Search results for "Monomer"
showing 10 items of 857 documents
Kinetics of Anionic Living Copolymerization of Isoprene and Styrene Using in Situ NIR Spectroscopy: Temperature Effects on Monomer Sequence and Morph…
2019
The living anionic copolymerization of isoprene (I) and styrene (S) can afford a variety of different polymer microstructures that strongly depend on experimental parameters such as solvent, counte...
NMR Spectroscopic Characterization and DFT Calculations of Zirconium(IV)-3,3′-Br2–BINOLate and Related Complexes Used in an Enantioselective Friedel–…
2012
Experimental and theoretical studies on the structure of several complexes based on (R)-3,3'-Br-2-BINOL ligand and group (IV) metals used as catalysts in an enantioselective Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated ketones have been carried out. NMR spectroscopic studies of these catalysts have been performed, which suggested that at room temperature the catalysts would form a monomeric structure in the case of Ti-IV and a dimeric structure in the cases of Zr-IV and Hf-IV. Density functional theory (DFT) calculations clearly corroborate the conclusions of these experimental spectroscopic studies. The dimeric structure with a doubly bridged motif [Zr-2(IV)(mu-(R)-3,3'…
2021
The reaction of :AlAriPr8 (AriPr8 = C6H-2,6-(C6H2-2,4,6-iPr3)2-3,5-iPr2) with ArMe6N3 (ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) in hexanes at ambient temperature gave the aluminum imide AriPr8AlNArMe6 (1). Its crystal structure displayed short Al-N distances of 1.625(4) and 1.628(3) A with linear (C-Al-N-C = 180°) or almost linear (C-Al-N = 172.4(2)°; Al-N-C = 172.5(3)°) geometries. DFT calculations confirm linear geometry with an Al-N distance of 1.635 A. According to energy decomposition analysis, the Al-N bond has three orbital components totaling -1350 kJ mol-1 and instantaneous interaction energy of -551 kJ mol-1 with respect to :AlAriPr8 and ArMe6N:. Dispersion accounts for -89 kJ mol-1, w…
Complexes of organometallic compounds
1974
Abstract Novel complexes RClSntrid, where R is Me, Ph, n-Oct, and trid 2− are dianions of tridentate “planar” ligands with ONO and SNO donor atoms, were synthesized and investigated in the solid state by infrared and Mossbauer spectroscopy. Possible configurations are discussed; polymeric trigonal bipyramidal structures seem to occur, although five-coordinated monomers as well as octahedral dimers (via oxygen or sulfur bridges) are not excluded.
Complexes of Tin(IV) with Tridentate Ligands M�SSBAUER, Infrared, and Solution Phase Studies
1974
The configuration in the solid state and in solution phase of complexes of SuIV wit,li tridentate “planar” ligands, Sn(trid)2 and HNEt3Cl3 Sntrid, have been investigated by infrared and MOSSBAUER spectroscopy, as well as by osmometry, conductivity, and electronic and PMR spectroscopy. The presence of monomeric Sn(trid)2 and ionic [HNEt] [Cl3Sn trid−] species has been inferred. Octahedral type configurations are advanced for both classes of compounds. Komplexe des Zinn (IV) mit dreizahigen Liganden. Mossbauer- und IR-Spektren sowie Untersuchungen von Losungen Die Struktur von SnIV-Komplexen mit dreizahnigen “planaren” Liganden, Sn(trid)2 und HNEt3Cl2Sntrid, wurde in fester Phase und in Losun…
Anionic Polymerization of Terpene Monomers: New Options for Bio-Based Thermoplastic Elastomers
2021
Dimeric Hydrido Complexes of Rare-Earth Metals Containing a Linked Amido−Cyclopentadienyl Ligand: Synthesis, Characterization, and Monomer−Dimer Equ…
2000
Dimeric hydrido complexes of lutetium, ytterbium, and yttrium containing a linked amido−cyclopentadienyl ligand, [Ln(η5:η1-C5Me4SiMe2NCMe2R)(L)(μ-H)]2 (Ln = Lu, Yb, Y; R = Me, Et; L = THF, PMe3), w...
Toward Near-Infrared Emission in Pt(II)-Cyclometallated Compounds: From Excimers’ Formation to Aggregation-Induced Emission
2023
Two series of Pt(II)-cyclometallated compounds containing N^C^N tridentate and alkynyl-chromophore ligands have been synthesized and structurally characterized. The N^C^N ligands differ on the presence of R1 = H or F in the central aromatic ring, while six different chromophores have been introduced to the alkynyl moiety. Single-crystal X-ray structures for some of the compounds reveal the presence of weak intermolecular contacts responsible for the formation of some dimers or aggregates. The photophysical characterization shows the presence of two emission bands in solution assigned to the 3π–π* transition from the N^C^N ligands mixed with 3MLCT/3ILCT transitions (higher energy band) in de…
Cyclophosphazenes as versatile substrates in polymer chemistry
2004
In this article we present the synthesis of new cyclophosphazenes and their use as chain extenders, polymers compatibilizers, and monomers.
Ester Functional Epoxide Monomers for Random and Gradient Poly(ethylene glycol) Polyelectrolytes with Multiple Carboxylic Acid Moieties
2020
The tailormade ester functional epoxides, methyl 4,5-epoxypentenoate (MEP) and tbutyl 4,5-epoxypentenoate (tBEP), were synthesized in good overall yields (60–65%) in short reaction sequences. Both ...