The Specification of Bonding Cavities in Macrocyclic Ligands

Henrick, Kim; Tasker, Peter A.; Lindoy, Leonard F.

doi:10.1002/9780470166345.ch1

Cited by 59 publications

(4 citation statements)

References 94 publications

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“…Coordination of metal ions, which are small compared to the cavity size of the planar porphyrin, induces out-of-plane (oop) distortions [17,19,20], for example, nickel (II) ions. The optimal metal-nitrogen distance for a planar metalloporphyrin is about 2.01 Å [21,22], while Ni-N bonds prefer a shorter bond length of 1.85 Å [23]. As a result, the Ni-N bonds pull the pyrrole rings toward the center which induces oop deformations of the macrocycle.…”

Section: Introductionmentioning

confidence: 99%

Sterically induced distortions of nickel(II) porphyrins – Comprehensive investigation by DFT calculations and resonance Raman spectroscopy

Schindler

Kupfer

Ryan

et al. 2018

Coordination Chemistry Reviews

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nickel(II) porphyrins in dichloromethane is reported to comprehensively access their sterically induced distortions from planarity. Thus, the tutorial review focuses on both resonance Raman spectroscopic investigations and structural investigations based on DFT. We relate different theoretical and experimental methodologies to predict out-of-plane distortions of the porphyrin macrocycles which are quantified by normal-coordinate structural decomposition. This comprehensive compilation reveals shortcomings in the molecular mechanic calculations and illustrates the impact of crystal packing forces on crystal structures. Non-planar distortions shift the experimentally observed resonance Raman marker bands v 2 , v 3 and v 4 to lower frequency. A revised correlation between this shift and the calculated structural parameter (ruffling angle) is presented and reveals deviations from reported correlations based on molecular mechanics.

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Section: Introductionmentioning

confidence: 99%

Sterically induced distortions of nickel(II) porphyrins – Comprehensive investigation by DFT calculations and resonance Raman spectroscopy

Schindler

Kupfer

Ryan

et al. 2018

Coordination Chemistry Reviews

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“…The approach of using the cavity size in macrocyclic ligands to tune the strength of binding of base metal ions, established by Lindoy and co-workers, [63] can be extended to much simpler reagents such as the salicylaldehyde hydrazone ligands described in this work which assemble in pseudomacrocyclic structures via interligand hydrogen bonding.…”

Section: Discussionmentioning

confidence: 99%

Salicylaldehyde Hydrazones: Buttressing of Outer-Sphere Hydrogen-Bonding and Copper Extraction Properties

et al. 2017

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Salicylaldehydes hydrazones are weaker copper extractants than their oxime derivatives which are used in hydrometallurgical processes to recover approximately 20% of the world's copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. DFT calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pHdependent equilibrium:and on their ability to "buttress" interligand hydrogen bonding by interacting with the hydrazone N-H donor group. X-ray crystal structure determination and computed structures indicated that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen bond formation to the neighbouring phenolate oxygen atoms.

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“…In this case, however, a polymeric product is isolated together with [H2L56]( PF&. In addition, the "fit parameter" [31] decreases considerably. According to X-ray data [29], when passing from [Sn(CH3)2( L55)I2+ to [Sn(CH3)2( L56)I2+, there is a considerable change in the ligand cavity size, from 38 2 Template synthesis of polyazamacrocyclic compounds 23.2 to 21.0 nm.…”

Section: Cyclic Hydrazines and Hydrazonesmentioning

confidence: 96%

“…2.2). Attempts to prepare octaazamacrocyclic systems similar to L36 but derived from 31 other a-diketones failed [2]. The structure of both A and B isomers of [Ni(L38)] has been confirmed by X-ray diffraction studies [3, 41. Isomer A is the more stable.…”

Section: Cyclic Hydrazines and Hydrazonesmentioning

confidence: 99%

Template synthesis of polyazamacrocyclic compounds

Gérbéléu

Arion

Burgess

1999

Template Synthesis of Macrocyclic Compounds

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Compounds containing nitrogen in their cyclic backbone are one of the most representative groups of macrocyclic systems, and are very often synthesised by template reactions. The ligsons participating in the construction of ligand products must have certain groups or positions in moleculeswhich are sometimes concealed, revealing themselves when coordinated and activated by the template.Building up polyazamacrocyclic systems on the appropriate matrices is carried out by the interaction of compounds containing amine or imine groups with aldehydes, ketones, organic halogen derivatives, substituted malonic esters and ligsons containing unsaturated C-C bonds. The process may also be performed by interaction of the appropriate blocks, containing both functional groups necessary for obtaining the final product. Among such template reactions the most frequent is the formation of azomethine construction bonds, then C-N and C-C and in some cases, N=N chelatogene bonds.

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The Specification of Bonding Cavities in Macrocyclic Ligands

Cited by 59 publications

References 94 publications

Sterically induced distortions of nickel(II) porphyrins – Comprehensive investigation by DFT calculations and resonance Raman spectroscopy

Sterically induced distortions of nickel(II) porphyrins – Comprehensive investigation by DFT calculations and resonance Raman spectroscopy

Salicylaldehyde Hydrazones: Buttressing of Outer-Sphere Hydrogen-Bonding and Copper Extraction Properties

Template synthesis of polyazamacrocyclic compounds

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