Hydrogen bond strength in some beryllium salts, BeXO44H2O and Me2Be(XO4)22×H2O (X=S, Se; Me=K, Rb): Correlation of structural data and infrared spectra
- Autor(en)
- Manfred Wildner, Mitko Georgiev
- Abstrakt
IR spectra of the title compds. are presented and discussed in the regions of the uncoupled O-D stretches of matrix-isolated HDO mols. (isotopically dil. samples). The strengths of the hydrogen bonds are analyzed in terms of the resp. OwO bond distances, the Be-OH2 interactions (synergetic effect), the proton acceptor capabilities of the sulfate and selenate oxygen atoms as deduced from Brown's bond valence sums of the oxygen atoms, the anti-cooperative effect (proton acceptor and proton donor competitive effect). The IR spectroscopic expts. reveal that comparatively strong hydrogen bonds are formed in the compds. under study, analogical to other hydrated beryllium salts owing to the large ionic potential of the small Be2+ ions. The wavenumbers of .nu. OD show that the water mols. in BeSO44H2O and in the double salts are strongly energetically distorted, i.e. their local symmetries deviate remarkably from the C 2v mol. symmetry (for example, .nu. have values of 74 and 36 cm-1 for H2O(1) and H2O(2) in K2Be(SO4)22H2O, and 119 cm-1 in BeSO44H2O). The hydrogen bonds in K2Be(SeO4)22H2O are stronger than those in K2Be(SO4)22H2O due to the stronger proton acceptor capability of the SeO4 2- ions. The proton donor strengths of the water mols. in K2Be(SO4)22H2O and K2Be(SeO4)22H2O are greater than those of the water mols. in BeSO44H2O and BeSeO44H2O (i.e. larger deviations from Mikenda's curve) due to the different compns. of the resp. beryllium tetrahedra-Be(XO4)2(H2O)2 in the double salts and Be(H2O)4 in the simple ones (proton donor competitive effect). The intramol. O-H bond lengths are derived from the .nu. OD vs. r OH correlation curve.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- University of Chemical Technology and Metallurgy
- Journal
- Solid State Sciences
- Band
- 11
- Seiten
- 1358-1362
- Anzahl der Seiten
- 5
- ISSN
- 1293-2558
- Publikationsdatum
- 2009
- Peer-reviewed
- Ja
- ÖFOS 2012
- 105113 Kristallographie, 1030 Physik, Astronomie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/f7a89329-5d0e-492b-8e19-724e1fe77be3