Journal ArticleDOI
Consistent porphyrin force field. 2. Nickel octaethylporphyrin skeletal and substituent mode assignments from nitrogen-15, meso-d4, and methylene-d16 Raman and infrared isotope shifts
TLDR
In this paper, the resonance Raman spectra with variable-wavelength excitation were reported for nickel octaethylporphyrin and its isotopomers containing {sup 15}N, and {sup 2}H at the methine (meso-d{sub 4}) and methylene (methylene-d-sub 16}) carbon atoms.Abstract:
Resonance Raman spectra with variable-wavelength excitation are reported for nickel octaethylporphyrin and its isotopomers containing {sup 15}N, and {sup 2}H at the methine (meso-d{sub 4}) and methylene (methylene-d{sub 16}) carbon atoms. The {sup 15}N, meso-d{sub 4} double isotopomer is also examined. The infrared spectrum of the methylene-d{sub 16} isotopomer is reported, and the frequencies are combined with recently published infrared results for the other isotopomers. Essentially all of the porphyrin skeletal modes have been assigned and have been allocated to local coordinates which recognize the pyrrole rings as cooperative vibrational units. The assignments are supported by a normal-coordinate analysis with a valence force field involving standard ethyl force constants and porphyrin in-plane force constants which are transferred nearly intact from Ni porphine and Ni tetraphenylporphine. Many vibrational modes of the NiOEP ethyl substituents have also been located in the spectra and assigned. Bands assignable to ethyl C-C stretching and C-H bending modes are surprisingly strong in the resonance Raman spectra and suggest appreciable involvement of the ethyl groups in the porphyrin {pi}-{pi}{sup *} excited states. The conformations of the ethyl substituents have a marked influence on the low-frequency vibrational spectra.read more
Citations
More filters
Journal ArticleDOI
Assignment of Protoheme Resonance Raman Spectrum by Heme Labeling in Myoglobin
TL;DR: In this paper, the Resonance Raman (RR) spectra are reported for myoglobin reconstituted with seven heme isotopomers which are labeled with 15N and meso-D4 in the porphyrin skeleton or at the propionate substituents.
Journal ArticleDOI
Photoinduced linkage isomers of transition-metal nitrosyl compounds and related complexes.
TL;DR: A review of the current knowledge in the still-developing field of light-induced changes in transition-metal nitrosyl complexes includes a discussion of photoinduced metastable linkage isomers of related substances.
Journal ArticleDOI
Ruffling in a Series of Nickel(II) meso-Tetrasubstituted Porphyrins as a Model for the Conserved Ruffling of the Heme of Cytochromes c.
Walter Jentzen,M. C. Simpson,J. D. Hobbs,X.Z. | Song,X.Z. | Song,Tadashi Ema,Nora Y. Nelson,Craig J. Medforth,Kevin M. Smith,M. Veyrat,Marinella Mazzanti,René Ramasseul,Jean-Claude Marchon,Toshihiko Takeuchi,William A. Goddard,John A. Shelnutt,John A. Shelnutt +16 more
TL;DR: A series of meso-tetrasubstituted porphyrins for which the substituents vary in size is investigated, expected to result in unique alterations of the chemical and physical properties of the nominally planar p Morphyrin macrocycle.
Journal ArticleDOI
Extension of the Universal Force Field to Metal-Organic Frameworks.
TL;DR: This work has extended the UFF parameter set to include transition metal elements Zn, Cu, Ni, Co, Fe, Mn, Cr, V, Ti, Sc, and Al, as they occur in MOFs, and has proposed additional O parameters that provide reliable structures of the metal oxide clusters of the connectors.
Journal ArticleDOI
Spectroscopic studies on the interaction between human hemoglobin and CdS quantum dots.
TL;DR: Results indicated that the sulfur atoms of the cysteine residues form direct chemical bonds on the surface of the CdS QDs, which does not significantly affect the spin state of the heme iron, and deoxidation is not expected to take place on the coated oxyhemoglobin.