2 [Si 3 O 8 (OH)], and serandite, NaMn 2 [Si 3 O 8 (OH)]