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171.
172.
Starting from 2‐furylfulvene (1a) , 2‐thiophenylfulvene (1b) , and 1‐methyl‐2‐pyrrolylfulvene (1c), [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐furyl)ethanediyl] titanium dichloride (2a) , [1,2‐di(cyclopentadienyl)‐1,2‐di‐(2‐thiophenyl)ethanediyl] titanium dichloride (2b) , and [1,2‐di(cyclopentadienyl)‐1,2‐bis‐(1‐methyl‐2‐pyrrolyl)ethanediyl] titanium dichloride (2c) were synthesized. When titanocenes (2a–c) were tested against pig kidney carcinoma cells (LLC‐PK), inhibitory concentrations (50%) of 4.5 × 10?4 M , 2.9 × 10?4 M and 2.0 × 10?4 M respectively were observed. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
173.
This paper reports on the use of a multi-goal linear programming model to establish the tuition and fee policy at a major state university over a three-year period. The process of establishing tuition and fee charges is characterized by multiple and conflicting goals. Further complicating the process is the fact that multiple parties are involved in or impact on the decision process, including the various academic and administrative units of the university, the state legislature, parents and students. The charges are established based on the institution's anticipated operating costs and fiscal needs, state-level policies and requirements, projected enrolment patterns, charges at peer institutions, and the university's philosophy concerning differential charges between various student categories. The modelling process employed provides university administration with the maximum possible flexibility in stating and prioritizing university goals and objectives regarding the tuition and fee structure.  相似文献   
174.
Laurence Beaufort 《Tetrahedron》2005,61(38):9025-9030
Chelating diiminophosphorane and tripodal iminophosphorane copper and palladium complexes are found to efficiently catalyze the cyclopropanation of activated monosubstituted olefins with ethyl diazoacetate. Cycloolefins, and linear α-olefins are somewhat less reactive. The diastereoselectivities of the reactions are moderate and no major differences were seen when comparing the bidentate chelating ligand to the tripodal ligands.  相似文献   
175.
New routes to ladder‐type phenylene materials 1 and 2 are described. The oligomers 1 and 2 , which possess a “3π‐2spiro” architecture, have been synthesized by using extended diketone derivatives 3 and 10 as key intermediates. The physicochemical properties of the new blue‐light emitter 2 were studied in detail and compared with those of the less‐extended 1 . Owing to the recent development of fluorenone derivatives and their corresponding more conjugated analogues as potential electron‐transport materials in organic light‐emitting diodes (OLEDs) and as n‐type materials for photovoltaic applications, we also report herein the thermal, optical and electrochemical behavior of the key intermediates, diketones 3 and 10 . Finally, the application of dispiro 2 as a new light‐emitting material in OLEDs is reported.  相似文献   
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The electronic effects of X substituents in aromatic molecules XC6H5, XC6H4Me and XC6H4OMe are studied by measurements of the bonded OH frequencies of phenol-π-base complexes. A judicious choice of the experimental conditions (solvent, π-base concentration, phenol acidity, temperature) permits the following substituents to be studied: Me, Et, CH(Me)2, OMe, OEt, OC6H5, NHMe, N(Me)2, N(Et)2, NHC6H5, C6H5, CHCH2, CCH, CCMe, SMe, SC6H5, F, Cl, Br and I.Halogenated benzenes, benzotrichloride and benzotrifluoride were found to act solely as π-bases. Electronic effects are accurately measured by means of the linear combination ?1σ1 + ?RR. The ratio ?R/?1 shows that inductive and mesomeric effects are of the same importance. This ratio may be considered as an argument in favour of the symmetric configuration of the complex. Electronic effects are found to be additive in disubstituted benzenes.  相似文献   
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Energy levels and rotational constants are provided for all carbon dioxide infrared absorption transitions of significance for terrestrial atmospheric transmission. Constants have been recalculated using new FTS measurements in the 4.3 μm region at elevated temperature, new FTS measurements in the 15, 5, and 2 μm regions, precise laser measurements around 10 μm, and high resolution grating spectrometer measurements of isotopically enriched samples. Band centers, band strengths, and coriolis coupling constants are given for some 560 bands.  相似文献   
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