Inelastic neutron scattering spectra of free base and zinc porphines: A comparison with DFT-based vibrational analysis

Nina Verdal, Pawel M. Kozlowski, Bruce S. Hudson

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Inelastic neutron scattering (INS) spectra of free base (FBP) and zinc (ZnP) porphines are presented and compared with the results of density functional theory (DFT) calculations using the B3LYP functional with 6-31G(d) or 6-311G(d,p) basis sets. To obtain quantitative agreement between experiment and theory, two different scaling techniques have been applied: a scaled quantum mechanical (DFT-SQM) force field was developed for B3LYP/6-31G(d) calculations and the uniform frequency scaling technique (DFT-UFS) was applied to B3LYP/6-311G(d,p) results. The DFT-SQM calculations have been previously compared with IR and Raman spectra with good agreement, which allows for a nearly complete vibrational assignment. The results of the present study extend previous vibrational analysis to a higher level of reliability and complexity. The previous results are augmented by the comparison of calculated and observed INS intensities and the comparison of calculated modes with those observed in INS spectra but previously unobserved in optical spectra. Excellent agreement is acquired between the INS spectra and the results of both calculations, permitting a more detailed and reliable description of the vibrational properties of porphyrins.

Original languageEnglish (US)
Pages (from-to)5724-5733
Number of pages10
JournalJournal of Physical Chemistry A
Volume109
Issue number25
DOIs
StatePublished - Jun 30 2005

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Inelastic neutron scattering spectra of free base and zinc porphines: A comparison with DFT-based vibrational analysis'. Together they form a unique fingerprint.

Cite this