Ring-Opening Polymerization ofl-Lactide Efficiently Triggered by an Amido-Indole. X-ray Structure of a Complex betweenl-Lactide and the Hydrogen-Bonding Organocatalyst

2009 ◽  
Vol 131 (42) ◽  
pp. 15088-15089 ◽  
Author(s):  
Sylvain Koeller ◽  
Joji Kadota ◽  
Alain Deffieux ◽  
Frédéric Peruch ◽  
Stéphane Massip ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
X Ray

ChemInform Abstract: Hydrogen-Bonding Organocatalysts for Ring-Opening Polymerization

ChemInform ◽  
2014 ◽  
Vol 45 (25) ◽  
pp. no-no
Author(s):  
Coralie Thomas ◽  
Brigitte Bibal
Keyword(s):  
Hydrogen Bonding ◽  
Ring Opening ◽  
Ring Opening Polymerization

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

1995 ◽  
Vol 73 (11) ◽  
pp. 2069-2078 ◽  
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.

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

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.

Ring-opening polymerization of gold macrocycles and self-assembly of a coordination polymer through hydrogen-bonding

2003 ◽  
pp. 2228 ◽  
Author(s):  
Tara J. Burchell ◽  
Dana J. Eisler ◽  
Michael C. Jennings ◽  
Richard J. Puddephatt
Keyword(s):  
Hydrogen Bonding ◽  
Coordination Polymer ◽  
Self Assembly ◽  
Ring Opening ◽  
Ring Opening Polymerization

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

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
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, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 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.

Synthesis and X-ray Structures of New Titanium(IV) Aryloxides and Their Exploitation for the Ring Opening Polymerization of ε-Caprolactone

2006 ◽  
Vol 45 (5) ◽  
pp. 2282-2287 ◽  
Author(s):  
Matthew G. Davidson ◽  
Matthew D. Jones ◽  
Matthew D. Lunn ◽  
Mary F. Mahon
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
X Ray

scholarly journals 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

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.

Σύνθεση γραμμικών και αστεροειδών πολυμερών αποτελούμενα από συστάδες με υψηλή παράμετρο αλληλεπίδρασης Flory-Huggins χ

2020 ◽  
Author(s):  
Μαρία-Μαλβίνα Σταθουράκη
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
X Ray ◽  
X Ray Scattering ◽  
Exclusion Chromatography

Σκοπό της διατριβής αυτής αποτελεί η σύνθεση και η μελέτη της αυτοοργάνωσης γραμμικών και αστεροειδών συμπολυμερών με υψηλή παράμετρο αλληλεπιδρασης Flory-Huggins, χ. Τα πολυμερή αυτά, λόγω της μικρής αναμιξιμότητας που παρουσιάζουν τα συστατικά τους, έχουν την δυνατότητα σε μικρά μοριακά βάρη να μπορούν να σχηματίζουν πολύ μικρές και καλά καθορισμένες δομές κατά το μικροφασικό διαχωρισμό. Αρχικά, πραγματοποιήθηκε η σύνθεση των γραμμικών δισυσταδικών συμπολυμερών πολυ(2-βινυλοπυριδίνης)-b-πολυ(l-λακτιδίου) (P2VP-b-PLLA) και των τρισυσταδικών πολυ(l-λακτιδίου)-b-πολύ(διμεθυλοσιλοξάνη)-b-πολύ(l-λακτιδίου) (PLLA-b-PDMS-b-PLLA), καθώς και γραμμικών και αστεροειδών συμπολυμερών πολύ(στυρένιο)-b-πολυ(μονομεθακρυλική γλυκερόλη), PS-b-PGMA, (πολυστυρένιο)2(πολυ(μονομεθακρυλική γλυκερόλη)), (PS)2(PGMA), και (πολυστυρένιο)3(πολυ(μονομεθακρυλική γλυκερόλη)), (PS)3(PGMA), σε διάφορες αναλογίες μοριακών βαρών των συστατικών τους. Χρησιμοποιήθηκαν τεχνικές ζωντανού ανιοντικού πολυμερισμού για τη σύνθεση της P2VP, καθώς και για τη σύνθεση των αστεροειδών πολυμερών, ενώ η σύνθεση των PLLA πραγματοποιήθηκε με χρήση πολυμερισμού διάνοιξης δακτυλίου (Ring Opening Polymerization, ROP). Ο μοριακός χαρακτηρισμός των πολυμερών έγινε μέσω Χρωματογραφίας Αποκλεισμού Μεγεθών (Size Exclusion Chromatography, SEC) και Φασματοσκοπίας Πυρηνικού Μαγνητικού Συντονισμού Πρωτονίου (Nuclear Magnetic Resonance Spectroscopy, 1H-NMR). Τέλος, τίθενται τα αποτελέσματα που αφορούν τα γεωμετρικά χαρακτηριστικά (μέγεθος, μορφολογία) των περιοδικών νανοδομών που σχηματίζουν στο τήγμα τα συμπολυμερή, μέσω σκέδασης ακτίνων Χ σε μικρές γωνίες (Small-angle X-ray Scattering, SAXS).

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