Metal Organo-Polymeric Framework via [2 + 2] Cycloaddition Reaction: Influence of Hydrogen Bonding on Depolymerization

The origin of stereoselectivity for [4+2] cycloaddition reaction of methyl methacrylate with cyclopentadiene was investigated with the B3LYP-D3(BJ)/6-31+G(d)//B3LYP/6-31+G(d) level of theory in the presence of the ionic liquid 1-ethyl-3-methyl-imidazolium chloride (EMI+Cl–) and its acidic chloroaluminate melt, 1-ethyl-3-methyl-imidazolium heptachlorodialuminate (EMI+Al2Cl7–). The reaction of methyl methacrylate with cyclopentadiene was examined in the gas phase to rationalize the effect of the ionic liquid ion pairs EMI+Cl– and EMI+Al2Cl7–. The DFT calculated results were found to be in good agreement with the experimentally observed results. The much-discussed hydrogen bonding effect of the imidazolium cation with the dienophile is less important to govern the stereoselectivity for the cycloaddition reaction. The atoms in molecules theory was used to examine the role of hydrogen bonding between the EMI+ cation and methyl methacrylate in the transition state geometries. The calculated activation barriers with the M062X/6-31+G(d)//B3LYP/6-31+G(d) and MP2/6-311+G(d,p)//B3LYP/6-31+G(d) levels of theory also predict the similar exo/endo-stereoselectivity trend for the cycloaddition reactions.

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Two new bis(pyridine)-bis(amide)-based copper(II) coordination compounds for the electrochemical detection of trace Cr(VI) and efficient electrocatalytic oxygen evolution

Zeitschrift für Naturforschung B ◽

10.1515/znb-2021-0180 ◽

2022 ◽

Vol 0 (0) ◽

Author(s):

Hong-Yan Lin ◽

Qian-Qian Liu ◽

Yuan Tian ◽

Ling Zeng

Keyword(s):

Hydrogen Bonding ◽

Oxygen Evolution ◽

Electrochemical Detection ◽

Layered Structure ◽

Coordination Compounds ◽

Carbon Paste ◽

Nitrobenzoic Acid ◽

Polymeric Chains ◽

Metal Organic ◽

Polymeric Framework

Abstract Two new metal-organic compounds (MOCs) [Cu(L)0.5(3-nba)2] (1) and [Cu(L)(2,5-tdc)] (2) have been hydrothermally synthesized by employing the ligand N,N′-di(3-pyridyl)adipoamide (L) and two carboxylic acids (3-Hnba = 3-nitrobenzoic acid, 2,5-H2tdc = 2,5-thiophenedicarboxylic acid) as ligands. Compound 1 displays a metal-organic chain-like structure formed by the {Cu2(3-nba)4} double-paddle wheel units and the µ 2-bridging L ligands. The adjacent polymeric chains form a supramolecular layered structure through hydrogen bonding. Compound 2 shows a 3D metal-organic polymeric framework derived from Cu-L layers and µ 2-bridging 2,5-tdc ligands, which presents a 3,5-connected {4.62}{4.66.83} topology. The electrochemical and electrocatalytic behavior of the two compounds has been studied in detail. Carbon paste working electrodes modified with compounds 1 and 2 can be used as highly selective sensors for detecting traces Cr(VI). Both electrodes show also electrocatalytic performance in oxygen evolution reactions (OERs).

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A calcium-bridged porphyrin coordination network

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424602000464 ◽

2002 ◽

Vol 06 (06) ◽

pp. 377-381 ◽

Cited By ~ 25

Author(s):

Margaret E. Kosal ◽

Jun-Hong Chou ◽

Kenneth S. Suslick

Keyword(s):

Hydrogen Bonding ◽

Solid State ◽

Coordination Polymers ◽

Three Dimensional ◽

Pyridine Molecule ◽

Two Dimensional ◽

X Ray ◽

Hydrogen Bonding Interactions ◽

Dimensional Network ◽

Polymeric Framework

The hydrothermal assembly of a very stable porphyrin network with nanoscale cavities is described. A tightly packed and interpenetrated, linear polymeric framework was observed in the solid-state X-ray structure of freebase 5,10,15,20-tetrakis-(4-carboxyphenyl)porphyrin coordinated to calcium(II) ions. Strong hydrogen-bonding interactions between the coordination polymers form a two-dimensional network. Perpendicular bands interpenetrate generating an unusual three-dimensional box that clathrates a pyridine molecule.

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7-(Biphenyl-4-yl)-6-hydroxyindan-1-one

IUCrData ◽

10.1107/s2414314619009519 ◽

2019 ◽

Vol 4 (7) ◽

Author(s):

Ryan N. McCoy ◽

Katherine N. Robertson ◽

Kai E. O. Ylijoki

Keyword(s):

Hydrogen Bonding ◽

Title Compound ◽

Cycloaddition Reaction ◽

Carbonyl Groups ◽

Compound C ◽

Crude Reaction Mixture ◽

A Minor

The title compound, C21H16O2, was isolated from the reaction of 1-(2-methoxyethoxy)-1-vinylcyclopropane, 4-ethynylbiphenyl, and CO in a [5 + 1 + 2 + 1] cycloaddition reaction catalysed by [Rh(CO)2Cl]2. The crystals precipitated directly from the crude reaction mixture. A hydrogen-bonding framework between the hydroxy and carbonyl groups of a symmetry-related neighbour connects the molecules into chains running parallel to the crystallographic c axis. A minor non-merohedral twin component was included in the refinement.

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The mechanism of stereoselectivity in the cycloaddition reactions of α-hydroxy-ortho-quinodimethanes with the fumarate of methyl lactate and mandelate

Canadian Journal of Chemistry ◽

10.1139/v93-110 ◽

1993 ◽

Vol 71 (6) ◽

pp. 827-833 ◽

Cited By ~ 3

Author(s):

James L. Charlton ◽

Shawn Maddaford

Keyword(s):

Hydrogen Bonding ◽

Cycloaddition Reaction ◽

Diels Alder ◽

Asymmetric Induction ◽

Cycloaddition Reactions ◽

Methyl Lactate ◽

Very High

The Diels–Alder cycloaddition reaction of the fumarate of methyl lactate or methyl mandelate with α-hydroxy-ortho-quinodimethane produces an unexpected exo product with very high asymmetric induction. Experiments and calculations have been carried out that show that the origin of the stereoselectivity in these reactions is related to hydrogen bonding between the α-hydroxy-o-quinodimethane and the lactate or mandelate group in the dienophile.

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