Synthesis and structural studies of copper(II) complex supported by –ONNO– tetradentate ligand: Efficient catalyst for the ring-opening polymerization of lactide

Routaray, Anita; Nath, Nibedita; Mantri, Somanath; Maharana, Tungabidya; Sutar, Alekha Kumar

doi:10.1016/s1872-2067(14)60293-x

Cited by 23 publications

(6 citation statements)

References 38 publications

(43 reference statements)

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“…Numerous methods have already been exploited for the synthesis of PLA in bulk which includes direct polycondensation, 26,27 azeotropic-dehydrative condensation, melt/solid polycondensation, 28−30 and ROP . 31,32 Among the above synthesis methods, only bulk ROP has the potential to yield PLA with a high molecular weight within a short polymerization time and thus is the most preferred technique.…”

Section: Introductionmentioning

confidence: 99%

“…Synthesis of PLA can be carried out either in solution or in bulk. − However, bulk polymerization is a more favorable technique for the production of PLA on a mass scale, as the rate of polymerization is faster as compared to solution polymerization and thus, we have focussed our investigations on the ring-opening polymerization ( ROP ) of l -lactide ( LLA ) in bulk. Numerous methods have already been exploited for the synthesis of PLA in bulk which includes direct polycondensation, , azeotropic-dehydrative condensation, melt/solid polycondensation, − and ROP . , Among the above synthesis methods, only bulk ROP has the potential to yield PLA with a high molecular weight within a short polymerization time and thus is the most preferred technique.…”

Section: Introductionmentioning

confidence: 99%

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Designing of Poly(l-lactide)–Nicotine Conjugates: Mechanistic and Kinetic Studies and Thermal Release Behavior of Nicotine

et al. 2017

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The current work focuses on the ring-opening polymerization ( ROP ) of l -lactide ( LLA ) using N-heterocyclic functionalized molecules as an initiator for the synthesis of metal-free poly( l -lactide) ( PLLA ) conjugates. With this motivation, we have used a drug molecule, nicotine, having N-heterocyclic functionality as the initiator for the synthesis of PLLA conjugates. Structural characterizations carried out using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, Fourier transform infrared, and NMR establish the reacting species during polymerization in the absence of any side reactions. However, side reactions occurred because of the absence of steric hindrance when polymerization is initiated using nicotine in the presence of benzyl alcohol. Accordingly, we report here a detailed investigation on the mechanism of nicotine as an initiator and propose an anionic-based mechanism for the ROP of LLA . Studies on the kinetics parameters have been performed for the nicotine-initiated ROP of LLA and have found that polymerization proceeds with a first-order dependence on both the monomer and initiator concentrations with a low activation energy of 4.9 kcal·mol –1 . Further, thermal release studies performed by hyphenated thermogravimetric–Fourier transform infrared analysis found that nicotine is released along with reduced toxins from these synthesized PLLA –nicotine conjugates. Thus, these PLLA –nicotine conjugates can in turn open up a new era in tobacco industries for the preparation of synthetic cigarettes and also in biomedical applications for drug delivery purposes. Herein, a few preliminary experiments using another drug molecule, nicorandil, having similar N-heterocyclic functionality were also conducted to support the role of nicotine as an initiator for the synthesis of PLLA conjugates.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Designing of Poly(l-lactide)–Nicotine Conjugates: Mechanistic and Kinetic Studies and Thermal Release Behavior of Nicotine

et al. 2017

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“…Both complexes proved active in the ROP of L-lactide; although higher rates were observed for the monometallic species, the Nd-containing compound allowed for higher polymer M n and better control. An extensive investigation of the catalytic activity of complex 95 and of its phenyl-and propylene-bridged derivatives 96 and 97 was undertaken by the group of Sutar [64][65][66]. The compounds exhibited similar catalytic behavior in the ROP of L-lactide, allowing for high conversions when activated by one equiv./Cu of BnOH in CH 2 Cl 2 or toluene.…”

Section: Coppermentioning

confidence: 99%

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

2020

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“…Mid- to late d n -transition metal complexes, on the other hand, have been sparingly studied. Very few studies investigated the performance of Cr, Mn, − or Co systems. ,, Next to iron, ,− copper complexes received the highest attention. − We have reported that copper diiminopyrrolide complex 1 polymerizes rac -lactide with an isoselectivity of P m = 0.7 at room temperature (Scheme ). Isoselective stereocontrol was unprecedented for copper complexes.…”

Section: Introductionmentioning

confidence: 99%

Catalytic-Site-Mediated Chain-End Control in the Polymerization of rac-Lactide with Copper Iminopyrrolide Complexes

et al. 2018

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Reaction of copper(II) methoxide with N-R-2-iminopyrroles (LH) and pyridylmethanol (R′OH) provided the dinuclear complexes {LCu(μ-OR′)} 2 (R = naphtyl, CHPh 2 , 2,6-xylyl, 2,6-diisopropylphenyl (diip), or p-bromobenzyl). All complexes crystallized as dinuclear compounds with a square-pyramidal coordination geometry around copper and either imine or pyridine (for R = diip) in the apical position. The naphthyl-substituted complex was inactive in rac-lactide polymerization at room temperature in benzene. All other complexes showed good activity with apparent rate constants of k obs = 0.16(1)−1.89(8) h −1 at 2 mM catalyst concentration. All complexes showed a preference for slight isotactic monomer enchainment with P m = 0.60−0.68. Stereoerror analysis indicate that the chain-end determines stereocontrol. A dependance of stereocontrol on the steric bulk of the ligand, on the initial monomer concentration and on the symmetry of the catalytic site support that the chiral information on the chain-end is mediated via the catalytic site (catalytic-site-mediated chain-end control).

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Synthesis and structural studies of copper(II) complex supported by –ONNO– tetradentate ligand: Efficient catalyst for the ring-opening polymerization of lactide

Cited by 23 publications

References 38 publications

Designing of Poly(l-lactide)–Nicotine Conjugates: Mechanistic and Kinetic Studies and Thermal Release Behavior of Nicotine

Designing of Poly(l-lactide)–Nicotine Conjugates: Mechanistic and Kinetic Studies and Thermal Release Behavior of Nicotine

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

Catalytic-Site-Mediated Chain-End Control in the Polymerization of rac-Lactide with Copper Iminopyrrolide Complexes

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