scispace - formally typeset
Search or ask a question
Author

Steve Scheiner

Bio: Steve Scheiner is an academic researcher from Utah State University. The author has contributed to research in topics: Hydrogen bond & Ab initio. The author has an hindex of 73, co-authored 472 publications receiving 21087 citations. Previous affiliations of Steve Scheiner include Air Force Research Laboratory & University of Białystok.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, a novel definition for the hydrogen bond is proposed, which takes into account the theoretical and experimental knowledge acquired over the past century, and six criteria are listed that could be used as evidence for the presence of a hydrogen bond.
Abstract: A novel definition for the hydrogen bond is recommended here. It takes into account the theoretical and experimental knowledge acquired over the past century. This def- inition insists on some evidence. Six criteria are listed that could be used as evidence for the presence of a hydrogen bond.

1,367 citations

Book
04 Sep 1997
TL;DR: In this paper, the authors propose a Quantum Chemical Framework (QCF) and a Vibrational Spectra (VSS) to describe the properties of the potential energy surface.
Abstract: 1 Quantum Chemical Framework 2 Geometries and Energetics 3 Vibrational Spectra 4 Extended Regions of Potential Energy Surface 5 Cooperative Phenomena 6 Questionable Cases

1,074 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the CH-O interaction between FnH3-nCH as proton donor and H 2O, CH3OH, and H2CO as acceptor and found that the interaction is quite weak with CH4 as donor but is enhanced by 1 kcal/mol with each F added to the donor.
Abstract: Ab initio calculations are used to analyze the CH···O interaction between FnH3-nCH as proton donor and H2O, CH3OH, and H2CO as acceptor. The interaction is quite weak with CH4 as donor but is enhanced by 1 kcal/mol with each F added to the donor. The CH···O interaction behaves very much like a conventional OH···O H-bond in most respects, including shifts in electron density that accompany the formation of the bond and the magnitudes of the various components of the interaction energy. The two sorts of H-bonds also gravitate toward a similar equilibrium geometry and are comparably sensitive to deformations from that structure. In a quantitative sense, while both CH···O and OH···O prefer a linear configuration, the former is somewhat more easily bent and is less sensitive to stretches from its equilibrium H-bond length. Whereas the OH bond has been shown to stretch and undergo a red shift in its vibrational frequency upon formation of a H-bond, the CH bond of the molecules studied here follows the opposite ...

864 citations

Journal ArticleDOI
TL;DR: In this paper, a new definition of the hydrogen bond is proposed, which emphasizes the need for evidence, and a list of criteria has been provided, and these can be used as evidence for hydrogen bond formation.
Abstract: The term "hydrogen bond" has been used in the literature for nearly a century now. While its importance has been realized by physicists, chemists, biologists, and material sci- entists, there has been a continual debate about what this term means. This debate has inten- sified following some important experimental results, especially in the last decade, which questioned the basis of the traditional view on hydrogen bonding. Most important among them are the direct experimental evidence for a partial covalent nature and the observation of a blue-shift in stretching frequency following X-HY hydrogen bond formation (XH being the hydrogen bond donor and Y being the hydrogen bond acceptor). Considering the recent experimental and theoretical advances, we have proposed a new definition of the hydrogen bond, which emphasizes the need for evidence. A list of criteria has been provided, and these can be used as evidence for the hydrogen bond formation. This list is followed by some char- acteristics that are observed in typical hydrogen-bonding environments.

809 citations

Journal ArticleDOI
TL;DR: In this article, the electronic structure and bonding in metal phthalocyanines (Fe, Co, Ni, Ni and Zn) were investigated in detail using a density functional method, and the calculated orbital energy levels and relative total energies of these D4h structures indicate that Fe and Co phalcanine have 3A2g and 2Eg ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands.
Abstract: Electronic structure and bonding in metal phthalocyanines (Metal=Fe, Co, Ni, Cu, Zn, Mg) is investigated in detail using a density functional method. The metal atoms are strongly bound to the phthalocyanine ring in each case, by as much as 10 eV. The calculated orbital energy levels and relative total energies of these D4h structures indicate that Fe and Co phthalocyanines have 3A2g and 2Eg ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands. The valence electronic structures of Fe and Co phthalocyanines differ significantly from those of the others. The HOMOs in Fe, Co, and Cu phthalocyanine are metal 3d-like, whereas in Ni and Zn phthalocyanines, the HOMO is localized on the phthalocyanine ring. The first ionization removes an electron from the phthalocyanine a1u orbital in all cases, with very little sensitivity of the ionization energy to the identity of the metal. Whereas the first reduction in Fe and Co phthalocyanine occurs at the metal, i...

537 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
TL;DR: The hydrogen bond is the most important of all directional intermolecular interactions, operative in determining molecular conformation, molecular aggregation, and the function of a vast number of chemical systems ranging from inorganic to biological.
Abstract: The hydrogen bond is the most important of all directional intermolecular interactions. It is operative in determining molecular conformation, molecular aggregation, and the function of a vast number of chemical systems ranging from inorganic to biological. Research into hydrogen bonds experienced a stagnant period in the 1980s, but re-opened around 1990, and has been in rapid development since then. In terms of modern concepts, the hydrogen bond is understood as a very broad phenomenon, and it is accepted that there are open borders to other effects. There are dozens of different types of X-H.A hydrogen bonds that occur commonly in the condensed phases, and in addition there are innumerable less common ones. Dissociation energies span more than two orders of magnitude (about 0.2-40 kcal mol(-1)). Within this range, the nature of the interaction is not constant, but its electrostatic, covalent, and dispersion contributions vary in their relative weights. The hydrogen bond has broad transition regions that merge continuously with the covalent bond, the van der Waals interaction, the ionic interaction, and also the cation-pi interaction. All hydrogen bonds can be considered as incipient proton transfer reactions, and for strong hydrogen bonds, this reaction can be in a very advanced state. In this review, a coherent survey is given on all these matters.

5,153 citations

Journal ArticleDOI
TL;DR: In this critical review, recent progress in the area ofAIE research is summarized and typical examples of AIE systems are discussed, from which their structure-property relationships are derived.
Abstract: Luminogenic materials with aggregation-induced emission (AIE) attributes have attracted much interest since the debut of the AIE concept in 2001. In this critical review, recent progress in the area of AIE research is summarized. Typical examples of AIE systems are discussed, from which their structure–property relationships are derived. Through mechanistic decipherment of the photophysical processes, structural design strategies for generating new AIE luminogens are developed. Technological, especially optoelectronic and biological, applications of the AIE systems are exemplified to illustrate how the novel AIE effect can be utilized for high-tech innovations (183 references).

4,996 citations