Norbornadiene

About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.

Effective Hamiltonian Approach to Catalytic Activity of Transition Metal Complexes

Abstract: The application of an effective electron Hamiltonian approach to the description of the electronic structure of transition metal complexes with chemically active ligands is analyzed. This approach is implemented in a computational code. The evolution of the electronic structure along a path of isomerization of quadricyclane to norbornadiene in the coordination sphere of Co-tetraphenylporphyrin is considered. In addition, the electronic states of atomic oxygen coordinated to transition metal oxides and metal porphyrins are studied. c

Synthesis and Structure of Systems Containing Pyramidalized and Strained Double Bond: An Investigation on the Cycloaddition Reactions of cis- and trans-3,8-dicarbomethoxy-3,8-dihydroheptalene

Abstract: Strain can be introduced in a molecule by distorting one or more chemical bonds from their ”normal” bond lengths or bond angles. Alkenes in which the double bonds are distorted or pyramidalized are of theoretical interest and usually present a considerable challenge with regard to synthesis . Pyramidalized alkenes are molecules containing carbon-carbon bonds in which one or both of the sp carbon atoms do not lie in the plane of the attached atoms. Theoretical work has shown that a trigonal center of a double bond pyramidalizes when located in an asymmetrical environment. Evidence for pyramidalization was first obtained in NMR studies on norbornadiene and has been substantiated by X-ray studies of crystalline norbornenes and sesquinorbornenes .

Cyclodimerization of norbornadiene (NBD) into high energy-density fuel pentacyclotetradecane (PCTD) over mesoporous silica supported Co–Ni nanocatalyst

Abstract: The present study focuses on the synthesis of high energy-density fuel pentacyclotetradecane (PCTD) through cyclodimerization followed by hydrogenolysis of norbornadiene (NBD) over mesoporous silica-supported Co–Ni-based nanocatalyst. Catalytic materials are synthesized by incipient wetness impregnation method using Al-MCM-41, MCM-48 and γ-alumina as supporting materials for Co–Ni metals. The textural properties of the catalyst have been investigated through XRD, TEM and N2 physisorption, and the parameters concerning the reactivity of the catalyst optimized. The reaction was performed in a single pot (pressure reactor), and the structure of the product was elucidated by using FTIR and NMR techniques. The optimum reaction parameters (catalyst, temperature, and pressure) were developed to produce a yield of ≥ 85%. The physicochemical properties such as calorific value (10754 cal./g), density (1.08 g/cc), etc. were evaluated, and these can be utilized for ramjet application. Dimerization of NBD into a high energy-density pentacyclotetradecane fuel over mesoporous aluminosilicate supported Co–Ni nanocatalyst.

Energetics of photoconversion of norbornadiene to quadricyclane : Effects of directly attached substituents via ab initio and DFT

Abstract: An attempt is made to maximize the photochemical and/or solar energy storage in norbornadiene ( 1 )/quadricyclane ( 2 ) system, through direct attachment of substituents at C 1 , C 2 or C 7 atoms of 1 and 2 . Assessments of the corresponding energies are made at B3LYP/6-311++G* level of theory. Electron donating substituents, D (D=–NMe 2 , –NH 2 , –OMe, –OH, and Me), directly attached at C 2 , increase the energy gap between 1 and 2 , inducing higher storage of energy in the system. Electron withdrawing subsituents, W (W=–NO 2 , –F, –Cl, –Br, –CF 3 and –COOH), directly attached at C 1 , moderately induce the energy storage. Attachment of either D or W groups at C 7 show no significant difference in the photochemical and/or solar energy storages. A Hammet ρ value of −3.69 is encountered for substituents directly attached at C 2 atoms of 1 and 2 . This is in clear contrast to the Hammet ρ value of −0.81 that we recently reported for the subsituents indirectly placed at the C 2 of 1 and/or 2 (through attachment via the para carbon of phenyl rings).