A co-crystal of nonahydrated disodium(II) with mixed anions fromm-chlorobenzoic acid and furosemide

In the title compound, [Na2(H2O)9](C7H4ClO2)(C12H10ClN2O5S) {systematic name:catena-poly[[[triaquasodium(I)]-di-μ-aqua-[triaquasodium(I)]-μ-aqua] 3-chlorobenzoate 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoate]}, both the originalm-chlorobenzoic acid and furosemide exist with deprotonated carboxylates, and the sodium cations and water molecules exist in chains with stoichiometry [Na2(OH2)9]2+that propagate in the [-110] direction. Each of the two independent Na+ions is coordinated by three monodentate water molecules, two double-water bridges, and one single-water bridge. There is considerable cross-linking between the [Na2(OH2)9]2+chains and to furosemide sulfonamide and carboxylate by intermolecular O—H...O hydrogen bonds. All hydrogen-bond donors participate in a complex two-dimensional array parallel to theabplane. The furosemide NH group donates an intramolecular hydrogen bond to the carboxylate group, and the furosemide NH2group donates an intramolecular hydrogen bond to the Cl atom and an intermolecular one to them-chlorobenzoate O atom. The plethora of hydrogen-bond donors on the cation/water chain leads to many large rings, up to graph setR44(24), involving two chains and two furosemide anions. The chlorobenzoate is involved in only oneR22(8) ring, with two water moleculescis-coordinated to Na. The furan O atom is not hydrogen bonded.

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Elucidating the origins of enhanced CO2 reduction in manganese electrocatalysts bearing pendant hydrogen-bond donors

Dalton Transactions ◽

10.1039/c9dt02060h ◽

2019 ◽

Vol 48 (33) ◽

pp. 12730-12737 ◽

Cited By ~ 4

Author(s):

Steven E. Tignor ◽

Travis W. Shaw ◽

Andrew B. Bocarsly

Keyword(s):

Hydrogen Bond ◽

Intramolecular Hydrogen Bond ◽

Co2 Reduction ◽

Critical Importance ◽

Mechanistic Analysis ◽

Intramolecular Hydrogen ◽

Hydrogen Bond Donors

A mechanistic analysis showing the critical importance of an intramolecular hydrogen bond for improved insight and understanding in CO2 electroreduction.

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Stereoselective Ammonium-Directed Epoxidation in the Asymmetric Syntheses of Dihydroconduramines (–)-A-2, (–)-B-2, (–)-C-3 and (+)-F-3

Synthesis ◽

10.1055/s-0036-1590948 ◽

2017 ◽

Vol 50 (01) ◽

pp. 64-83 ◽

Cited By ~ 6

Author(s):

Stephen Davies ◽

Solange Da Silva Pinto ◽

Ai Fletcher ◽

Paul Roberts ◽

James Thomson

Keyword(s):

Hydrogen Bond ◽

Intramolecular Hydrogen Bond ◽

Ring Opening ◽

Asymmetric Syntheses ◽

Directing Group ◽

Intramolecular Hydrogen ◽

Hydrogen Bond Donors

Epoxidation of racemic trans-2-(N,N-dibenzylamino)cyclohex-3-en-1-ol, upon treatment with Cl3CCO2H then m-CPBA, proceeded with poor diastereoselectivity (ca. 60:40 dr), whilst epoxidation of racemic trans-2-(N-benzylamino)cyclohex-3-en-1-ol under the same conditions proceeded with high diastereoselectivity (>95:5 dr) and was followed by completely regioselective and stereospecific ring-opening in situ to give, after methanolysis of the intermediate trichloroacetate ester, (1RS,2SR,3SR,4SR)-2-(N-benzylamino)cyclohexane-1,3,4-triol. Use of aq HBF4 as the acid protecting agent gave the amino triol directly. The differing diastereoselectivities of these epoxidation reactions may be due to a predilection towards formation of an intramolecular hydrogen-bond in the former substrate disrupting the ability of the in situ formed ammonium moiety to act as a directing group for the incoming oxidant; the presence of two potential hydrogen-bond donors (i.e., two N–H bonds) in the latter substrate circumvents this limitation. With the criterion for a highly diastereoselective (ammonium-directed) epoxidation in this system established, a synthesis of enantiopure trans-2-(N-benzylamino)cyclohex-3-en-1-ol (>99% ee) was developed and the ammonium-directed epoxidation was then employed as a key synthetic step to facilitate the asymmetric syntheses of enantiopure dihydroconduramines (–)-A-2, (–)-B-2, (–)-C-3 and (+)-F-3 (>98% ee in each case) from 1,3-cyclohexadiene.

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Poly[μ-aqua-aqua-μ-3-carboxypyrazine-2-carboxylato-sodium(I)]

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536806008130 ◽

2006 ◽

Vol 62 (5) ◽

pp. m945-m947 ◽

Cited By ~ 7

Author(s):

Mustafa Tombul ◽

Kutalmış Güven ◽

Nazım Alkış

Keyword(s):

Crystal Structure ◽

Hydrogen Bond ◽

Coordination Number ◽

Intramolecular Hydrogen Bond ◽

Title Compound ◽

Carboxyl Groups ◽

Water Molecules ◽

Dimeric Unit ◽

Carboxylate Groups ◽

Intramolecular Hydrogen

The crystal structure of the title compound, [Na(C6H3N2O4)(H2O)2] n , consists of molecular ribbons containing octahedral NaO5N units. Two adjacent Na atoms are bridged by two water molecules to give a centrosymmetric dimeric unit. Each Na centre is coordinated by two carboxylate groups. The ligand also uses one N atom to coordinate to Na. In addition, each Na atom is coordinated by one water O atom, raising the coordination number to six. One of the carboxyl groups retains its H atom, which takes part in an O—H...O [O...O = 2.563 (1) Å] intramolecular hydrogen bond.

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Competition between the intramolecular hydrogen bond and the π-electron delocalization in some RAHB systems: A theoretical study

Журнал структурной химии ◽

10.26902/jsc_id40420 ◽

2019 ◽

Vol 60 (5) ◽

Keyword(s):

Hydrogen Bond ◽

Intramolecular Hydrogen Bond ◽

Theoretical Study ◽

Electron Delocalization ◽

Intramolecular Hydrogen

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Effect of the intramolecular hydrogen bond in the active metabolite analogs of leflunomide for blocking the Plasmodium falciparum dihydroorotate dehydrogenase enzyme: QTAIM, NBO, and docking study

Current Computer - Aided Drug Design ◽

10.2174/1573409916666200527133126 ◽

2020 ◽

Vol 16 ◽

Author(s):

Reihaneh Heidarian ◽

Mansoureh Zahedi-Tabrizi

Keyword(s):

Hydrogen Bond ◽

Plasmodium Falciparum ◽

Molecular Orbital ◽

Intramolecular Hydrogen Bond ◽

Active Metabolite ◽

Chemical Hardness ◽

Dihydroorotate Dehydrogenase ◽

Molecular Orbital Analysis ◽

Intramolecular Hydrogen ◽

Orbital Analysis

: Leflunomide (LFM) and its active metabolite, teriflunomide (TFM), have drawn a lot of attention for their anticancer activities, treatment of rheumatoid arthritis and malaria due to their capability to inhibit dihydroorotate dehydrogenase (DHODH) and Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. In this investigation, the strength of intramolecular hydrogen bond (IHB) in five analogs of TFM (ATFM) has been analyzed employing density functional theory (DFT) using B3LYP/6-311++G (d, p) level and molecular orbital analysis in the gas phase and water solution. A detailed electronic structure study has been performed using the quantum theory of atoms in molecules (QTAIM) and the hydrogen bond energies (EHB) of stable conformer obtained in the range of 76-97 kJ/mol, as a medium hydrogen bond. The effect of substitution on the IHB nature has been studied by natural bond orbital analysis (NBO). 1H NMR calculations show an upward trend in the proton chemical shift of the enolic proton in the chelated ring (14.5 to 15.7ppm) by increasing the IHB strength. All the calculations confirmed the strongest IHB in 5-F-ATFM and the weakest IHB in 2-F-ATFM. Molecular orbital analysis, including the HOMO-LUMO gap and chemical hardness, was performed to compare the reactivity of inhibitors. Finally, molecular docking analysis was carried out to identify the potency of inhibition of these compounds against PfDHODH enzyme.

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