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Hokimoto Y, Nakamura T. Synthesis of a macrocyclic oligomer of pyridylbenzoxazole utilizing dynamic covalent bonds and its unsymmetric conversion. Chem Commun (Camb) 2024; 60:1281-1284. [PMID: 38196391 DOI: 10.1039/d3cc06216c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
A new unsymmetric macrocycle was synthesized by an effective and high yield 3-step synthesis, which was composed of macrocyclization, irreversible conversion, and desymmetrization. The dynamic nature of imine bonds as well as selective conversion based on strain release were utilized. Moreover, the unsymmetric macrocycle formed an interesting bivalve-like 2 : 1 complex with zinc.
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Affiliation(s)
- Yuya Hokimoto
- Degree Programs in Pure and Applied Sciences, Graduate School of Science and Technology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan
| | - Takashi Nakamura
- Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
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Nakamura T, Watanabe S. Site-Selective Ligand Bridging among Multiple Internal Coordination Sites of a Metallomacrocycle and Its Conformational Regulation. Inorg Chem 2023; 62:12886-12894. [PMID: 37530452 DOI: 10.1021/acs.inorgchem.3c01571] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Metallomacrocycles with internal coordination sites have a high potential to precisely control the positions of the guest ligands and the overall shape of the assemblies by utilizing the directionality and reversibility of the coordination bonds. However, when such coordinative hosts possess multiple coordination sites, it was difficult to control to which coordination sites the incoming guest ligands bind, because such systems often result in a random, uncontrolled mixture. The metallomacrocycle that we now report, a hexanuclear palladium complex of hexapap possessing six internal coordination sites, can take two different conformations depending on the guests. One is an Alternate conformation, in which six coordination sites of pap alternatively point to Up-Down-Up-Down-Up-Down. The other is a Twisted conformation, in which the coordination sites direct Up-Middle-Down-Up-Middle-Down. Interestingly, linear ditopic α,ω-diamines are captured in three distinct cross-linking modes, and regulations between the two macrocyclic conformations have been realized by the lengths of the diamines. Furthermore, the heteroleptic site-selective bridging of two kinds of diamines has been achieved. It has been demonstrated that a slight difference in the diamine lengths leads to a significant change in the structure and selection of the produced host-guest macrocyclic complexes.
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Affiliation(s)
- Takashi Nakamura
- Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8571, Ibaraki, Japan
| | - Satoru Watanabe
- Degree Programs in Pure and Applied Sciences, Graduate School of Science and Technology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8571, Ibaraki, Japan
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Guajardo Maturana R, Ortolan AO, Rodríguez-Kessler PL, Caramori GF, Parreira RLT, Muñoz-Castro A. Nature of hydride and halide encapsulation in Ag 8 cages: insights from the structure and interaction energy of [Ag 8(X){S 2P(O iPr) 2} 6] + (X = H -, F -, Cl -, Br -, I -) from relativistic DFT calculations. Phys Chem Chem Phys 2021; 24:452-458. [PMID: 34897316 DOI: 10.1039/d1cp04249a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unraveling the different contributing terms to an efficient anion encapsulation is a relevant issue for further understanding of the underlying factors governing the formation of endohedral species. Herein, we explore the favorable encapsulation of hydride and halide anions in the [Ag8(X){S2P(OPr)2}6]+ (X- = H, 1, F, 2, Cl, 3, Br, 4, and, I, 5) series on the basis of relativistic DFT-D level of theory. The resulting Ag8-X interaction is sizable, which decreases along the series: -232.2 (1) > -192.1 (2) > -165.5 (3) > -158.0 (4) > -144.2 kcal mol-1 (5), denoting a more favorable inclusion of hydride and fluoride anions within the silver cage. Such interaction is mainly stabilized by the high contribution from electrostatic type interactions (80.9 av%), with a lesser contribution from charge-transfer (17.4 av%) and London type interactions (1.7 av%). Moreover, the ionic character of the electrostatic contributions decreases from 90.7% for hydride to 68.6% for the iodide counterpart, in line with the decrease in hardness according to the Pearson's acid-base concept (HSAB) owing to the major role of higher electrostatic interaction terms related to the softer (Lewis) bases. Lastly, the [Ag8{S2P(OPr)2}6]2+ cluster is able to adapt its geometry in order to maximize the interaction towards respective monoatomic anion, exhibiting structural flexibility. Such insights shed light on the physical reasoning necessary for a better understanding of the different stabilizing and destabilizing contributions related to metal-based cavities towards favorable incorporation of different monoatomic anions.
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Affiliation(s)
- Raul Guajardo Maturana
- Universidad SEK, Facultad de Ciencias de la Salud, Instituto de Investigación Interdisciplinaren Ciencias Biomédicas SEK (I3CBSEK) Chile, Fernando Manterola 0789, Providencia, Santiago, Chile
| | - Alexandre O Ortolan
- Departamento de Química, Universidade Federal de Santa Catarina, Campus Universitário Trindade, CP 476, Florianópolis, SC, 88040-900, Brazil.
| | - Peter L Rodríguez-Kessler
- Laboratorio de Química Inorgánica y Materiales Moleculares, Facultad de Ingenieria, Universidad Autonoma de Chile, Llano Subercaceaux 2801, San Miguel, Santiago, Chile.
| | - Giovanni F Caramori
- Departamento de Química, Universidade Federal de Santa Catarina, Campus Universitário Trindade, CP 476, Florianópolis, SC, 88040-900, Brazil.
| | - Renato L T Parreira
- Núcleo de Pesquisa em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, 14404-600, Brazil.
| | - Alvaro Muñoz-Castro
- Laboratorio de Química Inorgánica y Materiales Moleculares, Facultad de Ingenieria, Universidad Autonoma de Chile, Llano Subercaceaux 2801, San Miguel, Santiago, Chile.
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