Coordination Chemistry of 2,2’-Dipyridylamine: The Gift That Keeps on Giving

Brogden, David W.; Berry, John F.

doi:10.1080/02603594.2015.1079522

Cited by 42 publications

(53 citation statements)

References 78 publications

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“…Over the past decade, we and others have studied heterometallic extended metal atom chains (HEMACs), which contain a linear string of three or more metal centers supported by four triply bridging ligands. Of specific interest to this work are trimetallic HEMACs of the form M A ≣M A −M B in which a quadruply bonded pair of group VI metals is appended to a high‐spin divalent first row transition metal.…”

Section: Methodsmentioning

confidence: 99%

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Chipman

Berry

2017

Chemistry A European J

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The new heterometallic chain compounds Mo Ni(dpa) Cl (1) and [Mo Ni(dpa) Cl ]OTf (2) (dpa=2,2'-dipyridylamine) have been prepared and studied by crystallography and magnetic susceptibility, among other methods. Oxidation of 1 to 2 removes an electron from the multiply bonded Mo unit, consistent with the formulation of 2 containing a (Mo ) ⋅⋅⋅(Ni) core. While 1 contains an S=1, pseudo-octahedral Ni ion, 2 has an S=3/2 ground state, in which the two Ni unpaired electrons, one in a localized δ-orbital and one in a heavily delocalized σ -orbital are joined by an unpaired electron in a Mo-Mo δ-orbital. The S=3/2 ground state is persistent to 300 K, evidencing strong ferromagnetic coupling of the Mo and Ni spins with J≥150 cm . This ferromagnetic interaction occurs via delocalization of a σ -electron across all three metal atoms, forcing ferromagnetic alignment of electrons in orthogonal Ni and Mo δ-symmetry orbitals. We anticipate that this new means of coupling spins can be used as a design principle for the preparation of new compounds with high spin ground states.

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Section: Methodsmentioning

confidence: 99%

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Chipman

Berry

2017

Chemistry A European J

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“…11,12 This ligand geometry is efficient in promoting formation of metal-metal bonds, but the exact pattern of metal-metal distances and the extent of bond delocalization have represented a much debated issue. Especially controversial is the interpretation of crystallographic data for tri-and pentachromium(II) derivatives [Cr 3 (dpa) 4 Cl 2 ] (1) and [Cr 5 (tpda) 4 Cl 2 ] (2) (see Scheme 1), which both behave as single molecule magnets at low temperature (Hdpa = N-( pyridin-2-yl)pyridin-2-amine, 13 H 2 tpda = N 2 ,N 6 -bis( pyridin-2-yl)pyridine-2,6-diamine, see Scheme 1). 14,15 The solid-state structures of these EMACs show metal atoms with abnormally elongated ( prolate) displacement ellipsoids along the chain axis, which can be interpreted as due to either large thermal vibrations or to positional disorder effects.…”

Section: Introductionmentioning

confidence: 99%

Solution structure of a pentachromium(ii) single molecule magnet from DFT calculations, isotopic labelling and multinuclear NMR spectroscopy

et al. 2018

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The structure of pentachromium(ii) extended metal atom chain [Cr(tpda)Cl] (2), which behaves as a single molecule magnet at low temperature, was investigated by Density Functional Theory (DFT) calculations and spectroscopic studies without the constraints of a crystal lattice (Htpda = N,N-bis(pyridin-2-yl)pyridine-2,6-diamine). DFT studies both in the gas phase and including CHCl solvent effects indicate that an unsymmetric structure (C point group), with pairs of formally quadruply-bonded metal ions and one terminal metal center, is slightly more stable (2.9 and 3.9 kcal mol) than a symmetric structure (D point group). Isotopically-labelled samples (2-d and 2-d) have then been prepared to aid in molecular symmetry determination by combined H andH NMR studies in dichloromethane solution. The spectra are strongly suggestive of a symmetric (D) framework, indicating fast shuttling between the two unsymmetric forms over the timescale of NMR experiments. Procedures for a high-yield Pd-free synthesis of Htpda and for site-selective post-synthetic H/D exchange of aromatic Htpda hydrogens are also reported.

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“…Although less prevalent throughout organometallic chemistry than HMDS, 49 amido DPA has been utilised in a number of varied branches of chemistry 50 including materials science, 51 catalysis, 52 supramolecular chemistry 53 and even in cooperative bimetallic chemistry. 54 Being the simplest of the DPA through three N sites; one central amido N and two neutral pyridyl N atoms.…”

Section: Introductionmentioning

confidence: 99%

Synthetic, structural and magnetic implications of introducing 2,2′-dipyridylamide to sodium-ferrate complexes

et al. 2017

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This version is available at https://strathprints.strath.ac.uk/60604/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Using a transamination approach to access novel Fe(II) complexes, this study presents the synthesis, X-ray crystallographic and magnetic characterisation of a series of new iron complexes containing the multifunctional 2,2-dipyridylamide (DPA) ligand using iron bis(amide) [{Fe(HMDS)2}2] and sodium ferrate [{NaFe(HMDS)3} ] (1) as precursors (HMDS = 1,1,1,3,3,3hexamethyldisilazide). Reactions of DPA(H) with 1 show exceptionally good stoichiometric control, allowing access to heteroleptic [(THF)2·NaFe(DPA)(HMDS)2] (3) and homoleptic [{THF·NaFe(DPA)3} ] (4) by using 1 and 3 equivalents of DPA(H) respectively. Linking this methodology and co-complexation, which is a more widely used approach to prepare heterobimetallic complexes, 3 can also be prepared by combining NaHMDS with heteroleptic [{Fe(DPA)(HMDS)}2] (2). In turn, 2 has been also synthesised and structurally defined by reacting [{Fe(HMDS)2}2] with two equivalents of DPA(H). Structural studies demonstrate the coordination flexibility of the N-bridged bis(heterocycle) ligand DPA, with 2 and 3 exhibiting discrete monomeric motifs, whereas 4 displays a much more intricate supramolecular structure, with one of its DPA ligands coordinating in an anti/anti fashion (as opposed to 2 and 3 where DPA shows a syn/syn conformation), which facilitates propagation of the structure via its central amido N. Magnetic studies confirmed the high-spin electron configuration of the iron(II) centres in all three compounds and revealed the existence of weak ferromagnetic interactions in dinuclear compound 2 (J = 1.01 cm -1 ). Journal Name ARTICLE

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Coordination Chemistry of 2,2’-Dipyridylamine: The Gift That Keeps on Giving

Cited by 42 publications

References 78 publications

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Solution structure of a pentachromium(ii) single molecule magnet from DFT calculations, isotopic labelling and multinuclear NMR spectroscopy

Synthetic, structural and magnetic implications of introducing 2,2′-dipyridylamide to sodium-ferrate complexes

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Coordination Chemistry of 2,2’-Dipyridylamine: The Gift That Keeps on Giving

Cited by 42 publications

References 78 publications

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm−1) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm−1) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Solution structure of a pentachromium(ii) single molecule magnet from DFT calculations, isotopic labelling and multinuclear NMR spectroscopy

Synthetic, structural and magnetic implications of introducing 2,2′-dipyridylamide to sodium-ferrate complexes

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Product

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Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex

Extraordinarily Large Ferromagnetic Coupling (J≥150 cm⁻¹) by Electron Delocalization in a Heterometallic Mo≣Mo−Ni Chain Complex