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Lee J, Melchakova I, Nayab S, Kim K, Ko YH, Yoon M, Avramov P, Lee H. Synthesis and Characterization of Zinc(II), Cadmium(II), and Palladium(II) Complexes with the Thiophene-Derived Schiff Base Ligand. ACS OMEGA 2023; 8:6016-6029. [PMID: 36816644 PMCID: PMC9933481 DOI: 10.1021/acsomega.2c08001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/23/2023] [Indexed: 06/01/2023]
Abstract
Zn(II), Pd(II), and Cd(II) complexes, [L TH MCl 2 ] (M = Zn, Pd; X = Br, Cl) and [L TH Cd(μ-X)X] n (X = Cl, Br; n = n, 2), supported by the (E)-N 1,N 1-dimethyl-N 2-(thiophen-2-ylmethylene)ethane-1,2-diamine (L TH ) ligand are synthesized and structurally characterized. Density functional theory (DFT) electronic structure calculations and variable-temperature NMR support the presence of two conformers and a dynamic interconversion process of the minor conformer to the major one in solution. It is found that the existence of two relevant complex conformers and their respective ratios in solution depend on the central metal ions and counter ions, either Cl- or Br-. Among the two relevant conformers, a single conformer is crystallized and X-ray diffraction analysis revealed a distorted tetrahedral geometry for Zn(II) complexes, and a distorted square planar and square pyramidal geometry for Pd(II) and Cd(II) complexes, respectively. It is shown that [L TH MCl 2 ]/LiO i Pr (M = Zn, Pd) and [L TH Cd(μ-Cl)Cl] n /LiO i Pr can effectively catalyze the ring-opening polymerization (ROP) reaction of rac-lactide (rac-LA) with 94% conversion within 30 s with [L TH ZnCl 2 ]/LiO i Pr at 0 °C. Overall, hetero-enriched poly(lactic acid)s (PLAs) were provided by these catalytic systems with [L TH ZnCl 2 ]/LiO i Pr producing PLA with higher heterotactic bias (P r up to 0.74 at 0 °C).
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Affiliation(s)
- Jaegyeong Lee
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Iuliia Melchakova
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Saira Nayab
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
- Department
of Chemistry, Shaheed Benazir Bhutto University
(SBBU), Sheringal 18050, Upper Dir, Khyber Pakhtunkhwa, Islamic Republic of Pakistan
| | - Kyeonghun Kim
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Young Ho Ko
- Center
for Self-Assembly and Complexity (CSC), Institute for Basic Science
(IBS), Pohang University of Science and
Technology (POSTEC), Pohang 37673, Republic
of Korea
| | - Minyoung Yoon
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Paul Avramov
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Hyosun Lee
- Department
of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
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Effect of initiator on the catalytic performance of zinc(II) complexes supported by aminomethylquinoline and aminomethylpyridine derived ligands in stereoselective ring opening polymerization of rac-lactide. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Choe S, Lee H, Nayab S. Diverse coordination geometry of cobalt (II), zinc (II), and cadmium (II) complexes comprising
N
,
N
‐bis(1H‐pyrazol‐1‐yl)methyl)amines derivatives: Synthesis, structures, and ring opening polymerization of
rac
‐lactide. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Solhye Choe
- Department of Chemistry and Green‐Nano Materials Research Center Kyungpook National University Daegu South Korea
| | - Hyosun Lee
- Department of Chemistry and Green‐Nano Materials Research Center Kyungpook National University Daegu South Korea
| | - Saira Nayab
- Department of Chemistry Shaheed Benazir Bhutto University Sheringal Dir (U) Pakistan
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4
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Choe S, Lee H, Nayab S. Synthesis, structures, and catalytic efficiency in ring opening polymerization of rac-lactide with tridentate vs. bidentate cobalt( ii), zinc( ii), and cadmium( ii) complexes containing N-substituted N, N-bis((3,5-dimethyl-1 H-pyrazol-1-yl)methyl)amine ligands. RSC Adv 2021; 11:18840-18851. [PMID: 35478641 PMCID: PMC9033469 DOI: 10.1039/d1ra02365a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/20/2021] [Indexed: 01/09/2023] Open
Abstract
A series of Co(ii), Zn(ii), and Cd(ii) complexes supported by 1-(3,5-dimethyl-1H-pyrazol-1-yl)-N-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-N-(furan-2-ylmethyl)methanamine (LA) and N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-4-isopropylaniline (LB) were synthesized. The direct chelation of CoCl2·6H2O, ZnCl2, and CdBr2·4H2O by the ligands produced [LnMX2] (Ln = LA or LB; M = Zn or Co, with X = Cl; M = Cd, with X = Br) complexes in high yields. Structural studies revealed that [LBCoCl2] and [LBZnCl2] adopted distorted tetrahedral geometries, as LB coordinated the metal centers in a bidentate fashion, while LA coordinated the metal centers in a tridentate fashion through the nitrogen atoms of the pyrazole and amine moieties, so that [LACoCl2] and [LAZnCl2] exhibited trigonal bipyramidal geometries and [LACdBr2] a square pyramidal geometry. [LBCdBr2] has two Cd-containing structures per unit cell, whereby one Cd center adopted a distorted tetrahedral geometry and the other exhibited square bipyramidal geometry. The in situ-generated alkyl derivatives of the synthesized complexes were assessed in the ring-opening polymerization of rac-lactide. Heterotactic polylactides (PLAs) were furnished with all complexes. The [LBZnCl2]/MeLi system produced PLA with a superior heterotactic bias (Pr up to 0.94) at −25 °C. PLAs with wide-ranging polydispersity indices (1.16–2.23) and low molecular weights were produced in all cases, irrespective of the specific M(II) center and ancillary ligand utilized. Co(ii), Zn(ii), and Cd(ii) complexes supported by bis-pyrazolyl ligands were applied to the ring-opening polymerization of rac-lactide to produce heterotactic polylactides (PLAs) with superior heterotactic bias i.e. Pr up to 0.94 at −25 °C.![]()
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Affiliation(s)
- Solhye Choe
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu
- Republic of Korea
| | - Hyosun Lee
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu
- Republic of Korea
| | - Saira Nayab
- Department of Chemistry
- Shaheed Benazir Bhutto University
- Islamic Republic of Pakistan
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Cho J, Jeong JH, Lee MW, Kang YK. Interrogation of fractional crystallization behavior of a newly exploited chiral resolution method for racemic 1-(pyridin-2-yl)ethylamine via DFT-D3 calculations of cohesive energy. Inorg Chem Front 2019. [DOI: 10.1039/c9qi00523d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel chiral separation method for 1-(pyridin-2-yl)ethylamine is developed and the underlying energetics is investigated by DFT-D3.
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Affiliation(s)
- Juhyun Cho
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu 41566
- Republic of Korea
| | - Jong Hwa Jeong
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu 41566
- Republic of Korea
| | - Myung Won Lee
- Department of Chemistry
- Pukyong National University
- Busan 48513
- Republic of Korea
| | - Youn K. Kang
- Department of Chemistry
- Sangmyung University
- Seoul 03016
- Republic of Korea
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