1
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Glenister MA, Frese JWA, Elsegood MRJ, Canaj AB, Brechin EK, Redshaw C. Reaction of Ph 2C(X)(CO 2H) (X = OH, NH 2) with [VO(OR) 3] (R = Et, nPr): structure, magnetic susceptibility and ROP capability. Dalton Trans 2024; 53:5351-5355. [PMID: 38444301 DOI: 10.1039/d4dt00078a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Reaction of [VO(OR)3] (R = Et, nPr) with 2,2'-diphenylglycine afforded the alkoxide-bridged dimers {[VO(OR)(μ-OR)][Ph2C(NH2)(CO2)]}2, whereas use of benzilic acid, in the presence of alkali metals, afforded 16-membered metallocycles {V8(O)4M(OR)8[Ph2C(OH)(CO2)]12} (M = <1 Na, K). For the ring systems, magnetic susceptibility data is consistent with mixed-valence vanadium with an average oxidation state of 3.5. The dimer and ring systems are capable of the ring opening polymerisation (ROP) of ε-caprolactone under N2, air, or as melts affording mostly low to medium molecular weight cyclic and linear products.
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Affiliation(s)
- Mollie A Glenister
- Plastics Collaboratory, Chemistry, School of Natural Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Josef W A Frese
- Plastics Collaboratory, Chemistry, School of Natural Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Mark R J Elsegood
- Plastics Collaboratory, Chemistry, School of Natural Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Angelos B Canaj
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Euan K Brechin
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Carl Redshaw
- Chemistry Department, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK
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2
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Sachdeva G, Bamal Y, Ladan A, Tiwari OS, Rawat V, Yadav P, Verma VP. Calixarene-Metal Complexes in Lactide Polymerization: The Story so Far. ACS OMEGA 2023; 8:13479-13491. [PMID: 37091416 PMCID: PMC10116533 DOI: 10.1021/acsomega.2c08028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
Polylactide synthetic procedures have lately gained attention, possibly due to their biocompatibility and the environmental problems associated with fossil-fuel-based polymers. Polylactides can be obtained from natural sources such as cassava, corn, and sugar beet, and polylactides can be manufactured in a laboratory using a variety of processes that begin with lactic acid or lactide. One of the most effective synthetic pathways is through a Lewis acid catalyzed ring-opening polymerization of lactides to obtain a well-defined polymer. In this regard, calixarenes, because of their easy functionalization and tunable properties, have been widely considered to be a suitable 3D molecular scaffold for new metal complexes that can be used for lactide polymerization. This review summarizes the progress made in applying some metal-calixarene complexes in the ring-opening polymerization of lactide.
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Affiliation(s)
- Garima Sachdeva
- Amity
School of Applied Sciences, Amity University
Haryana, Gurugram 122412, India
| | - Yogita Bamal
- Amity
School of Applied Sciences, Amity University
Haryana, Gurugram 122412, India
| | - Ankit Ladan
- Amity
School of Applied Sciences, Amity University
Haryana, Gurugram 122412, India
| | - Om Shanker Tiwari
- The
Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Varun Rawat
- Amity
School of Applied Sciences, Amity University
Haryana, Gurugram 122412, India
- Faculty
of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Email for V.R.:
| | - Priyanka Yadav
- Department
of Chemistry, Banasthali University, Banasthali Newai 304022, India
| | - Ved Prakash Verma
- Department
of Chemistry, Banasthali University, Banasthali Newai 304022, India
- Email for V.P.V.:
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3
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Ring Opening Polymerization of Lactides and Lactones by Multimetallic Titanium Complexes Derived from the Acids Ph2C(X)CO2H (X = OH, NH2). Catalysts 2022. [DOI: 10.3390/catal12090935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The reactions of the titanium alkoxide [Ti(OR)4] (R = Me, nPr, iPr, tBu) with the acids 2,2’-Ph2C(X)(CO2H), where X = OH and NH2, i.e., benzilic acid (2,2’-diphenylglycolic acid, L1H2), and 2,2’-diphenylglycine (L2H3), have been investigated. The variation of the reaction stoichiometry allows for the isolation of mono-, bi-, tri or tetra-metallic products, the structures of which have been determined by X-ray crystallography. The ability of the resulting complexes to act as catalysts for the ring opening polymerization (ROP) of ε-caprolactone (ε-CL) and r-lactide (r-LA) has been investigated. In the case of ε-CL, all catalysts except that derived from [Ti(OnPr)4] and L2H3, i.e., 7, exhibited an induction period of between 60 and 285 min, with 7 exhibiting the best performance (>99% conversion within 6 min). The PCL products are moderate- to high-molecular weight polymers. For r-LA, systems 1, 3, 4 and 7 afforded conversions of ca. 90% or more, with 4 exhibiting the fastest kinetics. The molecular weights for the PLA are somewhat higher than those of the PCL, with both cyclic and linear PLA products (end groups of OR/OH) identified. Comparative studies versus the [Ti(OR)4] starting materials were conducted, and although high conversions were achieved, the control was poor.
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4
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Zn(II) pyridinyl amine complexes, synthesis and crystal structure studies: A comparative study of the effect of nuclearity and benzoate type on the ring-opening polymerization of cyclic esters. Polyhedron 2022. [DOI: 10.1016/j.poly.2021.115589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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5
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Zhang X, Prior TJ, Redshaw C. Niobium and Tantalum complexes derived from the acids Ph 2C(X)CO 2H (X = OH, NH 2): synthesis, structure and ROP capability. NEW J CHEM 2022. [DOI: 10.1039/d2nj02527b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tetranuclear [M4(OEt)8(L1)4(μ-O)2] and dinuclear [M2(OEt)4(L2H2)4(μ-O)] complexes (M = Nb, Ta) derived from benzilic acid (L1H2) and diphenylglycine (L2H3) have been structurally characterized and are capable of the ROP of μ-caprolactone and rac-lactide.
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Affiliation(s)
- Xin Zhang
- Plastics Collaboratory, Department of Chemistry, The University of Hull, Cottingham Rd, Hull HU6 7RX, UK
| | - Timothy J. Prior
- Plastics Collaboratory, Department of Chemistry, The University of Hull, Cottingham Rd, Hull HU6 7RX, UK
| | - Carl Redshaw
- Plastics Collaboratory, Department of Chemistry, The University of Hull, Cottingham Rd, Hull HU6 7RX, UK
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6
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Santoro O, Elsegood MRJ, Teat SJ, Yamato T, Redshaw C. Lithium calix[4]arenes: structural studies and use in the ring opening polymerization of cyclic esters. RSC Adv 2021; 11:11304-11317. [PMID: 35423659 PMCID: PMC8695813 DOI: 10.1039/d1ra00175b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/08/2021] [Indexed: 01/07/2023] Open
Abstract
We have structurally characterized a number of lithiated calix[4]arenes, where the bridge in the calix[4]arene is thia (–S–, LSH4), sulfinyl (–SO–, LSOH4), sulfonyl (–SO2–, LSO2H4), dimethyleneoxa (–CH2OCH2–, LCOCH4) or methylene (–CH2–, LH4). In the case of L4SH4, interaction with LiOtBu led to the isolation of the complex [Li8(L4S)2(THF)4]·5THF (1·5THF), whilst similar interaction of L4SOH4 led to the isolation of [Li6(L4SOH)2(THF)2]·5(THF) (2·5THF). Interestingly, the mixed sulfinyl/sulfonyl complexes [Li8(calix[4]arene(SO)(SO2)(SO1.68)2)2(THF)6]·8(THF) (3·8THF) and [Li5Na(LSO/3SO2H)2(THF)5]·7.5(THF) (4·7.5(THF) have also been characterized. Interaction of LiOtBu with LSO2H4 and LCOCH4 afforded [Li5L4SO2(OH)(THF)4]·2THF (5·2THF) and [Li6(LCOC)2(HOtBu)2]·0.78THF·1.22hexane (6·0.78THF·1.22hexane), respectively. In the case of LH4, reaction with LiOtBu in THF afforded a monoclinic polymorph [LH2Li2(thf)(OH2)2]·3THF (7·3THF) of a known triclinic form of the complex, whilst reaction of the de-butylated analogue of LH4, namely de-BuLH4, afforded a polymeric chain structure {[Li5(de-BuL)(OH)(NCMe)3]·2MeCN}n (8·2MeCN). For comparative catalytic studies, the complex [Li6(LPr)2(H2O)2]·hexane (9 hexane), where LPr2H2 = 1,3-di-n-propyloxycalix[4]areneH2, was also prepared. The molecular crystal structures of 1–9 are reported, and their ability to act as catalysts for the ring opening (co-)/polymerization (ROP) of the cyclic esters ε-caprolactone, δ-valerolactone, and rac-lactide has been investigated. In most of the cases, complex 6 outperformed the other systems, allowing for higher conversions and/or greated polymer Mn. Novel Li-calix[n]arene complexes (n = 3, 4) having (–S–), (–SO–), (–SO2–), (–CH2OCH2–) or (–CH2–) bridges have been synthesized and fully characterized. Their catalytic activity in the ring opening polymerization of lactones has been studied.![]()
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Affiliation(s)
- Orlando Santoro
- Plastics Collaboratory
- Department of Chemistry
- University of Hull
- Hull
- UK
| | | | - Simon J. Teat
- Advanced Light Source
- Berkeley National Laboratory
- Berkeley
- USA
| | - Takehiko Yamato
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Saga University
- Saga-shi
- Japan
| | - Carl Redshaw
- Plastics Collaboratory
- Department of Chemistry
- University of Hull
- Hull
- UK
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7
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Collins J, Santoro O, Prior TJ, Chen K, Redshaw C. Rare-earth metal complexes derived from the acids Ph2C(X)CO2H (X= OH, NH2): Structural and ring opening polymerization (ROP) studies. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Alshamrani AF, Prior TJ, Burke BP, Roberts DP, Archibald SJ, Higham LJ, Stasiuk G, Redshaw C. Water-Soluble Rhenium Phosphine Complexes Incorporating the Ph 2C(X) Motif (X = O -, NH -): Structural and Cytotoxicity Studies. Inorg Chem 2020; 59:2367-2378. [PMID: 31984731 DOI: 10.1021/acs.inorgchem.9b03239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction of [ReOCl3(PPh3)2] or [ReO2I(PPh3)2] with 2,2'-diphenylglycine (dpgH2) in refluxing ethanol afforded the air-stable complex [ReO(dpgH)(dpg)(PPh3)] (1). Treatment of [ReO(OEt)I2(PPh3)2] with 1,2,3-triaza-7-phosphaadamantane (PTA) afforded the complex [ReO(OEt)I2(PTA)2] (2). Reaction of [ReOI2(PTA)3] with dpgH2 led to the isolation of the complex [Re(NCPh2)I2(PTA)3]·0.5EtOH (3·0.5EtOH). A similar reaction but using [ReOX2(PTA)3] (X = Cl, Br) resulted in the analogous halide complexes [Re(NCPh2)Cl2(PTA)3]·2EtOH (4·2EtOH) and [Re(NCPh2)(PTA)3Br2]·1.6EtOH (5·1.6EtOH). Using benzilic acid (2,2'-diphenylglycolic acid, benzH) with 2 afforded the complex [ReO(benz)2(PTA)][PTAH]·EtOH (6·EtOH). The potential for the formation of complexes using radioisotopes with relatively short half-lives suitable for nuclear medicine applications by developing conditions for [Re(NCPh2)(dpg)I(PTA)3] (7)[ReO4]- in a 4 h time scale was investigated. A procedure for the technetium analog of complex [Re(NCPh2)I2(PTA)3] (3) from 99mTc[TcO4]- was then investigated. The molecular structures of 1-7 are reported; complexes 3-7 have been studied using in vitro cell assays (HeLa, HCT116, HT-29, and HEK 293) and were found to have IC50 values in the range of 29-1858 μM.
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Affiliation(s)
- Abdullah F Alshamrani
- Department of Chemistry & Biochemistry , University of Hull , Cottingham Road , Hull HU6 7RX , U.K.,Department of Biomedical Sciences , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - Timothy J Prior
- Department of Chemistry & Biochemistry , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - Benjamin P Burke
- Positron Emission Tomography Research Centre , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - David P Roberts
- Positron Emission Tomography Research Centre , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - Stephen J Archibald
- Department of Biomedical Sciences , University of Hull , Cottingham Road , Hull HU6 7RX , U.K.,Positron Emission Tomography Research Centre , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - Lee J Higham
- School of Natural & Environmental Sciences , Newcastle University , Newcastle upon Tyne NE1 7RU , U.K
| | - Graeme Stasiuk
- Department of Biomedical Sciences , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
| | - Carl Redshaw
- Department of Chemistry & Biochemistry , University of Hull , Cottingham Road , Hull HU6 7RX , U.K
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9
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Yu X, Zhang C, Wang Z. Controlled Polymerization of ϵ‐Caprolactone using Aluminum and Zinc Complexes with Iminophosphorane Ligands. ChemistrySelect 2020. [DOI: 10.1002/slct.201904185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xiaofeng Yu
- School of Materials and Chemical EngineeringBengbu University Bengbu, Anhui 233030 P. R. China
| | - Cheng Zhang
- School of Engineering and TechnologyBeijing Normal University Zhuhai Campus, Zhuhai Guangdong 510000 P. R. China
| | - Zhongxia Wang
- Department of ChemistryUniversity of Science and Technology of China, Hefei Anhui 230026 P. R. of China
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10
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Gao J, Zhu D, Zhang W, Solan GA, Ma Y, Sun WH. Recent progress in the application of group 1, 2 & 13 metal complexes as catalysts for the ring opening polymerization of cyclic esters. Inorg Chem Front 2019. [DOI: 10.1039/c9qi00855a] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review focuses on recent developments concerned with the use of well-defined main group complexes as (pre-)catalysts for the ROP of cyclic esters to give aliphatic polyesters; factors influencing catalytic activity, selectivity and polymer properties are all discussed.
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Affiliation(s)
- Jiahao Gao
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Dongzhi Zhu
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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11
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Cols JMEP, Hill VG, Williams SK, McIntosh RD. Aggregated initiators: defining their role in the ROP of rac-lactide. Dalton Trans 2018; 47:10626-10635. [PMID: 29796503 DOI: 10.1039/c8dt01229f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Reported examples of aggregated initiators for the ring-opening polymerisation (ROP) of lactide often lack detailed investigations as to the nature of the active species, making it difficult to reconcile ligand design with performance. Here, we offer additional stability to the polynuclear titanium complexes, TiL(OiPr) (L = 9-14), through a bridging carboxylate anchored to the supporting amine bis(phenolate) ligands. An in-depth study of solution-state behaviour determined the process of assembly was driven by interactions between the carboxylate and a vacant site on a neighbouring titanium centre. Furthermore, we establish that mononuclear units form dynamic mixtures of polynuclear aggregates, with a clear relationship between nuclearity of the aggregates and the steric bulk on the ligand. Smaller aggregates displayed increased activity towards the ROP of rac-lactide. Furthermore, addition of a chiral centre, on the ligand framework, was investigated as a route to influence the selectivity of the polymerisation via easily-accessible initiators.
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Affiliation(s)
- Jean-Marie E P Cols
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
| | - Victoria G Hill
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
| | - Stella K Williams
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
| | - Ruaraidh D McIntosh
- Institute of Chemical Sciences, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK.
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