Ring opening polymerization ofd,l-lactide and ε-caprolactone catalysed by (pyrazol-1-yl)copper(ii) carboxylate complexes

Divambal Appavoo; Lara C. Spencer; Ilia A. Guzei; Carlos J. Gómez-García; Juanita L. van Wyk; James Darkwa

doi:10.1039/d1ra00339a

Ring opening polymerization ofd,l-lactide and ε-caprolactone catalysed by (pyrazol-1-yl)copper(ii) carboxylate complexes

Divambal Appavoo
, Lara C. Spencer
, Ilia A. Guzei
, Carlos J. Gómez-García
, Juanita L. van Wyk
, James Darkwa

Chemical Sciences

Research output: Contribution to journal › Article › peer-review

10 Citations (Scopus)

Abstract

1,2-Bis{(3,5-dimethylpyrazol-1-yl)methyl}benzene (L) reacts with [Cu(OAc)₂] and C₆H₅COOH, 4-OH-C₆H₄COOH, 2-Cl-C₆H₄COOH and (3,5-NO₂)₂-C₆H₃COOH to afford the copper complexes [Cu₂(C₆H₅COO)₄(L)₂] (1), [Cu₂(4-OH-C₆H₄COO)₄(L)₂] (2), [Cu₂(2-Cl-C₆H₄COO)₄(L)₂]_n(3) and [Cu{(3,5-NO₂)₂-C₆H₃COO}₂L]_n(4) which are characterised by IR, mass spectrometry, elemental analyses, and X-ray crystallography. The structural data revealed two geometries that are adopted by the complexes: (i) paddle wheel in1,2·7H₂O,3and (ii) regular chains in3and4. Magnetic studies show strong antiferromagnetic couplings in the paddle wheel complexes and a weak antiferromagnetic coupling in the monometallic chain one. Catalysis studies performed with these complexes (1-4) showed that they initiate ring opening polymerization (ROP) of ε-caprolactone (ε-CL) under solvent-free conditions andd,l-lactide in toluene at elevated temperatures. Polycaprolactone (PCL) and poly(d,l-lactide) (PLA) obtained from the polymerization reactions are of low molecular weights (858 for PCL and 602 Da for PLA for initiator1) and polydispersity indices (typically 2.16 for PCL and 1.64 for PLA with1as the initiator). End group analysis of the polymers, determined by MALDI-ToF MS, indicates that the polymers have benzoate, hydroxyl, methoxy and cyclic end groups.

Original language	English
Pages (from-to)	13475-13485
Number of pages	11
Journal	RSC Advances
Volume	11
Issue number	22
DOIs	https://doi.org/10.1039/d1ra00339a
Publication status	Published - 12 Apr 2021

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering

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10.1039/d1ra00339a

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@article{683fc29973834704ad6a607f5d33ee58,

title = "Ring opening polymerization ofd,l-lactide and ε-caprolactone catalysed by (pyrazol-1-yl)copper(ii) carboxylate complexes",

abstract = "1,2-Bis\{(3,5-dimethylpyrazol-1-yl)methyl\}benzene (L) reacts with [Cu(OAc)2] and C6H5COOH, 4-OH-C6H4COOH, 2-Cl-C6H4COOH and (3,5-NO2)2-C6H3COOH to afford the copper complexes [Cu2(C6H5COO)4(L)2] (1), [Cu2(4-OH-C6H4COO)4(L)2] (2), [Cu2(2-Cl-C6H4COO)4(L)2]n(3) and [Cu\{(3,5-NO2)2-C6H3COO\}2L]n(4) which are characterised by IR, mass spectrometry, elemental analyses, and X-ray crystallography. The structural data revealed two geometries that are adopted by the complexes: (i) paddle wheel in1,2·7H2O,3and (ii) regular chains in3and4. Magnetic studies show strong antiferromagnetic couplings in the paddle wheel complexes and a weak antiferromagnetic coupling in the monometallic chain one. Catalysis studies performed with these complexes (1-4) showed that they initiate ring opening polymerization (ROP) of ε-caprolactone (ε-CL) under solvent-free conditions andd,l-lactide in toluene at elevated temperatures. Polycaprolactone (PCL) and poly(d,l-lactide) (PLA) obtained from the polymerization reactions are of low molecular weights (858 for PCL and 602 Da for PLA for initiator1) and polydispersity indices (typically 2.16 for PCL and 1.64 for PLA with1as the initiator). End group analysis of the polymers, determined by MALDI-ToF MS, indicates that the polymers have benzoate, hydroxyl, methoxy and cyclic end groups.",

author = "Divambal Appavoo and Spencer, \{Lara C.\} and Guzei, \{Ilia A.\} and G{\'o}mez-Garc{\'i}a, \{Carlos J.\} and \{van Wyk\}, \{Juanita L.\} and James Darkwa",

note = "Publisher Copyright: {\textcopyright} The Royal Society of Chemistry 2021.",

year = "2021",

month = apr,

day = "12",

doi = "10.1039/d1ra00339a",

language = "English",

volume = "11",

pages = "13475--13485",

journal = "RSC Advances",

issn = "2046-2069",

publisher = "Royal Society of Chemistry",

number = "22",

}

TY - JOUR

T1 - Ring opening polymerization ofd,l-lactide and ε-caprolactone catalysed by (pyrazol-1-yl)copper(ii) carboxylate complexes

AU - Appavoo, Divambal

AU - Spencer, Lara C.

AU - Guzei, Ilia A.

AU - Gómez-García, Carlos J.

AU - van Wyk, Juanita L.

AU - Darkwa, James

PY - 2021/4/12

Y1 - 2021/4/12

N2 - 1,2-Bis{(3,5-dimethylpyrazol-1-yl)methyl}benzene (L) reacts with [Cu(OAc)2] and C6H5COOH, 4-OH-C6H4COOH, 2-Cl-C6H4COOH and (3,5-NO2)2-C6H3COOH to afford the copper complexes [Cu2(C6H5COO)4(L)2] (1), [Cu2(4-OH-C6H4COO)4(L)2] (2), [Cu2(2-Cl-C6H4COO)4(L)2]n(3) and [Cu{(3,5-NO2)2-C6H3COO}2L]n(4) which are characterised by IR, mass spectrometry, elemental analyses, and X-ray crystallography. The structural data revealed two geometries that are adopted by the complexes: (i) paddle wheel in1,2·7H2O,3and (ii) regular chains in3and4. Magnetic studies show strong antiferromagnetic couplings in the paddle wheel complexes and a weak antiferromagnetic coupling in the monometallic chain one. Catalysis studies performed with these complexes (1-4) showed that they initiate ring opening polymerization (ROP) of ε-caprolactone (ε-CL) under solvent-free conditions andd,l-lactide in toluene at elevated temperatures. Polycaprolactone (PCL) and poly(d,l-lactide) (PLA) obtained from the polymerization reactions are of low molecular weights (858 for PCL and 602 Da for PLA for initiator1) and polydispersity indices (typically 2.16 for PCL and 1.64 for PLA with1as the initiator). End group analysis of the polymers, determined by MALDI-ToF MS, indicates that the polymers have benzoate, hydroxyl, methoxy and cyclic end groups.

AB - 1,2-Bis{(3,5-dimethylpyrazol-1-yl)methyl}benzene (L) reacts with [Cu(OAc)2] and C6H5COOH, 4-OH-C6H4COOH, 2-Cl-C6H4COOH and (3,5-NO2)2-C6H3COOH to afford the copper complexes [Cu2(C6H5COO)4(L)2] (1), [Cu2(4-OH-C6H4COO)4(L)2] (2), [Cu2(2-Cl-C6H4COO)4(L)2]n(3) and [Cu{(3,5-NO2)2-C6H3COO}2L]n(4) which are characterised by IR, mass spectrometry, elemental analyses, and X-ray crystallography. The structural data revealed two geometries that are adopted by the complexes: (i) paddle wheel in1,2·7H2O,3and (ii) regular chains in3and4. Magnetic studies show strong antiferromagnetic couplings in the paddle wheel complexes and a weak antiferromagnetic coupling in the monometallic chain one. Catalysis studies performed with these complexes (1-4) showed that they initiate ring opening polymerization (ROP) of ε-caprolactone (ε-CL) under solvent-free conditions andd,l-lactide in toluene at elevated temperatures. Polycaprolactone (PCL) and poly(d,l-lactide) (PLA) obtained from the polymerization reactions are of low molecular weights (858 for PCL and 602 Da for PLA for initiator1) and polydispersity indices (typically 2.16 for PCL and 1.64 for PLA with1as the initiator). End group analysis of the polymers, determined by MALDI-ToF MS, indicates that the polymers have benzoate, hydroxyl, methoxy and cyclic end groups.

UR - https://www.scopus.com/pages/publications/85104239134

U2 - 10.1039/d1ra00339a

DO - 10.1039/d1ra00339a

M3 - Article

AN - SCOPUS:85104239134

SN - 2046-2069

VL - 11

SP - 13475

EP - 13485

JO - RSC Advances

JF - RSC Advances

IS - 22

ER -

Ring opening polymerization ofd,l-lactide and ε-caprolactone catalysed by (pyrazol-1-yl)copper(ii) carboxylate complexes

Abstract

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