James R. Vyvyan

Bio: James R. Vyvyan is an academic researcher from Western Washington University. The author has contributed to research in topics: Total synthesis & Epoxide. The author has an hindex of 16, co-authored 48 publications receiving 3661 citations. Previous affiliations of James R. Vyvyan include University of Minnesota & Hope College.

Introduction to Spectroscopy

Abstract: 1. Molecular Formulas and What Can Be Learned from Them. 2. Infrared Spectroscopy. 3. Nuclear Magnetic Resonance Spectroscopy Part One: Basic Concepts. 4. Nuclear Magnetic Resonance Spectroscopy Part Two: Carbon-13 Spectra, Including Heteronuclear Coupling with Other Nuclei. 5. Nuclear Magnetic Resonance Spectroscopy Part Three: Spin-Spin Coupling. 6. Nuclear Magnetic Resonance Spectroscopy Part Four: Other Topics in One-Dimensional NMR. 7. Ultraviolet Spectroscopy. 8. Mass Spectrometry. 9. Combined Structure Problems. 10. Nuclear Magnetic Resonance Spectroscopy Part Five: Advanced NMR Techniques. Answers to Selected Problems. Appendix 1: Infrared Absorption Frequencies of Functional Groups. Appendix 2: Some Representative Chemical Shift Values for Various Types of Protons. Appendix 3: Typical Proton Coupling Constants. Appendix 4: Calculation of Proton (1H) Chemical Shifts. Appendix 5: Calculation of Carbon-13 Chemical Shifts. Appendix 6: 13C Coupling Constants. Appendix 7: Tables of Precise Masses and Isotopic Abundance Ratios for Molecular Ions Under Mass 100 Containing Carbon, Hydrogen, Nitrogen, and Oxygen. Appendix 8: Common Fragment Ions Under Mass 105. Appendix 9: Handy-Dandy Guide to Mass Spectral Fragmentation Patterns. Appendix 10: Index of Spectra.

Dopamine functions as an antiherbivore defense in the temperate green alga Ulvaria obscura.

Abstract: On northeastern Pacific coasts, Ulvaria obscura is a dominant component of subtidal "green tide" blooms, which can be harmful to marine communities, fisheries, and aquaculture facilities. U. obscura is avoided by herbivores relative to many other locally common macrophytes, which may contribute to its ability to form persistent blooms. We used a bioassay-guided fractionation method to experimentally determine the cause of reduced feeding on Ulvaria by echinoderms, molluscs, and arthropods. Our results indicated that dopamine, which constituted an average of 4.4% of the alga's dry mass, was responsible for decreased feeding by sea urchins (Strongylocentrotus droebachiensis). Subsequent experiments demonstrated that dopamine also reduced the feeding rates of snails (Littorina sitkana) and isopods (Idotea wosnesenskii). Dopamine is a catecholamine that is a common neurotransmitter in animals. The catecholamines dopamine, epinephrine (adrenaline), and norepinephrine also occur in at least 44 families of higher plants. The functions of catecholamines in plants are less well known than in animals but are likely to be diverse and include both physiological and ecological roles. Our results are the first experimental demonstration of a plant or algal catecholamine functioning as a feeding deterrent. This novel use of dopamine by Ulvaria may contribute to the formation and persistence of harmful Ulvaria blooms in northeastern Pacific coastal waters.

A Practical Guide to First-Order Multiplet Analysis in 1H NMR Spectroscopy

Abstract: The ability to deduce the proper set of coupling constant (J) values from a complex first-order multiplet in a 1 H NMR spectrum is an extremely important asset. This is particularly valuable to the task of assigning relative configurations among two or more stereocenters in a molecule. Most books and treatises that deal with coupling constant analysis address the address useful operation of generating splitting trees to create the line pattern from a given set of J values. Presented here are general and systematic protocols for the converse, i.e., for deducing the complete set of J values from the multiplet

The Halogen Bond

Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

Dispersive Fourier transformation for fast continuous single-shot measurements

Abstract: It's challenging to measure non-repetitive events in real time in the field of instrumentation and measurement. Dispersive Fourier transformation is an emerging method that permits capture of rare events, such as optical rogue waves and rare cancer cells in blood. This Review article covers the principle of dispersive Fourier transformation and its implementation in diverse applications.