Dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine–dichlorophenylborane

Dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine–dichlorophenylborane

In the crystal structure of the title compound, C(39)H(54)BCl(2)P, the phospho-rus atom is coordinated by a dichloro-phenyl-borane unit. The substituted biphenyl group and the two cyclo-hexyl groups at the phospho-rus atom are arranged in such a way to avoid steric crowding in the mol-ecule as far as possible.

An efficient transformation of primary halides into nitriles through palladium-catalyzed hydrogen transfer reaction.

Two-step one-pot transformation of primary halides into corresponding nitriles is successfully achieved. Nucleophilic substitution of primary halides with sodium azide and subsequent palladium-catalyzed hydrogen transfer proceeds smoothly in the presence of sterically bulky ligand dicyclohexyl(2',4',6'-triisopropylbiphenyl-2-yl)phosphine (XPhos) in acetone to produce nitriles in satisfactory to...

تعیین غلظت کریپتوفیکس 2، 2، 2 در رادیوداروی [18F]FDG

غلظت کریپتوفیکس 2،2،2 در محلول‌های [18F]FDG و استانداردهای کریپتوفیکس 2،2،2 به دو روش آشکارسازی (ترکیب کریپتوفیکس 2،2،2) با بخار ید و معرف یدوپلاتینات تعیین شد. در هر دو روش، تفاوت غلظت محلول‌های کریپتوفیکس، به صورت تفاوت در شدت رنگ لکه‌های آشکار شده بر روی TLC نمایان شد. حد تشخیص کریپتوفیکس با بخار ید و معرف یدوپلاتیتات به ترتیب ppm25 و ppm2 می‌باشد. هر دو روش را می‌توان برای پذیرش ...

Cover vol.2, no.2 October 2005

6 Concluding Remarks 5.2 Incorporate Database Categorization 5 Improving the Retrieval of Relevant Documents = 2:0m 2 2 2 2 2 2 2 2 2 2 2 = 2:0m 2 2 2 2 2 2 2 2 2 2 2

In this paper, we proposed a new, highly scalable method to solve the database selection problem when the number of local databases in a metasearch engine is very large. For single-term queries, this method guarantees all desired documents to be retrieved. Experiments were conducted to show that this method is very eeective for typical short Internet queries. We also illustrated that the our da...