Exploring Factors That Determine Cis/Trans Structure and Tacticity in Polymers Prepared by Ring-Opening Metathesis Polymerizations with Initiators of the Type syn- and anti-Mo(NAr)(CHCMe2Ph)(OR)2. Observation of a Temperature-Dependent Cis/Trans Ratio

1995 ◽  
Vol 28 (17) ◽  
pp. 5933-5940 ◽  
Author(s):  
Richard R. Schrock ◽  
Jin-Kyu Lee ◽  
Richard O'Dell ◽  
John H. Oskam
1997 ◽  
Vol 130 (7) ◽  
pp. 951-954 ◽  
Author(s):  
Marcus Sigl ◽  
Schier ◽  
Hubert Schmidbaur

Author(s):  
T.E. Pratt ◽  
R.W. Vook

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.


2020 ◽  
Vol 11 (24) ◽  
pp. 3940-3950 ◽  
Author(s):  
Patrick Verkoyen ◽  
Holger Frey

Amino-functional polyethers have emerged as a new class of “smart”, i.e. pH- and thermoresponsive materials. This review article summarizes the synthesis and applications of these materials, obtained from ring-opening of suitable epoxide monomers.


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