Investigation on cationic ring-opening polymerization of 1,5,7,11-tetraoxaspiro [5,5] undecane in the presence of low molecular weight tetraols

Polymer ◽  
2001 ◽  
Vol 42 (4) ◽  
pp. 1337-1344 ◽  
Author(s):  
Yan-Ming Guo ◽  
Ying-Fang Zou ◽  
Cai-Yuan Pan
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Low Molecular Weight ◽  
Cationic Ring Opening Polymerization

Diol glycidyl ether-bridged low molecular weight PEI as potential gene delivery vehicles

2015 ◽  
Vol 3 (13) ◽  
pp. 2660-2670 ◽  
Author(s):  
Qian Guo ◽  
Yan-Hong Liu ◽  
Miao-Miao Xun ◽  
Ji Zhang ◽  
Zheng Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gene Delivery ◽  
Ring Opening ◽  
Transfection Efficiency ◽  
Glycidyl Ether ◽  
Ring Opening Polymerization ◽  
Low Molecular Weight ◽  
Delivery Vehicles ◽  
Gene Delivery Vehicles

PEI 600-based polymers were synthesized via ring-opening polymerization and exhibited much better transfection efficiency and biocompatibility than PEI 25 kDa.

scholarly journals Pentamethylcyclopentadienyl Molybdenum(V) Complexes Derived from Iodoanilines: Synthesis, Structure, and ROP of ε-Caprolactone

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1554
Author(s):  
Tian Xing ◽  
Mark R. J. Elsegood ◽  
Sophie H. Dale ◽  
Carl Redshaw
Keyword(s):  
Molecular Weight ◽  
Comparative Studies ◽  
Ring Opening ◽  
Kinetic Studies ◽  
Ring Opening Polymerization ◽  
Molecular Structures ◽  
Low Molecular Weight ◽  
End Groups ◽  
Amine Complex ◽  
Reaction Stoichiometry

The reaction of [Mo(η-C5Me5)Cl4] with the ortho-, meta-, or para-iodo-functionalized anilines 2-IC6H4NH2, 3-IC6H4NH2, 4-IC6H4NH2 yields imido or amine products of the type [Mo(η-C5Me5)Cl2(IC6H4N)] (2-I, 1, 3-I, 3, 4-I, 5) or [Mo(η-C5Me5)Cl4(IC6H4NH2)] (3-I, 2, 4-I, 4), respectively, depending on the reaction stoichiometry/conditions; we were unable to isolate an amine complex of the 2-I derivative. The reaction of [Mo(η-C5Me5)Cl4] with one equivalent of 2-I,4-FC6H3NH2 in the presence of Et3N afforded [Mo(η-C5Me5)Cl2(2-I,4-FC6H3N)]·MeCN (6·MeCN), which, upon exposure to air, afforded the Mo(VI) imido complex [Mo(η-C5Me5)Cl3(2-I,4-FC6H3N)] (7). For comparative studies, the structure of the aniline (C6H5NH2)-derived complex [Mo(η-C5Me5)Cl2(2-C6H3N)] (8) has also been prepared. The molecular structures of 1–8 have been determined and reveal packing in the form of zig-zag chains or ladders. The complexes catalyze, in the presence of benzyl alcohol under N2, the ring-opening polymerization (ROP) of ε-caprolactone affording relatively low molecular weight products. The MALDI-ToF spectra indicate that a number of polymer series bearing a variety of end groups are formed. Conducting the ROPs as melts or under air results in the isolation of higher molecular weight products, again bearing a variety of end groups. Kinetic studies reveal the aniline-derived imido complex 8 performs best, whilst a meta-iodo substituent and a Mo(V) centre are also found to be beneficial. The structures of the side products 2-IC6H4NH3Cl and 3-IC6H4NH3Cl are also reported.

scholarly journals Fast and Convenient Synthesis of Amine-Terminated Polylactide as a Macroinitiator forω-Benzyloxycarbonyl-L-Lysine-N-Carboxyanhydrides

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mingjie Ju ◽  
Feirong Gong ◽  
Shujun Cheng ◽  
Yun Gao
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Low Molecular Weight ◽  
Amine Group ◽  
H Nmr ◽  
Convenient Synthesis ◽  
Ft Ir ◽  
Chain Lengths

Amine-terminated poly (L-lactide) (NH2-PLLA) with various chain lengths were successfully synthesized by sequential tert-butyl-N-(3-hydroxypropyl) carbamate initiated bulk ring-opening polymerization (ROP) of L-lactide (L-LA) in the presence of Stannous(II) 2-ethylhexanoate (Sn(Oct)2) and deprotection of theN-tert-butoxycarbonyl (Boc) group at the end of the polymer chain. The polymers obtained were characterized by FT-IR,1H NMR, and GPC method. NH2-PLLA thus prepared was used to initiate the polymerization of ω-benzyloxycarbonyl-L-lysine-N-carboxyanhydride (Lys (Z)-NCA), and the result confirmed the high nucleophilicity of the terminal amine group. This method was not only suitable for the preparation of low molecular weight NH2-PLLA, but also quite efficient in the synthesis of high molecular weight samples.

Structures and potential applications of multihydroxyl branched polyethers obtained by cationic ring-opening polymerization involving activated monomer mechanism

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Melania Bednarek
Keyword(s):  
Ring Opening ◽  
Star Polymers ◽  
Ring Opening Polymerization ◽  
Cyclic Ethers ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Potential Applications ◽  
Cationic Ring Opening Polymerization ◽  
Highly Strained ◽  
Thermodynamic Restrictions

AbstractThe synthesis and potential applications of functional, branched polyethers prepared by cationic ring-opening polymerization is reviewed, mainly on the base of the work from the author’s laboratory. Polymerization of cyclic monomers of ABx type, including highly strained 3- and 4-membered as well as weakly strained 5-membered cyclic ethers substituted with hydroxyl groups is discussed. Cationic polymerization of such monomers proceeds with participation of activated monomer mechanism which leads to the formation of branches. Hydroxy-substituted 4-membered cyclic ethers are highly strained; thus there are no thermodynamic restrictions for their polymerization, but these monomers are not easily available. Thus the possibility of using easily accessible 5-membered hydroxy-substituted cyclic ethers as monomers for cationic ring-opening polymerization was explored in spite of expected thermodynamic limitations due to low ring strain of those monomers. It was found that 5-membered hydroxysubstituted cyclic ethers undergo polymerization; however only low molecular weight products may be obtained from these monomers. It is shown in this review that such products may be useful and some examples of their applications in further synthesis e.g. in the preparation of star polymers and as surface modifying agents in the synthesis of organic/inorganic hybrid materials are described.

Catalytic Ring-Opening Polymerization of Renewable Macrolactones to High Molecular Weight Polyethylene-like Polymers

2011 ◽  
Vol 44 (11) ◽  
pp. 4301-4305 ◽  
Author(s):  
Inge van der Meulen ◽  
Erik Gubbels ◽  
Saskia Huijser ◽  
Rafaël Sablong ◽  
Cor E. Koning ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document