Reaction Mechanism of Transition Metal Complexes
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Transition State Theory. I
MIT OpenCourseWare http://ocw.mit.edu 5.62 Physical Chemistry II Spring 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.62 Spring 2007 Lecture #33 Page 1 Transition State Theory. I. Transition State Theory = Activated Complex Theory = Absolute Rate Theory ‡ k H2 + F "! [H2F] !!" HF + H Assume equilibrium between reactants H2 + F and the transition state. [H F]‡ K‡ = 2 [H2 ][F] Treat the transition state as a molecule with structure that decays unimolecularly with rate constant k. d[HF] ‡ ‡ = k[H2F] = kK [H2 ][F] dt k has units of sec–1 (unimolecular decay). The motion along the reaction coordinate looks ‡ like an antisymmetric vibration of H2F , one-half cycle of this vibration. Therefore k can be approximated by the frequency of the antisymmetric vibration ν[sec–1] k ≈ ν ≡ frequency of antisymmetric vibration (bond formation and cleavage looks like antisymmetric vibration) d[HF] = νK‡ [H2] [F] dt ! ‡* $ d[HF] (q / N) 'E‡ /kT [ ] = ν # *H F &e [H2 ] F dt "#(q 2 N)(q / N)%& ! ‡ $ ‡ ‡* ‡ (q / N) ' q *' q *' g * ‡ K‡ = # trans &) rot ,) vib ,) 0 ,e-E kT H2 qH2 ) q*H2 , gH2 gF "# (qtrans N) %&( rot +( vib +( 0 0 + ‡ Reaction coordinate is antisymmetric vibrational mode of H2F . This vibration is fully excited (high T limit) because it leads to the cleavage of the H–H bond and the formation of the H–F bond. For a fully excited vibration hν kT The vibrational partition function for the antisymmetric mode is revised 4/24/08 3:50 PM 5.62 Spring 2007 Lecture #33 Page 2 1 kT q*asym = ' since e–hν/kT ≈ 1 – hν/kT vib 1! e!h" kT h! Note that this is an incredibly important simplification. -
Eyring Equation
Search Buy/Sell Used Reactors Glass microreactors Hydrogenation Reactor Buy Or Sell Used Reactors Here. Save Time Microreactors made of glass and lab High performance reactor technology Safe And Money Through IPPE! systems for chemical synthesis scale-up. Worldwide supply www.IPPE.com www.mikroglas.com www.biazzi.com Reactors & Calorimeters Induction Heating Reacting Flow Simulation Steam Calculator For Process R&D Laboratories Check Out Induction Heating Software & Mechanisms for Excel steam table add-in for water Automated & Manual Solutions From A Trusted Source. Chemical, Combustion & Materials and steam properties www.helgroup.com myewoss.biz Processes www.chemgoodies.com www.reactiondesign.com Eyring Equation Peter Keusch, University of Regensburg German version "If the Lord Almighty had consulted me before embarking upon the Creation, I should have recommended something simpler." Alphonso X, the Wise of Spain (1223-1284) "Everything should be made as simple as possible, but not simpler." Albert Einstein Both the Arrhenius and the Eyring equation describe the temperature dependence of reaction rate. Strictly speaking, the Arrhenius equation can be applied only to the kinetics of gas reactions. The Eyring equation is also used in the study of solution reactions and mixed phase reactions - all places where the simple collision model is not very helpful. The Arrhenius equation is founded on the empirical observation that rates of reactions increase with temperature. The Eyring equation is a theoretical construct, based on transition state model. The bimolecular reaction is considered by 'transition state theory'. According to the transition state model, the reactants are getting over into an unsteady intermediate state on the reaction pathway. -
Towards Transition Metal-Catalyzed Hydration of Olefins; Aquo Ions, And
Towards Transition Metal-Catalyzed Hydration of Olefins; Aquo Ions, and Pyridylphosphine-Platinurn and Palladium Complexes By YUNXIE B.Sc. Peking University, 1983 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Department of Chemistry) We accept this thesis as confirming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA July, 1990 © YUN XIE, 1990 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada DE-6 (2/88) ABSTRACT This thesis work resulted from an on-going project in this laboratory focusing on the hydration of olefins, using transition metal complexes as catalysts, with the ultimate aim of achieving catalytic asymmetric hydration, for example: (H02C)CH=CH(C02H) (H02C)CH2-CH(OH)(C02H) * (C = chiral carbon atom). 3+ Initially, the hydration of maleic to malic acid, catalyzed by Cr(H20)6 at 100°C in aqueous solution was studied, including the kinetic dependences on Cr3+, maleic acid and pH. A proposed mechanism involving 1:1 complexes of Cr3+ with the maleato and malato monoanions is consistent qualitatively with the kinetic data. -
Environmental Speciation and Monitoring Needs for Trace Metal -Contai Ni Ng Substances from Energy-Related Processes
STAND NATL iNST OF AU107 1=17^05 NBS 1>l PUBLICATIONS z CO NBS SPECIAL PUBLICATION * / Of U.S. DEPARTMENT OF COMMERCE / National Bureau of Standards -QC 100 .U57 NO. 618 1981 c. 2 NATIONAL BUREAU QF STANDARDS The National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system of physical and chemical and materials measurement; coordinates the system with measurement systems of other nations and furnishes essential services leading to accurate and uniform physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement, standards, and data on the properties of materials needed by industry, commerce, educational institutions, and Government; provides advisory and research services to other Government agencies; develops, produces, and distributes -
A Review on the Metal Complex of Nickel (II) Salicylhydroxamic Acid and Its Aniline Adduct
Adegoke AV, et al., J Transl Sci Res 2019, 2: 006 DOI: 10.24966/TSR-6899/100006 HSOA Journal of Translational Science and Research Review Article Introduction A Review on the Metal Complex Metal complexes are formed in biological systems, particularly of Nickel (II) Salicylhydroxamic between ligands and metal ions in dynamic equilibrium, with the free metal ion in a more or less aqueous environment [1]. All biologically Acid and its Aniline Adduct important metal ions can form complexes and the number of different chemical species which can be coordinated with these metal ions is very large. During the past few decades, a lot of scientist research 1 1 2 3 Adegoke AV *, Aliyu DH , Akefe IO and Nyan SE groups operated through specialization in the direction of drug dis- 1Department of Chemistry, Faculty of Science, University of Abuja, Nigeria covery, by studying the simplest species that use metal ions and re- searching them as whole compound; for example, they suggested the 2 Department of Physiology, Biochemistry and Pharmacology, Faculty of addition of metal ion to antibiotics to facilitate their spread through- Veterinary Medicine, University of Jos, Nigeria out the body [2]. The development of drug resistance as well as the 3Department of Chemistry, Faculty of Science, Kaduna State University, appearance of undesirable side effects of certain antibiotics has led to Nigeria the search of new antimicrobial agents with the goal to discover new chemical structures which overcome the above disadvantages. As a ligand with potential oxygen and nitrogen donors, hydroxamic acids are interesting and have gained special attention not only because of Abstract the structural chemistry of their coordination modes, but also because Metal complexes are fundamentally known to be engendered in of their importance in medical chemistry [3]. -
Answers to Selected Problems
Answers to Selected Problems Chapter 1 1.2. 0.55 A 1.3. +-y-.z- ++ y+, z+ t-t-y+,~+ -!-!y+.z+ *x+ lx+ t-x+ *s -ls i- s- 1- s+ -l s+ t- s+ BeO triplet CO singlet NO doublet 1.5. "Ionic bonds" using 6p electrons are stronger than those using 6s electrons (Pb2+2Br- p Pb4 +4Br-). "Covalent bonds" with 6s electrons are stronger than those with 6p electrons (PbMe4 > PbMe2)' The energy gap between 6p and 6s orbitals is larger than that for 2p and 2s orbitals. 1.6. SOl = Cda + b + c + d + e + f) S02 = C2(a + b - c - d + e +f) S03 = C3(a - b + c - d + e + f) 541 542 Answers to Selected Problems S04 = C4 (a + b + c + d - e +f) SOs = Cs(a + b - c - d - e +f) SOb = C6 (a - b - c + d - e + f) 1.9. B. c. D d. 0 1.10. There is no vibrational distortion of a homonuclear diatomic that can lower its symmetry. Chapter 2 2.2. Charge density qi = 1; n-bond order Pii = I. 2.3. Il.E = 1l.E,. + IlE,; 1l.E, = 2(1 - i 12) {J. 2.4. Second-order perturbations are not additive. In double union of even AHs, the second order terms are large and cannot be ignored. Chapter 3 3.1. 4 J -jill jm Answers to Selected Problems 543 3.2. a. Ii) I1E n = 2-=( 2 + --3) {J = 0.92{J " ,,/17.7 j17.7 I1Enp = 2 ( --~- + 1 ) {J = 1.28{J j17.7 )17.7 (ii) I1En, = 2 ( -~= + ~-- ) {J = 0.84{J )20.7 fti0 (iii) I1Enp = 2( -- 6- + -~){J = 1.47{J ,,/17.7 v17.7 (iv) I1En, = 2 ( -/ + 2 ) {J = 1.35{J ..;20.7 )20.7 Thus (iii) > (ii) > Ii): (iv) > (ii). -
Bimolecular Reaction Rate Coefficients in the Last Lecture, We Learned Qualitatively the Reaction Mechanisms of Hydrocarbon Combustion
Combustion Chemistry Hai Wang Stanford University 2015 Princeton-CEFRC Summer School On Combustion Course Length: 3 hrs June 22 – 26, 2015 Copyright ©2015 by Hai Wang This material is not to be sold, reproduced or distributed without prior written permission of the owner, Hai Wang. Lecture 4 4. Bimolecular Reaction Rate Coefficients In the last lecture, we learned qualitatively the reaction mechanisms of hydrocarbon combustion. To make this description quantitative, we will need to have a basic knowledge of reaction rate theories. While the rate coefficients of a large number of combustion reactions are experimentally measured, reaction rate theories are often necessary to interpret the experimental data. We shall focus our discussion here to bimolecular reactions of the type A + B → C + D and leave the discussion for unimolecular reactions to a later time. 4.1 Hard Sphere Collision We discussed earlier that an elementary chemical reaction requires molecular collision. The rate coefficient of a bimolecular reaction is essentially the product of reaction probability of two reactants (A and B) upon collision at a given temperature γ(T) and the frequency of collision ZAB, k(T) [A][B] = γ(T) ZAB (4.1) Here we assume that molecules may be described by rigid spheres. Figure 4.1 shows several scenarios of molecular encounter. Starting from the head-on collision, an offset of the two axes of molecular motion leads to off-center collision. Suppose the diameter of A and B are σA and σB, respectively. The limiting off-center collision would have a spacing equal to (σA+σB)/2 between the two axes of molecular motions. -
Effects of Impurities on an Industrial Crystallization Process of Ammonium Sulfate
Effects of impurities on an industrial crystallization process of ammonium sulfate Dissertation zur Erlangung des akademischen Grades Doktoringenieur (Dr.-Ing.) vorgelegt dem Zentrum für Ingenieurwissenschaften der Martin-Luther-Universität Halle-Wittenberg als organisatorische Grundeinheit für Forschung und Lehre im Range einer Fakultät (§ 75 Abs. 1 HSG LSA, § 1 Abs. 1 Grundordnung) von Herrn Dipl.-Ing. Robert Buchfink geboren am 18.04.1983 Gutachter: 1. Prof. Dr.-Ing. Dr. h.c. Joachim Ulrich 2. Prof. Dr. rer. nat. habil. Axel König Datum der Verteidigung: 02.05.2011 Halle (Saale), den 01.06.2011 Acknowledgment First of all I want to thank my family including my parents Gunter und Sigrid, my sister Lydia and my grandfather Walter. I wished my grandmother Hanni could have seen me getting a PhD degree. All of them gave me a great support, both financial and moral, over the long period of study and up to now we have a fantastic relationship. Furthermore, I want to acknowledge the support of my girlfriend Elli who was always there for me in good and in bad times. No PhD thesis without a supervisor, an institute and a topic. In this context I want to thank Prof. Dr.-Ing. Dr. h.c. Joachim Ulrich who gave me the great opportunity to work at his institute and who supervised my research in the interesting field of crystallization. Moreover, I also want to thank Prof. Ulrich for creating the institute as a melting pot of international students which opened my mind in many ways and gave me the opportunity to get close friendships and learn much about the culture of different nations. -
Investigation of Charge Transport/Transfer and Charge Storage at Mesoporous Tio2 Electrodes in Aqueous Electrolytes Yee Seul Kim
Investigation of charge transport/transfer and charge storage at mesoporous TiO2 electrodes in aqueous electrolytes Yee Seul Kim To cite this version: Yee Seul Kim. Investigation of charge transport/transfer and charge storage at mesoporous TiO2 electrodes in aqueous electrolytes. Other. Université Sorbonne Paris Cité, 2018. English. NNT : 2018USPCC161. tel-02407183 HAL Id: tel-02407183 https://tel.archives-ouvertes.fr/tel-02407183 Submitted on 12 Dec 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. UNIVERSITE PARIS DIDEROT (PARIS 7) Sorbonne Paris Cité Ecole doctorale de Chimie Physique et Chimie Analytique de Paris-Centre (ED 388) Laboratoire d’Electrochimie Moléculaire DOCTORAT ELECTROCHIMIE Yee-Seul KIM Investigation of charge transport/transfer and charge storage at mesoporous TiO2 electrodes in aqueous electrolytes Thèse dirigée par Véronique Balland et co-encadrée par Benoît Limoges Soutenue le 08 Novembre 2018 Rapporteurs : Marie-Noëlle COLLOMB DR, Université Grenoble Alpes Jean-Pierre PEREIRA-RAMOS DR, Université Paris-Est Président du jury : Christel LABERTY-ROBERT PR, Sorbonne Université Examinateur : Hyacinthe RANDRIAMAHAZAKA PR, Université Paris Diderot Directrice de thèse : Véronique BALLAND MCU HDR, Université Paris Diderot Co-directeur de thèse : Benoît LIMOGES DR, Université Paris Diderot Acknowledgement Foremost, I would first like to thank my reviewers, Dr. -
Environmental Speciation and Monitoring Needs for Trace Metal -Contai Ni Ng Substances from Energy-Related Processes
STAND NATL iNST OF AU107 1=17^05 NBS 1>l PUBLICATIONS z CO NBS SPECIAL PUBLICATION * / Of U.S. DEPARTMENT OF COMMERCE / National Bureau of Standards -QC 100 .U57 NO. 618 1981 c. 2 NATIONAL BUREAU QF STANDARDS The National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system of physical and chemical and materials measurement; coordinates the system with measurement systems of other nations and furnishes essential services leading to accurate and uniform physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement, standards, and data on the properties of materials needed by industry, commerce, educational institutions, and Government; provides advisory and research services to other Government agencies; develops, produces, and distributes -
Nbs Special Publication 618 4
f ) F T~AO F C NBS SPECIAL PUBLICATION 618 4- NATIONAL BUREAU OF STANDARDS The National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and the Institute for Computer Sciences and Technology. THE NATIONAL MEASUREMENT LABORATORY provides the national system of physical and chemical and materials measurement, coordinates the system with measurement systems of other nations anci f-irnishes essential services leading to accurate and uniform physical and chemical measurement throughout the Nation's scientific community, industry, and commerce; conducts materials research leading to improved methods of measurement, standards, and data on the properties of materials needed by industry, commerce, educational institutions, and Government, provides advisory and research services to other Government agencies: develops, produces, and distributes Standard Reference Materials; and provides calibration services. The Laboratory consists of the following centers: 2 Absolute Physical -
Formation of Complexes from Aquo Ions the Complex Formation from the Aquo Ions Yields the Assembly Containing Metal Ions with Only Water As Ligands
82 A Textbook of Inorganic Chemistry – Volume I Formation of Complexes from Aquo Ions The complex formation from the aquo ions yields the assembly containing metal ions with only water as ligands. These complexes are the major components in aqueous solutions of many metal salts, like metal z+ sulphates, perchlorates and nitrates. The formula for metal-aquo complexes [M(H2O)n] where the value of z generally varies from +2 to +4. The metal-aquo complexes play some very important roles in biological, industrial and environmental aspects of chemistry. Now though the homoleptic aquo complexes (only with H2O as the ligands attached) are very common, there are many other complexes that are known to have a mix of aquo and other ligand types. Figure 13. Structure of an octahedral metal aquo complex. The most common stereochemistry for metal-aquo complexes is octahedral with the formula 2+ 3+ [M(H2O)6] and [M(H2O)6] ; nevertheless, some square-planar and tetrahedral complexes with the formula 2+ [M(H2O)4] are also known. A general discussion on the different types and other properties is given below. Six-Coordinated Metal-Aquo Complexes Most of the transition metal elements from the first transition series and some alkaline earth metals form hexa-coordinated complexes when their corresponding salts are dissolved in water. Some of the most studied hexa-coordinated complexes are given below. Figure 14. Structure of six-coordinated metal-aquo complexes. Copyright © Mandeep Dalal CHAPTER 3 Reaction Mechanism of Transition Metal Complexes – I: 83 Four-Coordinated Metal-Aquo Complexes The metal-aquo complexes that exist with coordination numbers lower than six are very uncommon 2+ 2+ 2+ but not absent from the domain.