Analysis of Low-Lying Gerade Rydberg States of Acetylene Using Two-Photon Resonance Fluorescence Excitation Spectroscopy
The np gerade Rydberg states of acetylene were analyzed using two-photon resonance fluorescence excitation spectroscopy in the 72 000–93 000 cm–1 energy region. The npπ1Σg+ and npπ1Δg Rydberg series (n = 3–5) were identified in the fluorescence excitation spectrum measured by monitoring the C2 d3Πg–a3Πu Swan system. Some vibronic bands were assigned to the npπ1Δg–X̃1Σg+ transition on the basis of rotational analysis. The 5pσ1Πg state was observed, which is the first such observation in an npσ1Πg series. Rotational analysis of the 5pσ1Πg–X̃1Σg+ transition showed e/f-symmetry dependent predissociation of acetylene in the 5pσ1Πg state. The 000 band of the deuterated acetylene (C2D2) 4pπ1Σg+–X̃1Σg+ transition exhibits an atypical structure, which was satisfactorily reproduced by a simple model of quantum interference between the discrete and quasi-continuum states. The predissociative lifetimes of the npπgerade Rydberg states were estimated from the spectral profiles. The predissociation mechanism of acetylen...
We recently generalized the formerly alignment-dependent multivariate image analysis applied to quantitative structure–activity relationships (MIA-QSAR) method through the application of the discrete Fourier transform (DFT), allowing for its application to noncongruent and structurally dive ... more
Poly-ADP-ribosylation (PARylation) is a protein posttranslational modification (PTM) that is critically involved in many biological processes that are linked to cell stress responses. It is catalyzed by a class of enzymes known as poly-ADP-ribose polymerases (PARPs). In particular, PARP1 is ... more
This review focuses on the type A cytochrome c oxidases (CcO), which are found in all mitochondria and also in several aerobic bacteria. CcO catalyzes the respiratory reduction of dioxygen (O2) to water by an intriguing mechanism, the details of which are fairly well understood today as a r ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more