A variable temperature X-ray diffraction investigation of [PPN+][S4N5]: supramolecular interactions governing an order/disorder transformation and the first high resolution X-ray structure of the anion
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Date
2014
Authors
Boeré, René T.
Roemmele, Tracey L.
Krall, Maria K.
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI AG
Abstract
The title salt, triphenyl(P,P,P-triphenylphosphineimidato-N)-phosphorus(1+)
1,3,5,7-tetrathia(1,5-SIV)-2,4,6,8,9-pentaazabicyclo[3.3.1]nona-1,4,6,7-tetraene(1−), CAS
[48236-06-2], prepared by the literature method, is found by crystallography to be a 1:1
CH3CN solvate. Disorder exists for the N atoms of the anion. A VT crystal structure study
was conducted at 100 K, 120 K, 140 K, 172 K, 200 K, 240 K and 280 K. The 100 K
structure is superior, with only 10% of a second anion position oppositely-oriented w.r.t the
diad axis of point group 2mm. At 120 K, an adjacent two-site disorder is encountered, but
at higher temperatures three-site disorder with both opposite and adjacent placements of
S4N5
− ions is required w.r.t. the primary component. At 240 and especially 280 K, the
anion nitrogen atoms appear fully scrambled amongst the six possible sites on the edges of
an S4 tetrahedron with 83.3% occupancy for each. The PPN+ geometry does not show
strong cation-cation interactions. However, there are numerous supramolecular contacts
corresponding mostly to non-classical H-bonds between PPN+ ions and S4N5
− as well as
CH3CN. The geometry of the anion is corroborated from B3LYP/6-311++G(3df) DFT
calculations, and the infra-red spectrum was assigned with excellent agreement between
experimental and calculated frequencies.
Description
Sherpa Romeo green journal. Open access article. Creative Commons Attribution 3.0 LIcense (CC BY 3.0) applies
Keywords
Sulfur-nitride , Crystal structure , Disorder modelling , DFT calculations
Citation
Boere, R. T., Roemmele, T. L., & Krall, M. K. (2014). A variable temperature X-ray diffraction investigation of [PPN+][S4N5]: supramolecular interactions governing an order/disorder transformation and the first high resolution X-ray structure of the anion. Molecules, 2014(19), 1956-1975. doi:10.3390/molecules19021956