A tetranuclear Sn(IV) 4-thiazolecarboxylate complex: synthesis, structure and catalytic behavior in the bulk ring-opening polymerization of glycolide

AbstractThe reaction of 4-thiazolecarboxylic acid (Htzc) and dimethyltin(IV) dichloride with NaOH in mixed MeOH-H2O solvent led to the formation of a new Sn(IV) complex (Me2Sn)4(μ3-O)2(tzc)4 (1). Its structure has been characterized by elemental analysis, IR spectroscopy and single crystal and powder X-ray diffraction. Single-crystal X-ray diffraction revealed that complex 1 crystallizes in the monoclinic P21/c space group with Z = 2 and has a tetranuclear structure with crystallographically imposed centrosymmetry. The as-synthesized complex 1 was found to be active toward the bulk solvent-free polymerization of glycolide, producing poly(glycolic acid) with a number-average molecular weight up to 55.5 kDa.

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The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

Canadian Journal of Chemistry ◽

10.1139/v95-255 ◽

1995 ◽

Vol 73 (11) ◽

pp. 2069-2078 ◽

Cited By ~ 12

Author(s):

Timothy J. Peckham ◽

Daniel A. Foucher ◽

Alan J. Lough ◽

Ian Manners

Keyword(s):

Molecular Weight ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Monoclinic Space Group ◽

Organometallic Polymers ◽

X Ray Diffraction ◽

X Ray ◽

Cyclopentadienyl Ligands ◽

Sterically Demanding ◽

High Molecular Weight Poly

The silicon-bridged [1]ferrocenophane Fe(η-C5H3SiMe3)2(SiMe2) (5) was synthesized via the reaction of Li2[Fe(η-C5H3SiMe3)2]•tmeda (tmeda = tetramethylethylenediamine) with Me2SiCl2 in hexanes. The disilane-bridged [2]ferrocenophane Fe(η-C5H3SiMe3)2(Si2Me4) (7) was prepared using a similar route from the disilane ClMe2SiSiMe2Cl. Despite the presence of sterically demanding SiMe3 substituents on the cyclopentadienyl rings, compound 5 was found to undergo thermal ring-opening polymerization at 170 °C to produce very soluble, high molecular weight poly(ferrocenylsilane) 6 with Mw = 1.4 × 105, Mn = 8.4 × 104. However, the [2]ferrocenophane 7 was found to be resistant to thermal ring-opening polymerization even at 350 °C and decomposed above 380 °C. A single-crystal X-ray diffraction study of 7 revealed that the steric interactions between the bulky SiMe3 groups are relieved by a significant twisting of the disilane bridge with respect to the plane defined by the centroids of the cyclopentadienyl ligands and the metal atom. The angle between the planes of the cyclopentadienyl rings in 7 was found to be 5.4(6)°, slightly greater than that in the non-silylated analogue Fe(η-C5H4)2(Si2Me4) (4a) (4.19(2)°), and dramatically less than the corresponding tilt angle of the strained, polymerizable, silicon-bridged [1]ferrocenophane Fe(η-C5H4)2(SiMe2) (1) (20.8(5)°). The length of the Si—Si bond in 7 (2.342(3) Å) was found to be close to the sum of the covalent radii (2.34 Å). Crystals of 7 are monoclinic, space group C2/c, with a = 23.689(3) Å, b = 11.174(1) Å, c = 31.027(3) Å, β = 109.16(1)°, V = 7758(2) Å3, and Z = 12. Keywords: ring-opening polymerization, ferrocenophane, organometallic polymers.

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Polymers of ε-Caprolactone Using New Copper(II) and Zinc(II) Complexes as Initiators: Synthesis, Characterization and X-Ray Crystal Structures

Polymers ◽

10.3390/polym10111239 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1239 ◽

Cited By ~ 5

Author(s):

Andrés Posada ◽

Mario Macías ◽

Santiago Movilla ◽

Gian Miscione ◽

León Pérez ◽

...

Keyword(s):

Single Crystal ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Nmr Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Molecular Weights ◽

Full Characterization ◽

Solvent Free Conditions

Five of six new Zn(II) and Cu(II) complexes were active in the ring-opening polymerization (ROP) of ε-caprolactone (CL) under solvent-free conditions, producing polycaprolactones (PCLs) of high crystallinity with molecular weights between 22,900 and 38,700 g mol−1 and decomposition temperatures above 260 °C. 1H NMR analysis demonstrated that the PCLs obtained were mainly linear, having hydroxymethylene groups at the chain ends. The results obtained indicated a significant improvement in terms of the ratio of monomer:initiator compared to related Cu(II) and Zn(II) complexes. In addition, the structures of the complexes 1 and 4 were determined by single-crystal X-ray diffraction. The synthesis and full characterization of all complexes are described in this paper.

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Synthesis, Characterization and Optical Properties of PLA / P3HT Blends Thin Films

NeuroQuantology ◽

10.14704/nq.2021.19.5.nq21057 ◽

2021 ◽

Vol 19 (5) ◽

pp. 132-138

Author(s):

Maan Abd-Alameer Salih ◽

Q.S. Kareem ◽

Mohammed Hadi Shinen

Keyword(s):

Thin Films ◽

Optical Properties ◽

Spin Coating ◽

Ring Opening ◽

Energy Gap ◽

Ring Opening Polymerization ◽

X Ray Diffraction ◽

X Ray ◽

Conductivity Increase ◽

Ft Ir

In this exploration Poly lactic corrosive (PLA) was orchestrated the ring-opening polymerization Poly lactic corrosive (PLA) blended with poly(3-hexylthiophene) (P3HT) which prepared by solution. Blends thin films Synthesis by spin coating technique and using Tetrahydrofuran (THF) as solvent. PLA powder was 'characterized by' 'X-ray' 'diffraction', '(FT-IR)'. pure Optical properties (PLA), (PLA)/P3HT blends thin films with different percentage of P3HT (0, 1, 2, and 3) wt% were investigated using UV-VS spectroscopy The results showed that the absorption, absorption coefficient, extinction coefficient and conductivity increase with increasing the rate of deformation P3HT, The energy gap decreases with increasing deformation.

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Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

Canadian Journal of Chemistry ◽

10.1139/v02-129 ◽

2002 ◽

Vol 80 (11) ◽

pp. 1469-1480 ◽

Cited By ~ 6

Author(s):

Karena Thieme ◽

Sara C Bourke ◽

Juan Zheng ◽

Mark J MacLachlan ◽

Fojan Zamanian ◽

...

Keyword(s):

Mass Spectrometry ◽

Differential Scanning Calorimetry ◽

Thermogravimetric Analysis ◽

Ring Opening ◽

Ring Opening Polymerization ◽

The Novel ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UVvis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 69 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

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Hydrogels formed from Fmoc amino acids

CrystEngComm ◽

10.1039/c5ce00801h ◽

2015 ◽

Vol 17 (42) ◽

pp. 8047-8057 ◽

Cited By ~ 53

Author(s):

Emily R. Draper ◽

Kyle L. Morris ◽

Marc A. Little ◽

Jaclyn Raeburn ◽

Catherine Colquhoun ◽

...

Keyword(s):

Amino Acids ◽

Molecular Weight ◽

Single Crystal ◽

Crystal Structures ◽

Diffraction Data ◽

Low Molecular Weight ◽

X Ray Diffraction ◽

X Ray ◽

Single Crystal Structures

A number of Fmoc amino acids can be effective low molecular weight hydrogelators; we compare single crystal structures to fibre X-ray diffraction data.

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End-Group Evaluation of HEMA Initiated Poly(ε-caprolactone) Macromonomers via Enzymatic Ring-Opening Polymerization

International Journal of Polymer Science ◽

10.1155/2015/458756 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

N. Ugur Kaya ◽

Y. Avcibasi Guvenilir

Keyword(s):

Molecular Weight ◽

Ring Opening ◽

Average Molecular Weight ◽

Gel Permeation Chromatography ◽

Ring Opening Polymerization ◽

Enzyme Concentration ◽

Polymer Chains ◽

Side Reactions ◽

Initiator Concentration ◽

Lower Temperature

Poly(ε-caprolactone) (PCL) macromonomers comprising acrylate end-functionality were synthesized via enzymatic ring-opening polymerization (eROP) by utilizing commercially availableCandida antarcticaLipase B (CALB), Novozyme-435. 2-Hydroxyethyl methacrylate (HEMA) was purposed to be the nucleophilic initiator in eROP. The side reactions generated due to the cleavage of ester bonds in HEMA and the growing polymer chains were investigated through altering polymerization period, initiator concentration, temperature, and enzyme concentration.1H NMR evaluations showed that minimum quantities of side reactions were in lower temperatures, initiator concentration, enzyme concentration, and lower monomer conversions. Gel permeation chromatography (GPC) results revealed that lower polydispersity along with number-average molecular weight of end-functionalized PCL macromonomers was obtained depending on higher initiator/monomer ratios, lower temperature (60°C), enzyme concentration (100 mg), and/or polymerization time (2 h). Furthermore, 0.1 HEMA/ε-caprolactone (CL) ratio had higher molecular weight than 0.5 HEMA/CL ratio, while keeping a close value of methacrylate transfer, total methacrylate end-groups, and lower polyester transfer.

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Yttrium and Lithium Keto-β-Diketiminate Complexes [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2Li(THF)2 and {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n. Synthesis, Molecular Structures, and Catalytic Activity in ε-Caprolactone Polymerization

Russian Journal of Coordination Chemistry ◽

10.1134/s107032842102007x ◽

2021 ◽

Vol 47 (2) ◽

pp. 144-154

Author(s):

G. G. Skvortsov ◽

A. V. Cherkasov ◽

D. L. Vorozhtsov ◽

E. S. Shchegravina ◽

A. A. Trifonov

Keyword(s):

Catalytic Activity ◽

Diffraction Analysis ◽

Exchange Reaction ◽

Ring Opening ◽

Crystalline State ◽

Ring Opening Polymerization ◽

Molecular Structures ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray

Abstract The reaction of lithium β-diketiminate [{2,6-Me2C6H3N=CMe}2CH]Li with benzophenone in toluene at 25°C affords the coordination complex [{2,6-Me2C6H3N=CMe}2CH]Li(Ph2C=O) (I). New keto-β-diketimine {2,6-Me2C6H3N=C(Me)}2CHC(tert-Bu)=O (II) is synthesized by the reaction of tert-Bu(C=O)Cl with [{2,6-Me2C6H3N=CMe}2CH]Li. The metallation of keto-β-diketimine II with n-butyllithium in THF at 0°C gives lithium keto-β-diketiminate {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n (III). The exchange reaction of YCl3 with compound III (molar ratio 1 : 2, THF) affords the yttrium bis(keto-diketiminate) complex [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2L-(THF)2 (IV). The molecular structures of complexes I, III, and IV are determined by X-ray diffraction analysis (CIF files CCDC nos. 2001131 (I), 2001132 (III), and 2001133 (IV)). Complex IV in the crystalline state exists as an ate complex with one LiCl molecule. Complexes I, III, and IV are catalysts of ring-opening polymerization of ε-caprolactone in toluene at 25°С.

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Thiophene ring-opening reactions IV. Facile generation of novel ethyl 4-hydroxy-6-thioxonicotinate─1,3,4- thiadiazoline hybrids

Letters in Organic Chemistry ◽

10.2174/1570178618666211110141423 ◽

2021 ◽

Vol 18 ◽

Author(s):

Mohammed M. Abadleh ◽

Ahmad H. Abdullah ◽

Jalal A. Zahra ◽

Salim S. Sabri ◽

Firas F. Awwadi ◽

...

Keyword(s):

Single Crystal ◽

Spectral Data ◽

1H Nmr ◽

13C Nmr ◽

Ring Opening ◽

Thiophene Ring ◽

X Ray Diffraction ◽

X Ray ◽

Mild Conditions ◽

Ring Opening Reactions

: A set of triethylammonium 4-oxo-6-pyridinethiolate–1,3,4-thiadiazoline hybrids (3a-e) were prepared via the reaction of ethyl 2-chloro-6-cyclopropyl-3- nitro-4-oxothieno[2,3-b]pyridine- 5-carboxylate (2) with the appropriate thiobenzoyl- hydrazide (1a-e) in acetonitrile and triethylamine. These hybrids were readily converted, under neutral mild conditions, into the corresponding 4-hydroxy-6-thioxopyridine –thiadiazoline hybrids (5a-e). The structures of the latter set are supported by HRMS, 1H NMR and 13C NMR spectral data and further confirmed by single-crystal X-ray diffraction studies. Alkylation of these hybrids in the presence of triethylamine occurred exclusively at the 6-thioxosulfur, yielding the respective 6-sulfanyl derivatives (6a-c).

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Grafting Polymerization of D,L-Lactide on the Surface of Halloysite Nanotubes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.1742 ◽

2013 ◽

Vol 275-277 ◽

pp. 1742-1745 ◽

Cited By ~ 1

Author(s):

Jing Jing Li ◽

Bing Hong Luo ◽

Jin Xi Zhang ◽

Ru Qiu Huo ◽

Chang Ren Zhou

Keyword(s):

Ring Opening ◽

Halloysite Nanotubes ◽

Ring Opening Polymerization ◽

Gravimetric Analysis ◽

Structure And Properties ◽

Thermal Gravimetric ◽

X Ray Diffraction ◽

Potential Measurement ◽

X Ray ◽

Before And After

Halloysite nanotubes (HNTs) surface-grafting poly(D,L-lactide) (g-HNTs) were synthesized by bulk ring-opening polymerization of D,L-lactide using stannous octoate as catalyst and HNTs as co-initiator. Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and zeta potential measurement were employed to elucidate the structure and properties of HNTs before and after grafting with D,L-lactide. FTIR spectrum certified the existence of poly(D,L-lactide) chains on the surface of g-HNTs. The amount of surface-grafted poly(D,L-lactide) measured by TGA was 4.6% in weight. The grafted poly(D,L-lactide) chains on the surfaces of HNTs can relieve the clustering effect of HNTs to some extents.

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