Computational study of 19F NMR spectra of double four ring-containing Si/Ge-zeolites

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry
Angeles PulidoAvelino Corma

Abstract

(19)F NMR chemical shifts are calculated in order to study the F(-) environment in double four ring (D4R) containing Si/Ge-zeolites. The calculations with the DFT/CSGT/B3PW91 methodology yielded an agreement within 2 ppm with respect to the experimental peaks corresponding to the D4R units containing 8Si0Ge, 7Si1Ge and 0Si8Ge of the octadecasil zeolite. The optimisation of the 7Si1Ge-, 6Si2Ge-, 5Si3Ge- and 4Si4Ge-D4R units with DFT/B3LYP methodology shows that a covalent Ge-F bond is formed and therefore a Ge atom in the D4R is pentacoordinated. The displacement of the fluoride ion towards a Ge atom in the Ge-containing D4R units locates four Si/Ge atoms in the close vicinity of the F(-) and this makes possible a rationalization of the (19)F NMR signals in groups according to the number of Si (n) and Ge (m) atoms in the nearest F(-) environment, F-Si(n)Ge(m) (where n+m=4). Thus, the calculated chemical shifts show that higher values are observed when the number of Ge atoms in the nearest F(-) environment increases.

References

Jun 15, 1992·Physical Review. B, Condensed Matter·J P Perdew, Y Wang
Oct 28, 1996·Physical Review Letters·J P PerdewM Ernzerhof
Oct 26, 2002·Chemical Communications : Chem Comm·Luis A VillaescusaRussell E Morris
Oct 14, 2004·Journal of the American Chemical Society·Teresa BlascoJosé A Vidal-Moya
May 7, 2005·Chemical Communications : Chem Comm·German SastreAvelino Corma
Aug 17, 1998·Angewandte Chemie·Miguel A CamblorRussell E Morris

❮ Previous
Next ❯

Citations

Feb 22, 2007·Physical Chemistry Chemical Physics : PCCP·German Sastre
May 7, 2015·Chemical Society Reviews·Pavla EliášováJiří Čejka
May 16, 2015·Chemical Society Reviews·Veronique Van SpeybroeckC Richard A Catlow
Dec 6, 2012·Dalton Transactions : an International Journal of Inorganic Chemistry·Jie SuXiaodong Zou
May 14, 2016·Physical Chemistry Chemical Physics : PCCP·Thuat T TrinhPhilippe Sautet
Oct 3, 2017·Chemistry : a European Journal·Yi LuoWeimin Yang
Jun 9, 2020·Angewandte Chemie·Maksym OpanasenkoJiří Čejka
Mar 4, 2017·Acta Crystallographica. Section C, Structural Chemistry·Eddy DibBruno Alonso

❮ Previous
Next ❯

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.