Jerzy Leszczynski

Bio: Jerzy Leszczynski is an academic researcher from Jackson State University. The author has contributed to research in topics: Ab initio & Density functional theory. The author has an hindex of 78, co-authored 993 publications receiving 27231 citations. Previous affiliations of Jerzy Leszczynski include National Academy of Sciences of Ukraine & Yale University.

COMPUTATIONAL CHEMISTRY: Reviews of Current Trends

Abstract: One-Electron Equations for Embedded Electron Density: Challenge for Theory and Practical Payoffs in Multi-Level Modeling of Complex Polyatomic Systems (T A Wesolowski) Density-Functional Based Investigation of Molecular Magnets (M R Pederson et al.) Vibrational Spectra by Electron Impact: Theoretical Models for Intensities (P arsky & R urik) Theoretical Description of the Kinetics of Gas-Phase Reactions Important in Atmospheric Chemistry (J T Jodkowski) Predicting and Understanding the Signs of One- and Two-Bond Spin-Spin Coupling Constants across X-H-Y Hydrogen Bonds (J E Del Bene & J Elguero) Towards the Elucidation of the Activation of Cisplatin in Anticancer Treatment (J V Burda et al.).

Electronic properties, hydrogen bonding, stacking, and cation binding of DNA and RNA bases.

Abstract: This review summarizes results concerning molecular interactions of nucleic acid bases as revealed by advanced ab initio quantum chemical (QM) calculations published in last few years. We first explain advantages and limitations of modern QM calculations of nucleobases and provide a brief history of this still rather new field. Then we provide an overview of key electronic properties of standard and selected modified nucleobases, such as their charge distributions, dipole moments, polarizabilities, proton affinities, tautomeric equilibria, and amino group hybridization. Then we continue with hydrogen bonding of nucleobases, by analyzing energetics of standard base pairs, mismatched base pairs, thio-base pairs, and others. After this, the nature of aromatic stacking interactions is explained. Also, nonclassical interactions in nucleic acids such as interstrand bifurcated hydrogen bonds, interstrand close amino group contacts, C—H … O interbase contacts, sugar–base stacking, intrinsically nonplanar base pairs, out-of-plane hydrogen bonds, and amino–acceptor interactions are commented on. Finally, we overview recent calculations on interactions between nucleic acid bases and metal cations. These studies deal with effects of cation binding on the strength of base pairs, analysis of specific differences among cations, such as the difference between zinc and magnesium, the influence of metalation on protonation and tautomeric equlibria of bases, and cation–π interactions involving nucleobases. In this review, we do not provide methodological details, as these can be found in our preceding reviews. The interrelation between advanced QM approaches and classical molecular dynamics simulations is briefly discussed. © 2002 Wiley Periodicals, Inc. Biopoly (Nucleic Acid Sci) 61: 3–31, 2002; DOI 10.1002/bip.10048

Cooperativity in hydrogen-bonded interactions: ab initio and "atoms in molecules" analyses.

Abstract: The H2CO···(HF)n (n = 1, ..., 9) complexes were investigated using the MP2 method and the following basis sets: 6-311++G(d,p), aug-cc-pVDZ and aug-cc-pVTZ. It was found that the cooperativity effect enhances significantly the F−H···O hydrogen bond; in some of cases one can detect the covalent nature of hydrogen bonding. To deepen the nature of the interactions investigated, the scheme of decomposition of the interaction energy was applied; for stronger H-bonds where the coopearativity is more important, the delocalization energy term increases. The ratio of delocalization energy to electrostatic energy increases for stronger hydrogen bonds where the proton···acceptor distance is shorter. The Bader theory was also applied, and it was found that for stronger H-bonds the electronic energy density at the proton···acceptor bond critical point is negative and may be attributed to the partly covalent interaction.

Spontaneous DNA Mutations Induced by Proton Transfer in the Guanine·Cytosine Base Pairs: An Energetic Perspective

Abstract: The energetic provisions for Lowdin's DNA mutational mechanism (Lowdin, P. O. Rev. Mod. Phys. 1963, 35, 724) of the formation of substitution DNA mutations were investigated for the guanine·cytosine Watson−Crick base pair. The structures studied involve the canonical base pair (GC1), rare base-pair tautomers that are formed from GC1 by the antiparallel simultaneous transfer of two protons in hydrogen bonds, and ion-pair structures that are formed by the transfer of a single proton. The geometries of these complexes were optimized by ab initio Hartree−Fock (HF) calculations using the 6-31G* basis set. At the same level, harmonic vibrational frequencies were determined. Nonplanar geometries featuring considerable propeller-twist angles and a pyramidal guanine amino group were found for base pairs involving the guanine anion and 6-hydroxyguanine. The relative stabilities and dissociation energies of the base pairs were determined at the higher MP2/6-31G**//HF/6-31G* level of theory. These methods were also u...

Properties of the C−H···H Dihydrogen Bond: An ab Initio and Topological Analysis

Abstract: The dihydrogen-bonded complexes of methane and its fluoro and chloro derivatives with lithium hydride are analyzed using ab initio methods as well as the Bader theory. All calculations were performed using Pople's basis sets (6-311++G(d,p), 6-311++G(2df,2pd), and 6-311++G(3df,3pd)) and the Dunning bases (aug-cc-pVDZ and aug-cc-pVTZ) within the MP2 method. The results of the calculations show that the binding energy for the analyzed complexes increases with the increase of the number of fluoro or chloro substituents, up to ∼7 kcal/mol. In the same order there is an increase of the electrostatic energy term, showing that for the CF3H···HLi complex the dihydrogen bond interaction is similar in nature as for the water dimer where a conventional O−H···O hydrogen bond exists, while for the CCl3H···HLi dimer the exchange energy term outweighs the electrostatic energy. Hence, the other attractive energy terms are important. A topological analysis based on the Bader theory supports the results of the ab initio cal...

The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: two new functionals and systematic testing of four M06-class functionals and 12 other functionals

Abstract: We present two new hybrid meta exchange- correlation functionals, called M06 and M06-2X. The M06 functional is parametrized including both transition metals and nonmetals, whereas the M06-2X functional is a high-nonlocality functional with double the amount of nonlocal exchange (2X), and it is parametrized only for nonmetals.The functionals, along with the previously published M06-L local functional and the M06-HF full-Hartree–Fock functionals, constitute the M06 suite of complementary functionals. We assess these four functionals by comparing their performance to that of 12 other functionals and Hartree–Fock theory for 403 energetic data in 29 diverse databases, including ten databases for thermochemistry, four databases for kinetics, eight databases for noncovalent interactions, three databases for transition metal bonding, one database for metal atom excitation energies, and three databases for molecular excitation energies. We also illustrate the performance of these 17 methods for three databases containing 40 bond lengths and for databases containing 38 vibrational frequencies and 15 vibrational zero point energies. We recommend the M06-2X functional for applications involving main-group thermochemistry, kinetics, noncovalent interactions, and electronic excitation energies to valence and Rydberg states. We recommend the M06 functional for application in organometallic and inorganometallic chemistry and for noncovalent interactions.

Quantum mechanical continuum solvation models.

Abstract: 6.2.2. Definition of Effective Properties 3064 6.3. Response Properties to Magnetic Fields 3066 6.3.1. Nuclear Shielding 3066 6.3.2. Indirect Spin−Spin Coupling 3067 6.3.3. EPR Parameters 3068 6.4. Properties of Chiral Systems 3069 6.4.1. Electronic Circular Dichroism (ECD) 3069 6.4.2. Optical Rotation (OR) 3069 6.4.3. VCD and VROA 3070 7. Continuum and Discrete Models 3071 7.1. Continuum Methods within MD and MC Simulations 3072

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

A Chemist's Guide to Density Functional Theory

Abstract: "Chemists familiar with conventional quantum mechanics will applaud and benefit greatly from this particularly instructive, thorough and clearly written exposition of density functional theory: its basis, concepts, terms, implementation, and performance in diverse applications. Users of DFT for structure, energy, and molecular property computations, as well as reaction mechanism studies, are guided to the optimum choices of the most effective methods. Well done!" Paul von RaguE Schleyer "A conspicuous hole in the computational chemist's library is nicely filled by this book, which provides a wide-ranging and pragmatic view of the subject.[...It] should justifiably become the favorite text on the subject for practioneers who aim to use DFT to solve chemical problems." J. F. Stanton, J. Am. Chem. Soc. "The authors' aim is to guide the chemist through basic theoretical and related technical aspects of DFT at an easy-to-understand theoretical level. They succeed admirably." P. C. H. Mitchell, Appl. Organomet. Chem. "The authors have done an excellent service to the chemical community. [...] A Chemist's Guide to Density Functional Theory is exactly what the title suggests. It should be an invaluable source of insight and knowledge for many chemists using DFT approaches to solve chemical problems." M. Kaupp, Angew. Chem.

Luminescent metal–organic frameworks for chemical sensing and explosive detection

Abstract: Metal–organic frameworks (MOFs) are a unique class of crystalline solids comprised of metal cations (or metal clusters) and organic ligands that have shown promise for a wide variety of applications Over the past 15 years, research and development of these materials have become one of the most intensely and extensively pursued areas A very interesting and well-investigated topic is their optical emission properties and related applications Several reviews have provided a comprehensive overview covering many aspects of the subject up to 2011 This review intends to provide an update of work published since then and focuses on the photoluminescence (PL) properties of MOFs and their possible utility in chemical and biological sensing and detection The spectrum of this review includes the origin of luminescence in MOFs, the advantages of luminescent MOF (LMOF) based sensors, general strategies in designing sensory materials, and examples of various applications in sensing and detection