Multiple Folding Structures Mediated by Metal Coordination of Acyclic Multidentate Ligand

Akine, Shigehisa; Morita, Yoko; Utsuno, Fumihiko; Nabeshima, Tatsuya

doi:10.1021/ic901372k

Cited by 68 publications

(24 citation statements)

References 35 publications

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“…We have already demonstrated that a binding selectivity trend of alkali metal << Zn 2+ < alkaline earth < rare earth metal ions was observed in the shorter L 1 Zn2M system [57] and related complexes [79][80][81][82][83] without chiral auxiliary. If the longer L 4 Zn3M system having a chiral auxiliary also shows a similar selectivity trend, Ba 2+ in the L 4 Zn3Ba can be efficiently replaced by La 3+ .…”

Section: Helicity Inversion By Metal Exchangementioning

confidence: 92%

Dynamic Helicity Control of Oligo(salamo)-Based Metal Helicates

Akine

2018

Inorganics

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Much attention has recently focused on helical structures that can change their helicity in response to external stimuli. The requirements for the invertible helical structures are a dynamic feature and well-defined structures. In this context, helical metal complexes with a labile coordination sphere have a great advantage. There are several types of dynamic helicity controls, including the responsive helicity inversion. In this review article, dynamic helical structures based on oligo(salamo) metal complexes are described as one of the possible designs. The introduction of chiral carboxylate ions into Zn 3 La tetranuclear structures as an additive is effective to control the P/M ratio of the helix. The dynamic helicity inversion can be achieved by chemical modification, such as protonation/deprotonation or desilylation with fluoride ion. When (S)-2-hydroxypropyl groups are introduced into the oligo(salamo) ligand, the helicity of the resultant complexes is sensitively influenced by the metal ions. The replacement of the metal ions based on the affinity trend resulted in a sequential multistep helicity inversion. Chiral salen derivatives are also effective to bias the helicity; by incorporating the gauche/anti transformation of a 1,2-disubstituted ethylene unit, a fully predictable helicity inversion system was achieved, in which the helicity can be controlled by the molecular lengths of the diammonium guests.

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Section: Helicity Inversion By Metal Exchangementioning

confidence: 92%

Dynamic Helicity Control of Oligo(salamo)-Based Metal Helicates

Akine

2018

Inorganics

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“…On the other hand, because of complex 2 is synthesized by the half-salamo ligand HL 2 , when the Zn(II) atoms coordinated to HL 2 , the conjugate system of complex 2 not change greatly compared with complex 1, which leads to the absorption spectra were almost unchanged before and after the complexation. Upon coordination of the ligand HL 2 , the absorption intensities are weakened compared with the free ligand HL 2 , which indicate that the oxime nitrogen atoms are involved in coordination with the Zn(II) atoms [37,66]. compared with the free ligand HL , which indicate that the oxime nitrogen atoms are involved in coordination with the Zn(II) atoms [37,66].…”

Section: Uv-vis Spectramentioning

confidence: 99%

“…Upon coordination of the ligand HL 2 , the absorption intensities are weakened compared with the free ligand HL 2 , which indicate that the oxime nitrogen atoms are involved in coordination with the Zn(II) atoms [37,66]. compared with the free ligand HL , which indicate that the oxime nitrogen atoms are involved in coordination with the Zn(II) atoms [37,66].…”

Section: Uv-vis Spectramentioning

confidence: 99%

Tri- and Mono-Nuclear Zinc(II) Complexes Based on Half- and Mono-Salamo Chelating Ligands

et al. 2017

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Two newly designed complexes, [Zn(L 1 )(EtOH)] (1) and [{Zn(L 2 )(OAc) 2 } 2 Zn]·CHCl 3 (2) derived from salamo and half-salamo chelating ligands (H 2 L 1 and HL 2 ) have been synthesized and characterized by elemental analyses, IR and UV-VIS spectra, fluorescence spectra, and X-ray crystallography. Complex 1 shows a slightly distorted tetragonal pyramid and forms an infinite 3D supramolecular structure. All of the Zn(II) ions in complex 2 are hexa-coordinated with slightly distorted octahedral geometries. Complex 2 possesses an infinite 2D space structure. The fluorescence titration experiments were used to characterize fluorescence properties of complexes 1 and 2. And the normalized fluorescent spectra exhibit that complexes 1 and 2 have favourable fluorescent emissions in different solvents.

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“…Especially, some substitution of atoms of the ligand with other elements often evidently improves its properties. When an O-alkyl oxime unit substitutes the imine moiety, the larger electronegativity of the O atoms is predicted to improve significantly the electronic behaviors of Salamo-type compounds, which may give rise to novel structures and better properties of the metal(II) complexes [27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Tetra-, Penta- and Hexa-Coordinated Transition Metal Complexes Constructed from Coumarin-Containing N2O2 Ligand

et al. 2018

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Three newly designed complexes, [Cu(L)]·CHCl 3 (1), [Co(L)(MeOH)]·CHCl 3 (2) and [{Ni(L)(MeOH)(PhCOO)} 2 Ni] (3) a coumarin-containing Salamo-type chelating ligand (H 2 L) have been synthesized and characterized by elemental analyses, IR and UV-VIS spectra, and X-ray crystallography. Complex 1 includes one Cu(II) atom, one completely deprotonated (L) 2− unit and one crystalling chloroform molecule, the Cu(II) atom shows a square-planar geometry. Complex 2 includes one Co(II) atom, one completely deprotonated (L) 2− unit, one coordinated methanol molecule and one crystalling chloroform molecule. The Co(II) atom is a distorted trigonal-bipyramidal geometry. While complex 3 includes three Ni(II) atoms, two completely deprotonated (L) 2− units, two benzoates and two coordinated methanol molecules. The complexes 1 and 2 are both possess three-dimensional supra-molecular structures by abundant noncovalent interactions. But, complex 3 formed a two-dimensional supra-molecular structure by intra-molecular hydrogen bonds. In addition, the antimicrobial and fluorescence properties of H 2 L and its complexes 1, 2 and 3 were also investigated.

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Multiple Folding Structures Mediated by Metal Coordination of Acyclic Multidentate Ligand

Cited by 68 publications

References 35 publications

Dynamic Helicity Control of Oligo(salamo)-Based Metal Helicates

Dynamic Helicity Control of Oligo(salamo)-Based Metal Helicates

Tri- and Mono-Nuclear Zinc(II) Complexes Based on Half- and Mono-Salamo Chelating Ligands

Tetra-, Penta- and Hexa-Coordinated Transition Metal Complexes Constructed from Coumarin-Containing N2O2 Ligand

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