Academic Journal

Geometry of Pentaphenylantimony in Solution: Support for a Trigonal Bipyramidal Assignment from X‑ray Absorption Spectroscopy and Vibrational Spectroscopic Data

التفاصيل البيبلوغرافية
العنوان: Geometry of Pentaphenylantimony in Solution: Support for a Trigonal Bipyramidal Assignment from X‑ray Absorption Spectroscopy and Vibrational Spectroscopic Data
المؤلفون: Brent Lindquist-Kleissler (10058899), Monica Weng (10925477), Pierre Le Magueres (7627886), Graham N. George (812214), Timothy C. Johnstone (1312911)
سنة النشر: 1753
المجموعة: Smithsonian Institution: Digital Repository
مصطلحات موضوعية: Biophysics, Biochemistry, Genetics, Neuroscience, Cancer, Statistics, Virology, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, THF, solution-state Raman data, edge XAS spectra, Vibrational Spectroscopic Data Pent., fluxional main-group compounds, nonsolvated SbPh 5, spectroscopic time scale, Sb L III pre-edge features, Sb X-ray absorption spectroscopy, NMR, Trigonal Bipyramidal Assignment, bipyramidal SbPh 5, SbPh 5, vibrational spectroscopic studies, bipyramidal geometry
الوصف: Pentaphenylantimony (SbPh 5 ) has been previously crystallized in either a square pyramidal or trigonal bipyramidal geometry. Investigation of the solution-state structure of SbPh 5 has been hampered by the extreme fluxionality of this compound, but previous vibrational spectroscopic studies concluded that it maintains a square pyramidal geometry in solution. This non-VSEPR-compliant geometry, which is also assumed by BiPh 5 in the solid state, stands in contrast to the trigonal bipyramidal geometries of PPh 5 and AsPh 5 . A range of phenomena have been invoked to explain this discrepancy, most notably, the increased importance of relativistic effects as group 15 is descended. We present crystallographic, spectroscopic, and computational data revealing that SbPh 5 in fact assumes the VSEPR-compliant trigonal bipyramidal geometry in solution. In particular, Sb X-ray absorption spectroscopy (XAS) was used to obtain geometry-sensitive spectra that do not suffer from the slow spectroscopic time scale that has prevented NMR studies from elucidating the structure of this fluxional molecule. Sb K-edge and L III -edge XAS spectra of crystalline solids featuring SbPh 5 in either a square pyramidal (nonsolvate) or trigonal bipyramidal (cyclohexane hemisolvate or THF hemisolvate) form were compared to spectra of SbPh 5 in solution. The solution-state spectra agree with those from solids containing trigonal bipyramidal SbPh 5 . The most diagnostic spectroscopic feature was the distribution of intensity in the Sb L III pre-edge features. These distributions were rationalized using time-dependent density functional theory calculations that take into account spin–orbit coupling. Our use of Sb XAS not only resolves a long-standing physical inorganic question but also demonstrates more widely the utility of XAS in establishing the structures of fluxional main-group compounds. This conclusion was further supported by solid- and solution-state Raman data. Finally, we note that the present high-resolution diffraction data allow τ ...
نوع الوثيقة: article in journal/newspaper
اللغة: unknown
Relation: https://figshare.com/articles/journal_contribution/Geometry_of_Pentaphenylantimony_in_Solution_Support_for_a_Trigonal_Bipyramidal_Assignment_from_X_ray_Absorption_Spectroscopy_and_Vibrational_Spectroscopic_Data/14736452
DOI: 10.1021/acs.inorgchem.1c00496.s001
الاتاحة: https://doi.org/10.1021/acs.inorgchem.1c00496.s001
Rights: CC BY-NC 4.0
رقم الانضمام: edsbas.B3E18E54
قاعدة البيانات: BASE
الوصف
DOI:10.1021/acs.inorgchem.1c00496.s001