Self-Assembly of a Three-Dimensional [Ga6(L2)6] Metal-Ligand “Cylinder”

Johnson, Darren W.; Xu, Jide; Saalfrank, Rolf W.; Raymond, Kenneth N.

doi:10.1002/(sici)1521-3773(19991004)38:19<2882::aid-anie2882>3.0.co;2-t

Cited by 89 publications

(21 citation statements)

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“…[8] An alternative strategy has been the design and preparation of complicated multidentate ligands favoring the assembly of metal ions into aggregates with topologies that may be anticipated from the structure of these ligands. This second course of action has led to the production of a large amount of polynuclear edifices displaying sophisticated shapes and architectures, such as helicates, [9] grids, [10] cylinders, [11] catenates, [12] and many more. Of these molecular species, only a minority have the metal ions disposed in close proximity so as to show cooperative effects resulting from strong magnetic-exchange interactions [13] or metalmetal bonding.…”

Section: (Py) 5 ] (1) Which Displays An Un-mentioning

confidence: 97%

A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand

et al. 2006

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Keywords: Ligand design / O ligands / NMR spectroscopy / Magnetism / MnA new ligand, H 5 L3, has been synthesized featuring seven linearly arranged oxygen donors in form of two 1,3-diketone and three phenol groups. The X-ray structure of H 5 L3 unveils a rare case where one of the diketones is in the enolic form and the other one in the bis(carbonyl) form. This structure is shown by 1 H NMR to persist in solution. Reaction of H 5 L3 with Mn(AcO) 2 in pyridine leads to the novel tetranuclear cluster [Mn 4 (H 2 L3) 2 (OAc) 2 (py) 5 ] (1), which displays an un-The preparation of molecular cluster complexes of interacting transition-metal ions is useful to areas as important and diverse as molecular magnetism, [1,2] homogeneous catalysis [3] or bioinorganic chemistry. [4,5] A very successful approach for accessing such species has been the assembly of metal ions by means of small bridging ligands, such as carboxylates, where growth into infinite arrays is often prevented by additional terminal ligands. [6,7] Such a method has been sometimes termed "serendipitous approach" since it does not allow prediction of the structure of the final species.[8] An alternative strategy has been the design and preparation of complicated multidentate ligands favoring the assembly of metal ions into aggregates with topologies that may be anticipated from the structure of these ligands. This second course of action has led to the production of a large amount of polynuclear edifices displaying sophisticated shapes and architectures, such as helicates, [9] grids, [10] cylinders, [11] catenates, [12] and many more. Of these molecular species, only a minority have the metal ions disposed in close proximity so as to show cooperative effects resulting from strong magnetic-exchange interactions [13] or metalmetal bonding.[ Scheme 1), [15,16] aimed at forming molecular strings of metal ions in close proximity. Maximum occupancy of their coordination pockets would result in tetranuclear clusters in form of [M 4 ] chains [17] for H 3 L1 and aligned [M 2 ] 2 dimers of dimers for H 4 L2. Reactions of the latter with M(OAc) 2 salts have resulted invariably in the formation of complexes of the type [M 2 (H 2 L2) 2 (S) n ] (n = 2 or 4; S = solvent; M = Mn, Ni, Co, Cu).[16] Similar dinuclear compounds have been obtained with H 3 L1.[18] However, in the absence of a coordinating solvent, molecules exhibiting higher occupancy, [Co 3 (HL1) 3 ] and [Mn 3 (HL1) 3 ], were characterized, which represented a new asymmetric topology within the context of coordination helicates. [19] Inspired by these early results, we have now designed and synthesized a new ligand displaying as many as six adjacent coordination pockets (H 5 L3, Scheme 1). Reaction of H 5 L3 with Mn II produces a very rare magnetically exchanged tetranuclear complex featuring an [Mn 4 O 6 ] core in form of a zig-zag chain.The new ligand H 5 L3 {2-hydroxy-1,3-bis[3-(2-hydroxyphenyl)-3-oxopropionyl]benzene} was prepared from the methoxide derivative H 4 L4 (Scheme 1).[20] The latter is also a n...

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Section: (Py) 5 ] (1) Which Displays An Un-mentioning

confidence: 97%

A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand

et al. 2006

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“…Raymond et al reported an M 6 L 6 trigonal antiprism complex from the combination of a C 3 -symmetric tris ¢-diketone ligand 5 3¹ and six-coordinate Ga III ( Figure 7). 27 In the [Ga 6 5 6 ] complex, three ¢-diketone binding sites of the ligand 5 3¹ are in different environments, and the whole framework has an idealized D 3 point group symmetry. Tris(¢-diketonato) Ga III units in one complex have the same optical isomerism, all-Δ or all-Λ (Figure 7b).…”

Section: ç Desymmetrization By Rigid Ligand Scaffoldsmentioning

confidence: 99%

Elaborate Metallosupramolecular Architectures through Desymmetrization Self-assembly of Symmetric Building Blocks

2013

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Desymmetrization self-assembly of symmetric building blocks is a powerful method to construct elaborate metallosupramolecular architectures. Herein several examples are given to discuss how to build up self-assembled complexes with low symmetry, focusing on 1) stabilization of local structural motifs by template molecules and/or interligand interactions, 2) rigidity regulation of ligand scaffolds, and 3) control of intermediate complexation conditions. Unsymmetrically assembled supramolecular host complexes exhibit unique functions reflecting their structural frameworks. Ç IntroductionThree-dimensional arrangement of molecular components is an efficient tool to construct platforms for elaborate chemical functions within isolated inner spaces. For example, natural enzymes perform highly selective molecular recognition and catalytic reactions utilizing cooperative effects of functional amino acid residues arranged around their active sites (Figure 1a), 1 where the positions of the functional groups and environments of active sites are well-defined by the folded protein scaffold. However, when considering the structural modification for further applications, it is still difficult to design and predict the folding behaviors of chemically modified macromolecules.2 Self-assembly of artificial molecular components is a powerful method for the construction of discrete and welldefined three-dimensional architectures.3 In this supramolecular approach, purposely designed building blocks are equipped with multiple functional groups to exert reversible intermolecular interactions between them. Coordination bonds, 4 hydrogen bonds, 5 electrostatic interactions, 6 and hydrophobic effects 7 are utilized to assemble individual building blocks into finite desired structures under appropriate conditions. In particular, coordination-driven self-assembly of organic ligands and metal ions has advantages in terms of the directionality and stability of coordination bonds, and design versatility of organic ligands.Organic ligands with multiple metal binding sites are required for assembling each component via coordination bonding. In general, when ligands that have chemically equivalent metal binding sites and therefore high symmetry are employed, the resulting supramolecular complexes also tend to possess uniform, highly symmetric frameworks. This is because; 1) direction and strength of coordination bonds between chemically equivalent binding sites and metal ions are usually equal; and 2) the self-assembly process is thermodynamically controlled where the products are formed as the result of repetitive bond formation and dissociation.In this context, construction of unsymmetrically selfassembled architectures is a challenging issue. Realization of such structures has a substantial impact, because it allows selfassembled unities to have elaborate functions by arranging molecular components in less symmetric but well-organized manners, which is reminiscent of natural enzymes.8 Common strategies to construct more intricate self-a...

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“…In these processes, the formation of the desired products from the building blocks occur spontaneously and efficiently in one pot. For the spontaneous self-assembly of supramolecular coordination complexes including 1D-, 2D-, and 3D-network structures and grids, appropriate precursor building blocks are reacted in the presence of metal ions as templates [13][14][15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Self-Assembly of Antiferromagnetically-Coupled Copper(II) Supramolecular Architectures with Diverse Structural Complexities

et al. 2020

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The self-assembly of 2,6-diformyl-4-methylphenol (DFMP) and 1-amino-2-propanol (AP)/2-amino-1,3-propanediol (APD) in the presence of copper(II) ions results in the formation of six new supramolecular architectures containing two versatile double Schiff base ligands (H3L and H5L1) with one-, two-, or three-dimensional structures involving diverse nuclearities: tetranuclear [Cu4(HL2−)2(N3)4]·4CH3OH·56H2O (1) and [Cu4(L3−)2(OH)2(H2O)2] (2), dinuclear [Cu2(H3L12−)(N3)(H2O)(NO3)] (3), polynuclear {[Cu2(H3L12−)(H2O)(BF4)(N3)]·H2O}n (4), heptanuclear [Cu7(H3L12−)2(O)2(C6H5CO2)6]·6CH3OH·44H2O (5), and decanuclear [Cu10(H3L12−)4(O)2(OH)2(C6H5CO2)4] (C6H5CO2)2·20H2O (6). X-ray studies have revealed that the basic building block in 1, 3, and 4 is comprised of two copper centers bridged through one μ-phenolate oxygen atom from HL2− or H3L12−, and one μ-1,1-azido (N3−) ion and in 2, 5, and 6 by μ-phenoxide oxygen of L3− or H3L12− and μ-O2− or μ3-O2− ions. H-bonding involving coordinated/uncoordinated hydroxy groups of the ligands generates fascinating supramolecular architectures with 1D-single chains (1 and 6), 2D-sheets (3), and 3D-structures (4). In 5, benzoate ions display four different coordination modes, which, in our opinion, is unprecedented and constitutes a new discovery. In 1, 3, and 5, Cu(II) ions in [Cu2] units are antiferromagnetically coupled, with J ranging from −177 to −278 cm−1.

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Self-Assembly of a Three-Dimensional [Ga6(L2)6] Metal-Ligand “Cylinder”

Cited by 89 publications

References 9 publications

A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand

A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand

Elaborate Metallosupramolecular Architectures through Desymmetrization Self-assembly of Symmetric Building Blocks

Self-Assembly of Antiferromagnetically-Coupled Copper(II) Supramolecular Architectures with Diverse Structural Complexities

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Self-Assembly of a Three-Dimensional [Ga6(L2)6] Metal-Ligand “Cylinder”

Cited by 89 publications

References 9 publications

A Zig‐Zag [MnII4] Cluster from a Novel Bis(β‐diketonate) Ligand

A Zig‐Zag [MnII4] Cluster from a Novel Bis(β‐diketonate) Ligand

Elaborate Metallosupramolecular Architectures through Desymmetrization Self-assembly of Symmetric Building Blocks

Self-Assembly of Antiferromagnetically-Coupled Copper(II) Supramolecular Architectures with Diverse Structural Complexities

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A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand

A Zig‐Zag [Mn^II₄] Cluster from a Novel Bis(β‐diketonate) Ligand