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Akintayo DC, Munzeiwa WA, Jonnalagadda SB, Omondi B. Ring-opening polymerization of lactides and ε-caprolactone catalyzed by Zn(II) aryl carboxylate complexes supported by 4-pyridinyl schiff base ligands. Heliyon 2023; 9:e13514. [PMID: 36846710 PMCID: PMC9950825 DOI: 10.1016/j.heliyon.2023.e13514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/26/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023] Open
Abstract
Synthesis and catalytic studies of aryl carboxylate Zn (II) complexes is reported. Reaction of substituted (E)-N-phenyl-1-(pyridin-4-yl)methanimine with a methanolic solution of Zn(CH3COO)2 and substituted aryl carboxylate co-ligands gave heteroleptic Zn(II) complexes; [Zn(C6H5COO)2(L1)]2 (1), [Zn(C7H7COO)2(L1)]2 (2), [Zn (4-F-C6H4COO)2(L1)]2 (3), [Zn(C6H5COO)2(L2)]2 (4), [Zn(C7H7COO)2(L2)]2 (5), [Zn (4-F-C6H4COO)2(L2)]2 (6), [Zn(C6H5COO)2(L3)]2 (7), [Zn(C7H7COO)2(L3)]2 (8), [Zn (4-F-C6H4COO)2(L3)]2 (9). The molecular structures of complexes 1 and 4 are dinuclear with the zinc atom in complex 1 adopting a distorted trigonal bipyramidal geometry in a bi-metallacycle while complex 4 is square pyramidal where all four benzoate ligands bridge the zinc metals in a paddle wheel arrangement. All complexes successfully initiated mass/bulk ring-opening polymerization (ROP) of ϵ-caprolactone (ϵ-CL) and lactides (LAs) monomers with or without alcohol co-initiators at elevated temperatures. Complexes 1, 4 and 6 containing the unsubstituted benzoate co-ligands were the most active in their triad; with complex 4 being the most active (k app) of 0.3450 h-1. The physicochemical properties of the polymerization products of l-lactide and rac-lactide in toluene revealed melting temperatures (Tm) between 116.58 °C and 188.03 °C, and decomposition temperatures between 278.78 °C and 331.32 °C suggestive of an isotactic PLA with a metal capped end.
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Affiliation(s)
- Damilola C. Akintayo
- School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Wisdom A. Munzeiwa
- School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
- Chemistry Department, Bindura University of Science Education, Private Bag 1020, Bindura, Zimbabwe
| | - Sreekantha B. Jonnalagadda
- School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Bernard Omondi
- School of Chemistry & Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
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2
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Bongoza U, Zamisa SJ, Munzeiwa WA, Omondi B. Silver(I) complexes of
N,N′
‐diarylformamidine ligands: Synthesis, crystal structures, and in
vitro
antibacterial studies. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Unathi Bongoza
- School of Chemistry & Physics, University of KwaZulu‐Natal, Westville Campus Durban South Africa
| | - Sizwe J. Zamisa
- School of Chemistry & Physics, University of KwaZulu‐Natal, Westville Campus Durban South Africa
| | - Wisdom A. Munzeiwa
- School of Chemistry & Physics, University of KwaZulu‐Natal, Westville Campus Durban South Africa
- Chemistry Department Bindura University of Science Education Bindura Zimbabwe
| | - Bernard Omondi
- School of Chemistry & Physics, University of KwaZulu‐Natal, Westville Campus Durban South Africa
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3
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Akintayo DC, Munzeiwa WA, Jonnalagadda SB, Omondi B. Influence of nuclearity and coordination geometry on the catalytic activity of Zn(II) carboxylate complexes in ring-opening polymerization of ε-caprolactone and lactides. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2021.120715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Stereoselective homo- and co-polymerization of lactides and ε-caprolactone catalysed by highly active racemic zinc(II) pyridyl complexes. TRANSIT METAL CHEM 2022. [DOI: 10.1007/s11243-022-00493-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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N3/4-pyridinyl Schiff base copper(II) benzoate complexes: synthesis, crystal structures and ring-opening polymerization studies. TRANSIT METAL CHEM 2022. [DOI: 10.1007/s11243-022-00494-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Akintayo DC, Munzeiwa WA, Jonnalagadda SB, Omondi B. Ring-opening polymerization of cyclic esters by 3- and 4-pyridinyl Schiff base Zn(II) and Cu(II) paddlewheel complexes: kinetic, mechanistic and tacticity studies. ARAB J CHEM 2021. [DOI: 10.1016/j.arabjc.2021.103313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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7
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Madajska K, Szymańska IB. New Volatile Perfluorinated Amidine-Carboxylate Copper(II) Complexes as Promising Precursors in CVD and FEBID Methods. MATERIALS (BASEL, SWITZERLAND) 2021; 14:3145. [PMID: 34201158 PMCID: PMC8230148 DOI: 10.3390/ma14123145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/05/2022]
Abstract
In the present study, we have synthesised and characterised newly copper(II) complexes with the general formula [Cu2(NH2(NH=)CC2F5)2(µ-O2CRF)4], where RF = CF3, C2F5, C3F7, C4F9. Infrared spectroscopy, mass spectrometry with electron ionisation (EI MS), and density-functional theory (DFT) calculations were used to confirm compounds' composition and structure. The volatility of the compounds was studied using thermal analysis (TGA), EI MS mass spectrometry, variable temperature infrared spectroscopy (VT IR), and sublimation experiments. Research has revealed that these compounds are the source of metal carriers in the gas phase. The thermal decomposition mechanism over reduced pressure was proposed. TGA studies demonstrated that copper transfer to the gaseous phase occurs even at atmospheric pressure. Two selected complexes [Cu2(NH2(NH=)CC2F5)2(µ-O2CC2F5)4] and [Cu2(NH2(NH=)CC2F5)2(µ-O2CC3F7)4] were successful used as chemical vapour deposition precursors. Copper films were deposited with an evaporation temperature of 393 K and 453 K, respectively, and a decomposition temperature in the range of 573-633 K without the use of hydrogen. The microscopic observations made to investigate the interaction of the [Cu2(NH2(NH=)CC2F5)2(µ-O2CC2F5)4] with the electron beam showed that the ligands are completely lost under transmission electron microscopy analysis conditions (200 keV), and the final product is copper(II) fluoride. In contrast, the beam energy in scanning electron microscopy (20 keV) was insufficient to break all coordination bonds. It was shown that the Cu-O bond is more sensitive to the electron beam than the Cu-N bond.
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Affiliation(s)
| | - Iwona Barbara Szymańska
- Department of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland;
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8
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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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9
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Zamisa SJ, Bongoza U, Omondi B. Predicting molecular isomerism of symmetrical and unsymmetrical N, N′-diphenyl formamidines in the solid-state: crystal structure, Hirshfeld surface analysis, pairwise interaction energy, and Δ Hfusion and Δ Sfusion correlations. CrystEngComm 2021. [DOI: 10.1039/d1ce00458a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Correlating molecular isomerism of N,N′-diphenylformamidine derivatives in the solid state with molecular pairwise interaction energies, experimental enthalpy and entropy of fusion.
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Affiliation(s)
- Sizwe J. Zamisa
- School of Chemistry and Physics
- University of Kwazulu-Natal
- Durban 4000
- South Africa
| | - Unathi Bongoza
- School of Chemistry and Physics
- University of Kwazulu-Natal
- Durban 4000
- South Africa
| | - Bernard Omondi
- School of Chemistry and Physics
- University of Kwazulu-Natal
- Pietermaritzburg
- South Africa
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10
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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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11
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Schäfer PM, Dankhoff K, Rothemund M, Ksiazkiewicz AN, Pich A, Schobert R, Weber B, Herres‐Pawlis S. Towards New Robust Zn(II) Complexes for the Ring-Opening Polymerization of Lactide Under Industrially Relevant Conditions. ChemistryOpen 2019; 8:1020-1026. [PMID: 31384524 PMCID: PMC6664153 DOI: 10.1002/open.201900199] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/25/2019] [Indexed: 12/02/2022] Open
Abstract
The synthesis of bio-based and biodegradable plastics is a hot topic in research due to growing environmental problems caused by omnipresent plastics. As a result, polylactide, which has been known for years, has seen a tremendous increase in industrial production. Nevertheless, the manufacturing process using the toxic catalyst Sn(Oct)2 is very critical. As an alternative, five zinc acetate complexes have been synthesized with Schiff base-like ligands that exhibit high activity in the ring-opening polymerization of non-purified lactide. The systems bear different side arms in the ligand scaffold. The influence of these substituents has been analyzed. For a detailed description of the catalytic activities, the rate constants k app and k p were determined using in-situ Raman spectroscopy at a temperature of 150 °C. The polymers produced have molar masses of up to 71 000 g mol-1 and are therefore suitable for a variety of applications. Toxicity measurements carried out for these complexes proved the nontoxicity of the systems.
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Affiliation(s)
- Pascal M. Schäfer
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Katja Dankhoff
- Department of Chemistry, Inorganic Chemistry IVUniversität BayreuthUniversitätsstr. 3095440BayreuthGermany
| | - Matthias Rothemund
- Department of Chemistry, Organic Chemistry IUniversität BayreuthUniversitätsstr. 3095440BayreuthGermany
| | - Agnieszka N. Ksiazkiewicz
- Functional and Interactive Polymers, Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
- DWI – Leibniz Institute for Interactive Materials e.V.Forckenbeckstr. 5052074AachenGermany
- Aachen Maastricht Institute for Biobased Materials (AMIBM)Maastricht UniversityBrightlands Chemelot Campus, Urmonderbaan 226167 RDGeleenThe Netherlands
| | - Andrij Pich
- Functional and Interactive Polymers, Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
- DWI – Leibniz Institute for Interactive Materials e.V.Forckenbeckstr. 5052074AachenGermany
- Aachen Maastricht Institute for Biobased Materials (AMIBM)Maastricht UniversityBrightlands Chemelot Campus, Urmonderbaan 226167 RDGeleenThe Netherlands
| | - Rainer Schobert
- Department of Chemistry, Organic Chemistry IUniversität BayreuthUniversitätsstr. 3095440BayreuthGermany
| | - Birgit Weber
- Department of Chemistry, Inorganic Chemistry IVUniversität BayreuthUniversitätsstr. 3095440BayreuthGermany
| | - Sonja Herres‐Pawlis
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152074AachenGermany
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