DOCSLIB.ORG

Intermolecular Interactions from a Natural Bond Orbital, Donor-Acceptor Viewpoint

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Chem. Rev. 1988, 88, 899-926 899 Intermolecular Interactions from a Natural Bond Orbital, Donor-Acceptor Viewpoint ALAN E. REED‘ Instltul fur Organische Chemie der Universltat Erlangen-Nurnberg, Henkestrasse 42, 8520 Erlangen, Federal Republic of Germany LARRY A. CURTISS” Chemical Technology Division/Meterials Science and Technology Program, Argonne National Laboratoty, Argonne, Illinois 60439 FRANK WEINHOLD” Theoretical Chemlshy Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 Received November 10, 1987 (Revised Manuscript Received February 16, 1988) Contents D. Chemisorption 917 E. Relationships between Inter- and 918 I. Introduction 899 Intramolecular Interactions 11. Natural Bond Orbital Analysis 902 IV. Relationship of Donor-Acceptor and 919 A. Occupancy-Weighted Symmetric 902 Electrostatic Models Orthogonalization A. Historical Overview 919 8. Natural Orbitals and the One-Particle 903 B. Relationship to Kitaura-Morokuma Analysis 920 Density Matrix C. Semiempirical Potential Functions 92 1 C. Atomic Eigenvectors: Natural Atomic 904 V. Concluding Remarks 922 Orbitals and Natural Population Analysis D. Bond Eigenvectors: Natural Hybrids and 904 Natural Bond Orbitals E. Natural Localized Molecular Orbitals 905 1. Introdud/on F. Hyperconjugative Interactions in NBO 906 The past 15 years has witnessed a golden age of Analysis discovery in the realm of “van der Waals chemistry”. II I. Intermolecular Donor-Acceptor Models Based 906 The vm der wads bonding regimelies at the interface on NBO Analysis between two well-studied interaction types: the A. H-Bonded Neutral Complexes 906 short-range, strong (chemical) interactions of covalent 1. Water Dimer 906 type, and-the long-range, weak (physical) interactions 2. OC.-HF and COv-HF 908 of dispersion and multipole type. It was therefore surprising to discover that this borderline region gives Complexes of NO and HF 909 3. rise to species whose structural and energetic patterns 4. Of a Large Series Of H-Bond 910 are distinctivelv novel. As exDerimental nozzle beam14 Complexes and ab initio ~omp~tational*studies~*~have combined 5. Cooperativity in H-Bonding 911 to reveal the rich architectural patterns of van der 6. Hydrophobic Interactions 912 Waals bonding, efforts have been made to extend the 7. Other Tooics 913 elementary principles of valence theory to encompass B. Non-H-Bonded Neutral Complexes 914 such bonds within a general conceptual framework of covalent and noncovalent interactions. The present 1. Survey of a Large Series of 914 article reviews progress that has been made toward this Non-H-Bonded Complexes goal by the method of natural bond orbital analysis, 2. Competition between H-Bonded and 914 particularly for H-bonded and other strongly bound van Non-H-Bonded Structures der Waals complexes. 3. Complexes of Rare Gases with Be0 915 Natural bond orbital (NBO) analysis originated’ as C. Ion-Molecule Complexes and Contact Ion 915 a technique for studying hybridization and covalency Pairs effects in polyatomic wave functions, based on local 1. Anion-Water Complexes 915 block eigenvectors of the one-particle density matrix (see section 11). NBOs were conceived as a “chemist’s 2. Cation-Water Complexes 916 basis set” that would correspond closely to the picture 3. Bifluoride Ion 916 of localized bonds and lone pairs as basic units of mo- 4. “Salt” Isomer of Carbon Tetrachloride 916 lecular structure. The NBO for a localized u bond uAB 5. Ground and Excited States of (CO),’ 916 between atoms A and B is formed from directed or- 0009-2665/88/0788-0899$06.50/0 @ 1988 American Chemical Society 900 Chemical Reviews. 1988, VOI. 88, NO. 6 Reed et 81. Alan E. Reed was born in Chicago, IL, in 1958 and received his B.S. degree In chemistry from the University of Illinois at Champ- Frank A. Welnhokl was bwn in Scottsbluff. NE. in 1941. He SMied aign-Urbana In 1980, having carried out experimental research chemistry as an undergraduate at the University of Colorado. both there and at the University of Chicago. He received his h.D. Boulder (1958-1962), as a Fulbright Scholar at the Universitat in physical chemistry from the University of Wisconsin at Madison FreiburglBreisgau in Germany (1962-1963), and as a graduate in 1985. working with Prof. Frank Weinhold, a part of this work student (under Prof. E. B. Wilson, Jr.) at HaNard University. where being carried out with Dr. Larry Curtiss at Argonne National Lab- he received the Ph.D. degree in physical chemistry in 1967. His oratory. Curremly. he is doing postdoctoral research with Prof. Paul postdoctoral studies were at Oxford (with Prof. C. A. Coulson) and von Ragu6 Schleyer at Erlangen. West Germany. His scientific Berkeley (Miller Fellow). He has taught at Stanford University and interests concern the rich range of diversity and possibility in the University of Wisconsin, Madison, where he is currently Pro- chemical Structure and bonding, from solid state to biochemical fessor of Chemistry and Director of the Theoretical Chemistry systems, and have focused primarily on the theoretical description Instiiute. His principal research interests include upper and lower of inter- and intramolecular bonding involving elements H to Ar, bounds for quantum mechanical properties, metric geometry of including studies of hypervalency. hyperconjugation. and the equilibrium thermodynamics. and natural bond orbital studies of anomeric effect. covalent and noncovalent interactions. atomic and bond properties. Ab initio wave functions transformed to NBO form are found to be in good agreement with Lewis structure concepts and with the basic Pauling-Slater-Coulson picture” of bond hy- bridization and polarization. The filled NBOs um of the “natural Lewis structure” me therefore well adapted to describing covalency effects in molecules. However, the general transformation to NBOs also leads to orbitals that are unoccupied in the formal Lewis structure and that may thus be used to describe non- covalency effects. The most important of these are the antibonds u*ml* Larry A. Curtiss was born in Madison. WI. in 1947 and received his B.S. degree in chemistry from the University of Wisconsin in U*AB= CBhA - CAhB Ob) 1969. He received his Ph.D. degree in physical chemistry in 1973 wofking with Professw John A. Popb. He tbn spent about 2 years which arise from the same set of atomic valence-shell as a httelle lnstiute Fellow at Banelle Memurial Institute (wofking hybrids that unite to form the bond functions um, eq with Professor C. W. Kern) in Columbus. OH. In 1976 he joined la. The antibonds represent unused valence-shell ca- the Chemical Technology Division at Argonne National Laboratory. His research interesls include theoretical studies of van der Waals pacity, spanning portions of the atomic valence space complexes. ordered and ionic solutions, zeolies, hetereogeneous that are formally unsaturated by covalent bond for- charge-transfer reactions, and small molecules and their cations. mation. Small occupancies of these antibonds corre- In addition, he has been involved in experimental studies of gas- spond, in Hartree-Fock theory, to irreducible depar- phase association reactions. tures from the idealized Lewis picture and thus to small noncovalent corrections to the picture of localized co- valent bonds. thonormal hybrids hA, hB [natural hybrid orbitals The energy associated with the antibonds can be (NHOs)l numerically assessed by deleting these orbitals from the basis set and recalculatine the t~talenem to determine um = cAhA+ cBhB (la) the associated variationai energy 1oweri;g. In this way and the natural hybrids in turn are composed from a one obtains a decomposition of the total energy E into set of effective valence-shell atomic orbitals [natural components associated with covalent (Eoo= Em)and atomic orbitals (NAOS)],~*~optimized for the chosen noncovalent (Eo8 = Enon.Le+)contributions wave function. A distinguishingfeature of such natural E = E,,,, E., (2) localized functions (analogous to classic “natural + orbitals” in the Lowdin delocalized senselo) is the si- NBO decompositions of this form have now been ob- multaneous requirement of orthonormality and maxi- tained for a large number of closed-shell and open- mum occupancy, leading to compact expressions for shelP molecular species. In equations such as (1) and Donor-Acceptor Interactlons Chemical Reviews, 1988, Vol. 88, No. 6 901 TABLE I. NBO Energy Decompositions for Selected E2 /- \ Molecules (RHF/6-31G* Level, Pople-Gordon Idealized \ Geometry), Showing the Covalent Contribution E(Lewis) = I I \ E,,, the Noncovalent Contribution E(non-Lewis) = E,,., -%* and the Percentage Contribution % E(Lewis) Associated I I with the Natural Lewis Structure” I I I I molecule E(Lewis) E(non-Lewis) % E(Lewis) I I BH, -26.384470 -0.005434 99.979 I I CH; -40.187329 -0.007732 99.981 NH3 -56.180217 -0.003527 99.994 HZO -76.007041 -0.002827 99.996 HF -100.001908 -0.000900 99.999 A1Ha -243.570589 -0.045162 99.982 SiH, -291.192327 -0.032763 99.989 Figure 1. Perturbative donor-acceptor interaction, involving a PH3 -342.410798 -0.019140 99.994 filled orbital u and an unfilled orbital u*. H2S -398.652368 -0.007483 99.998 HCl -460.056952 -0.002661 99.999 CFaH -336.469129 -0.295778 99.912 MOs are strictly unoccupied and thus play no role in C2H6 -79.170183 -0.057562 99.927 the wave function or any observable property, whereas C2HI -77.953649 -0.076717 99.902 the antibonds (u*-) generally exhibit nonzero occu- CzHz -76.728306 -0.089021 99.884 HZCO -113.762634 -0.101071 99.911 pancies, and their contibutions lead to definite energy c&6 -230.107441 -0.594436 99.742 lowerings and changes in the form of the wave function. The role of antibonds can be seen by transforming the ONote the effect of vicinal u - u* interactions (molecules 11-15 of the list) and of aromatic “resonance” (C6He)in reducing the occupied canonical MOs to localized molecular orbital dominance of a sinele Lewis structure.
Recommended publications
  • Periodic Table and Bonding Notes 2

    Periodic Table and Bonding Notes 2

    Periodic Table and Bonding 1. Handout: Periodic Table and Bonding Notes 2. Periodic Properties and the Development of the Periodic Table 1. The first periodic table was arranged by Dimitri Mendeleev in 1869. 1. He was a professor of Chemistry. at the University of St. Petersburg in Russia and was confronted with the problem of how to teach about the various elements known at that time. He decided to organized the elements by arranging them into groups that reacted similarly. 2. He also noticed that various properties would repeat "periodically" so he arranged a table of elements order of atomic mass such that properties would change regularly if you moved across a row while maintaining groups with similar chemical properties in a column. 3. Go to: http://www.periodic.lanl.gov/mendeleev.htm to see a version of Mendeleev's first table. 2. Groups with similar properties 1. All the elements in a group (or column) are called families. 2. Group 8: The Noble Gases, don't react with other elements. 3. Group 1: The Alkali Earth Metals, all react with water in the following manner 2 Li + H2O ---> H2 + 2 LiOH 2 Na + H2O ---> H2 + 2 NaOH ... 2 Fr + H2O ---> H2 + 2 FrOH page 1 4. These are just a few examples of how Mendeleev organized the columns or families. 3. Periodic Properties 1. As you move across a row various properties change regularly click on the images below to see a visualization of the various properties. All of these images are from www.webelements.com, one of the best periodic table sites on the web.
  • Symmetry of Three-Center, Four-Electron Bonds†‡

    Symmetry of Three-Center, Four-Electron Bonds†‡

    Chemical Science EDGE ARTICLE View Article Online View Journal | View Issue Symmetry of three-center, four-electron bonds†‡ b a c Cite this: Chem. Sci., 2020, 11,7979 Ann Christin Reiersølmoen, § Stefano Battaglia, § Sigurd Øien-Ødegaard, Arvind Kumar Gupta, d Anne Fiksdahl,b Roland Lindh a and Mate Erdelyi *a All publication charges for this article ´ ´ ´ have been paid for by the Royal Society of Chemistry Three-center, four-electron bonds provide unusually strong interactions; however, their nature remains ununderstood. Investigations of the strength, symmetry and the covalent versus electrostatic character of three-center hydrogen bonds have vastly contributed to the understanding of chemical bonding, whereas the assessments of the analogous three-center halogen, chalcogen, tetrel and metallic s^-type long bonding are still lagging behind. Herein, we disclose the X-ray crystallographic, NMR spectroscopic and computational investigation of three-center, four-electron [D–X–D]+ bonding for a variety of cations (X+ ¼ H+,Li+,Na+,F+,Cl+,Br+,I+,Ag+ and Au+) using a benchmark bidentate model system. Formation of a three-center bond, [D–X–D]+ is accompanied by an at least 30% shortening of the D–X Received 11th April 2020 bonds. We introduce a numerical index that correlates symmetry to the ionic size and the electron Accepted 19th June 2020 affinity of the central cation, X+. Providing an improved understanding of the fundamental factors DOI: 10.1039/d0sc02076a Creative Commons Attribution 3.0 Unported Licence. determining bond symmetry on a comprehensive level is expected to facilitate future developments and rsc.li/chemical-science applications of secondary bonding and hypervalent chemistry.
  • Physics of Soft Colloidal Matter

    Physics of Soft Colloidal Matter

    Physics of Soft Colloidal Matter {Interaction potentials and colloidal stability{ Peter Lang Spring term 2017 Contents 1 Interactions 3 1.1 Molecular Interactions . 3 1.1.1 Interaction between a charge and a dipole . 3 1.1.2 Dipole{Dipole Interactions . 7 1.1.3 Induced Dipolar Interactions . 8 1.1.4 Dispersion Interactions . 9 1.1.5 Van der Waals Interactions . 13 1.2 Van der Waals Interaction Between Colloidal Bodies . 14 1.2.1 Interaction between a single molecule and a wall . 14 1.2.2 Interaction between two planar walls . 15 1.2.3 Interaction between a sphere and a wall . 18 1.2.4 Interaction between two spheres . 20 1.2.5 The Hamaker constant and the Lifshitz continuum theory . 21 1.3 Repulsive interaction and Colloidal Stability . 23 1.3.1 Electrostatic Repulsion in the Debye{H¨uckel Limit . 24 1 Contents 1.3.2 Addition of Van der Waals and Electrostatic Potential: The DLVO Theory . 37 1.4 Non DLVO Interactions . 40 1.4.1 Depletion interaction . 40 1.5 Exercises . 49 1.6 Solutions to Exercises . 52 2 1 Interactions 1.1 Molecular Interactions As the interaction energy between large bodies like colloidal particles is composed of the interaction between their atomic or molecular constituents we will first briefly discuss interactions between molecular • a charge and a permanent dipole • permanent dipoles • induced dipoles • fluctuating dipoles 1.1.1 Interaction between a charge and a dipole Fixed Orientation According to Figure 1.1, a point particle with charge Q = Ze (Z is the number of elementary charges e)at position A shall interact with a permanent dipole at distance 3 1 Interactions C q+ Q=ze r q A l/2 q- B Figure 1.1: For the calculation of the interaction between a point charge and a permanent dipole r with the length l and two partial charges of equal magnitude but opposite sign.
  • Triazole, and Coumarin Bearing 6,8-Dimethyl

    Triazole, and Coumarin Bearing 6,8-Dimethyl

    Article Volume 12, Issue 1, 2022, 809 - 823 https://doi.org/10.33263/BRIAC121.809823 Synthesis, Molecular Characterization, Biological and Computational Studies of New Molecule Contain 1,2,4- Triazole, and Coumarin Bearing 6,8-Dimethyl Pelin Koparir 1,* , Kamuran Sarac 2 , Rebaz Anwar Omar 3,4,* 1 Forensic Medicine Institute, Department of Chemistry, 44100 Malatya, Turkey; [email protected] (P.K.); 2 Bitlis Eren University, Faculty of Art and Sciences, Department of Chemistry, 13000 Bitlis, Turkey; [email protected] (K.S.); 3 Department of Chemistry, Faculty of Science & Health, Koya University, Koya KOY45, Kurdistan Region – F.R. Iraq 4 Fırat University, Faculty of Sciences, Department of Chemistry, 23000 Elazığ, Turkey; [email protected] (R.O.); * Correspondence: [email protected] (P.K.); [email protected] (R.O.); Scopus Author ID 57222539130 Received: 22.02.2021; Revised: 5.04.2021; Accepted: 9.04.2021; Published: 26.04.2021 Abstract: Synthesis 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazol-3-yl)thio)methyl)-6,8-dimethyl- coumarin and spectral analysis is carried out using the FT-IR and NMR with the help of quantum chemical calculation by DFT/6-311(d,p). The molecular electrostatic potentials and frontier molecular orbitals of the title compound were carried out at the B3LYP/6-311G(d,p) level of theory. Antimicrobial, antioxidant activity, and In vitro cytotoxic for cell lines were observed. The result shows that the theoretical vibrational frequencies, 1H-NMR and 13C-NMR chemical shift, agree with experimental data. In vitro studies showed that antimicrobial activity was weak, particularly against bacteria such as E.
  • คม 331 เคมีอนินทรีย์1 ปีการศึกษา 1-2561

    คม 331 เคมีอนินทรีย์1 ปีการศึกษา 1-2561

    Chemical Bondings คม 331 เคมีอนินทรีย์ 1 ปีการศึกษา 1-2561 1. บทน า พันธะเคมี (Chemical Bondings) • พันธะเคมี → แรงดึงดูดระหว่างอะตอม โมเลกุล หรือไอออน ท าให้มีความเสถียรเพิ่มขึ้นกว่าเมื่อ อยู่เป็นอะตอม โมเลกุล หรือไอออนเดี่ยวๆ - หัวข้อ • พันธะเคมีเกิดจากการใช้อิเล็กตรอนวงนอก (valence e ) ได้แก่ (1) การให้-รับ valence e- หรือ (2) การใช้ valence e- ร่วมกันระหว่างคู่ที่เกิดพันธะ 1. บทน า 5. เรโซแนนซ์ • พันธะระหว่างอะตอมหรือไอออน มีความแข็งแรงมากกว่าพันธะระหว่างโมเลกุล 2. ประเภทของพันธะเคมี 6. ประจุฟอร์มอล • พันธะเคมี เป็นแรงดึงดูดที่แข็งแรงกว่าแรงทางเคมี 3. แรงระหว่างโมเลกุล 7. กฎ 18 อิเล็กตรอน • พันธะเคมีระหว่างอะตอมหรือไอออน ได้แก่ พันธะไอออนิก พันธะโควาเลนต์ และพันธะโลหะ 4. ทฤษฎีพันธะเคมี 8. พันธะ 3 อะตอม 2 อิเล็กตรอน → เกี่ยวข้องกับสมบัติทางเคมีหรือปฏิกิริยาเคมีของธาตุหรือสารประกอบ • พันธะระหว่างโมเลกุล ได้แก่ พันธะไฮโดรเจนและแรงแวนเดอร์วาลส์ → เกี่ยวข้องกับสมบัติ ทางกายภาพของสารมากกว่าสมบัติทางเคมี เนื้อหาบรรยาย รายวิชา คม 331 เคมีอนินทรีย์ 1 เนื้อหาบรรยาย รายวิชา คม 331 เคมีอนินทรีย์ 1 http://www.chemistry.mju.ac.th/wtms_documentAdminPage.aspx?bID=4093 อ.ดร.เพชรลดา กันทาดี อ.ดร.เพชรลดา กันทาดี 2 พันธะเคมี อาจารย์ ดร.เพชรลดา กันทาดี 1 Chemical Bondings Chemical Bondings 1. บทน า 2. ประเภทของพันธะเคมี • พันธะเคมีระหว่างอะตอม → ระยะระหว่างสองอะตอมจะต้องไม่ไกลเกินไปจนนิวเคลียสของ 1. พันธะไอออนิก (Ionic bond) สองอะตอมไม่ดึงดูดกัน และไม่ใกล้เกินไปจนเกิดแรงผลักระหว่างอิเล็กตรอนของสองนิวเคลียส - บางครั้งเรียกว่า พันธะอิเล็กโทรเวเลนซ์ (electrovalence bond) หรือพันธะ → ระยะที่เหมาะสมนี้ เรียกว่า ความยาวพันธะ ไฟฟ้าสถิตย์ (electrostatic bond)
  • Competition of Van Der Waals and Chemical Forces on Gold–Sulfur Surfaces and Nanoparticles

    Competition of Van Der Waals and Chemical Forces on Gold–Sulfur Surfaces and Nanoparticles

    Downloaded from orbit.dtu.dk on: Oct 01, 2021 Competition of van der Waals and chemical forces on gold–sulfur surfaces and nanoparticles Reimers, Jeffrey R.; Ford, Michael J.; Marcuccio, Sebastian M.; Ulstrup, Jens; Hush, Noel S. Published in: Nature Reviews. Chemistry Link to article, DOI: 10.1038/s41570-0017 Publication date: 2017 Document Version Peer reviewed version Link back to DTU Orbit Citation (APA): Reimers, J. R., Ford, M. J., Marcuccio, S. M., Ulstrup, J., & Hush, N. S. (2017). Competition of van der Waals and chemical forces on gold–sulfur surfaces and nanoparticles. Nature Reviews. Chemistry, 1(2), [0017]. https://doi.org/10.1038/s41570-0017 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. REVIEW ARTICLE: Competition of van der Waals and chemical forces on gold-sulfur surfaces and nanoparticles Jeffrey R. Reimers1,2, Michael J. Ford2, Sebastian M. Marcuccio3,4, Jens Ulstrup5, and Noel S.
  • Title: Molecular Structure Elucidation with Charge-State Control

    Title: Molecular Structure Elucidation with Charge-State Control

    This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on Vol. 365, Issue 6449, page 142, 12 July 2019, DOI: 10.1126/science.aax5895. Title: Molecular structure elucidation with charge-state control Authors: Shadi Fatayer1*, Florian Albrecht1, Yunlong Zhang2, Darius Urbonas1, Diego Peña3, Nikolaj Moll1, Leo Gross1* Affiliations: 1IBM Research – Zurich. 2ExxonMobil Research and Engineering Company. 3Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. *Correspondence to: [email protected], [email protected] Abstract: The charge state of a molecule governs its physicochemical properties, such as conformation, reactivity and aromaticity, with implications for on-surface synthesis, catalysis, photo conversion and applications in molecular electronics. On insulating, multilayer NaCl films we control the charge state of organic molecules and resolve their structures in neutral, cationic, anionic and dianionic states by atomic force microscopy, obtaining atomic resolution and bond-order discrimination using CO functionalized tips. We detect changes in conformation, adsorption geometry and bond-order relations for azobenzene, tetracyanoquinodimethane and pentacene in multiple charge states. Moreover, for porphine we investigate the charge-state-dependent change of aromaticity and conjugation pathway in the macrocycle. This work opens the way to studying chemical-structural changes of individual molecules for a wide range of charge states. One Sentence Summary: Adsorption properties and bond-order relations of single molecules in multiple oxidation states are resolved by atomic force microscopy.
  • Inorganic Chemistry for Dummies® Published by John Wiley & Sons, Inc

    Inorganic Chemistry for Dummies® Published by John Wiley & Sons, Inc

    Inorganic Chemistry Inorganic Chemistry by Michael L. Matson and Alvin W. Orbaek Inorganic Chemistry For Dummies® Published by John Wiley & Sons, Inc. 111 River St. Hoboken, NJ 07030-5774 www.wiley.com Copyright © 2013 by John Wiley & Sons, Inc., Hoboken, New Jersey Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permis- sion of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley. com/go/permissions. Trademarks: Wiley, the Wiley logo, For Dummies, the Dummies Man logo, A Reference for the Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission. All other trade- marks are the property of their respective owners. John Wiley & Sons, Inc., is not associated with any product or vendor mentioned in this book.
  • Learn Chemistry in an Hour

    Learn Chemistry in an Hour

    Fascinating Education Script Learn Chemistry in an Hour Lesson: Learn Chemistry in an Hour Slide 1: Introduction Slide Slide 2: Why Chemistry first? To my way of thinking, chemistry should be taught before biology, physics, and even earth science. Biology is in large part chemistry of the cell. The forces of physics stem from the forces between protons, neutrons, and electrons. Earth science makes a lot more sense once students understand how elements combined to form the earth’s crust, and how the chemical properties of each geologic structure govern the forces within the earth’s crust. In the next hour or so we will cover the fundamental key to chemistry, which is this: there are about 100 different types of atoms in the world. Atoms bond to other atoms to make molecules, but they only use four different ways to bond to each other. Each of the four bonds produces a characteristic property in the molecule. So, by understanding the four bonds, you understand why water at room temperature is liquid, why oil and water don’t mix, why metals are shiny, and so on. The rest of chemistry that we’ll touch on is how to measure the number, mass, volume, pressure, and temperature of molecules, what happens when you change one of these variables, and how molecules swap atoms in chemical reactions. If you’re a parent, this lesson will enable you to follow -- and even guide -- your child’s progress through chemistry. If you’re a student, the next hour will give you a heads up and a head start.
  • Introduction to Organic Compounds

    Introduction to Organic Compounds

    Chapter 2 Introduction to organic compounds Nomenclature Physical properties Conformation Organic compounds Ch 2 #2 in Organic Chemistry 1 hydrocarbons [RH] alkanes alkenes alkynes alkyl halides [RX] ethers [ROR’] alcohols [ROH] amines [RNH2] in Org Chem 2 aromatic comp’ds carbonyl comp’ds Alkanes Ch 2 #3 saturated hydrocarbons saturated ~ all single bonds; no multiple bond [= or ≡] hydrocarbon [HC] ~ contains only C and H <cf> carbohydrate homologs general formula ~ CnH2n+2 differs by CH2 (methylene) paraffins non-polar, hydrophobic Ch 2 #4 Constitutional isomers Ch 2 #5 isomers [異性質體] same composition, different structure (and shape) constitutional isomer = structural isomer = skeletal isomer two or more compounds with the same molecular formula [composition] different structural formula [connectivity] e.g. C H O 2 6 H H H H H C C O H H C O C H H H H H eg C4H10 Constitutional isomers in alkanes Ch 2 #6 straight-chain vs branched alkanes ‘iso’ ~ C bonded to 1 H and 2 methyls [CH3] neopentane Ch 2 #7 # of possible isomers as # of atoms C20H42 has 366,319 isomers! drawn? calculated? nomenclature ~ naming common name = trivial name systematic name = IUPAC name Alkyl substituents [groups] Ch 2 #8 R ~ alkyl R with =, alkenyl; R with ≡, alkynyl RH is alkane, and If R covers alkyl, alkenyl, and alkynyl, RH is HC. Isomeric alkyls Ch 2 #9 propyl n ~ normal, commonly omitted (n-)propyl ~ CH3CH2CH2- isopropyl ~ (CH3)2CH- butyl CH3 sec- (or s-) tert- or t- Degree of substitution of carbon CH3 H3C CH3 H3C CH C C C CH3 primary [1°] H H carbon 2 2 secondary [2°] tertiary [3°] quaternary [4°] carbon carbon carbon Ch 2 #10 primary hydrogen? pentyl pentyl isopentyl tert-pentyl IUPAC name perferred sec-? sec-? neopentyl Ch 2 #11 commonly used alkyl groups OH isobutyl alcohol NH2 sec-butylamine (Systematic) nomenclature of alkanesCh 2 #12 1.
  • Structures and Reactivity of Transition-Metal Compounds

    Structures and Reactivity of Transition-Metal Compounds

    STRUCTURES AND REACTIVITY OF TRANSITION-METAL COMPOUNDS FEATURING METAL-LIGAND MULTIPLE BONDS A Dissertation by ZHENGGANG XU Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, Michael B. Hall Committee Members, Roland E. Allen Robert R. Lucchese Simon W. North Head of Department, David H. Russell August 2014 Major Subject: Chemistry Copyright 2014 Zhenggang Xu ABSTRACT This dissertation presents the results from density functional theory (DFT) calculations on three major projects I have been working on over the past several years. The first system is focused on the structure and reactivity of a novel osmium silylyne compounds featuring an Os≡Si triple bond. NMR simulation confirmed the existence of this compounds and bonding analysis like NBO and ETS-NOCV proved its triple bond character. The structures of the [2+2] cyclo-addition product from silylyne and other small molecules (PhC≡CPh and P≡CtBu) were also determined from possible isomers by energetic results and NMR simulations. The cycloaddition reactions were found to be under kinetic control and steric effects should be a major reason for that. Furthermore, the geometric and electronic structures of the osmium silylyne analogues (M≡E, M = Ru and Os; E = Si, Ge and Sn) are studied computationally and their similarities and distinctions are discussed. Both the second and third systems are related to the formation of transition metal imido compound (M=NR). In the second system a cationic oxorhenium(V) complex reacts with a series of arylazides (N3Ar) to give cationic cis-rhenium(VII) oxo imido complexes.
  • Asian Journal of Chemistry Asian Journal of Chemistry

    Asian Journal of Chemistry Asian Journal of Chemistry

    Asian Journal of Chemistry; Vol. 28, No. 1 (2016), 116-120 ASIAN JOURNAL OF CHEMISTRY http://dx.doi.org/10.14233/ajchem.2016.19262 Theoretical Studies on Interaction Between CO2 Gas and Imidazolium-Type Organic Ionic Liquid Using DFT and Natural Bond Orbital Calculations 1,2,* SAIED M. SOLIMAN 1Department of Chemistry, Rabigh College of Science and Art, King Abdulaziz University, Jeddah, P.O. Box 344, Rabigh 21911, Saudi Arabia 2Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426 Ibrahimia, 21525 Alexandria, Egypt *Corresponding author: Tel: +966 565450752; E-mail: [email protected]; [email protected] Received: 20 April 2015; Accepted: 31 July 2015; Published online: 5 October 2015; AJC-17557 The interaction between 4,5-dibromo-1-butyl-3-methylimidazolium trifluoromethanesulfonate; [DBBIM][TFMSO3] ionic liquid and CO2 gas has been studied using DFT calculations. With the help of natural bond orbital (NBO) analyses, the second order perturbation energies of the most interacting natural bond orbitals and natural atomic charges have been predicted by the density functional theory (DFT) computations at the X3LYP/6-31++G(d,p) level of theory. The natural charge calculations showed that in the ionic liquid-CO2 system, the [DBBIM][TFMSO3] ionic liquid is the electron donor while CO2 gas is an electron acceptor. Further stabilization of the imidazolium ring π-system is produced due to the interaction of the CO2 gas with the ionic liquid. The polarization of the C–O and S1–O3 bonds are affected significantly by such interactions. The charge decomposition (CDA) analysis revealed the strong interactions between the [DBBIM]+ and – [TFMSO3] ions of the ionic liquid and the weak interaction between the ionic liquid and the CO2 gas.