Chemistry can be defined as the study of matter and the changes it undergoes. You¡¯ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology. 920-66-1, Name is 1,1,1,3,3,3-Hexafluoropropan-2-ol, molecular formula is , belongs to pyridazines compound. In a document, author is Aranda, Daniel, HPLC of Formula: C3H2F6O.
Charge transfer at the nanoscale and the role of the out-of-plane vibrations in the selection rules of surface-enhanced Raman scattering
Surface-enhanced Raman scattering (SERS) spectroscopy of pyridazine shows the selective enhancement of the bands recorded at about 1570, 1450 and 380 cm(-1), which are assigned to two different types of vibrations. The first two correspond to in-plane 8a;(ring) and 19b;(CH) totally symmetric A(1) modes, respectively, while the last band is assigned to the out-of-plane 16b;(ring),B-1 vibration. The selective enhancement has been analyzed on the basis of a resonant Raman process involving photoexcited metal (M)-to-molecule (A) charge transfer (CT: M-A + h M+-A(-)) states of the metal-adsorbate surface complex, which have also been related to the doublet electronic states of the corresponding radical anion of the adsorbate (A(-)). According to the selection rules of the electromagnetic/plasmonic SERS enhancement mechanism, the simultaneous enhancement of in-plane and out-of-plane modes could be attributed to different orientations of the adsorbate (perpendicular and parallel, respectively, or tilted) with respect to the metallic surface. The calculated resonance Raman-CT spectra (SERS-CT) and the vibrational wavenumbers of isolated pyridazine and of the pyridazine-Ag-2 complex obtained from electronic structure calculations suggest a single type of molecule adsorbed with perpendicular orientation. The relative SERS enhancements of both in-plane and out-of-plane modes are due to Franck-Condon factors related to differences between the equilibrium geometries (A(1) vibrations, Q 0) and gradients (B-1 vibrations, 0 and Q 0), respectively, of the potential energy surfaces of the involved ground and photoinduced CT electronic states. Therefore, the selective enhancement of the SERS bands of pyridazine is controlled by a general metal-to-molecule resonant CT mechanism. This conclusion supports the usefulness of SERS in studying the subtle electronic structure of charged interfaces as well as key processes such as electron transfer at the nanoscale.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 920-66-1, in my other articles. HPLC of Formula: C3H2F6O.
Reference:
Pyridazine – Wikipedia,
,Pyridazine | C4H4N2 – PubChem