It is used in large quantities as a raw material for the production of organic phosphorus compounds. It is a triangular pyramidal molecule and hydrolyzes violently. Phosphorus trichloride, PCl 3, is a colorless fuming liquid (mp -112 ☌ and bp 75.5 ☌). LiPF 6 and R 4NPF 6 can be used as supporting electrolytes for electrochemical measurements. The hexafluorophosphate ion, PF 6 -, as well as BF 4 - is often used as a counter anion for cationic transition metal complexes. It was the first compound with which the famous Berry's pseudorotation was discovered as an exchange mechanism for axial and equatorial fluorine atoms (refer to Section 6.1). These fluorines exchange positions so rapidly that they are indistinguishable by 19F NMR. It is a triangular bipyramidal molecule and should have two distinct kinds of fluorine atoms. Phosphorus pentafluoride, PF 5, is a colorless gas (mp -93.7 ☌ and bp -84.5 ☌). Because it is as electron-attracting as CO, it acts as a ligand forming metal complexes analogous to metal carbonyls. Phosphorus trifluoride, PF 3, is a colorless, odorless, and deadly poisonous gas (mp -151.5 ☌ and bp -101.8 ☌). It is useful as a raw material for the production of pure silicon, organic silicon compounds, and silicones. It is a regular tetrahedral molecule, and reacts violently with water forming silicic acid and hydrochloric acid. Tetrachlorosilane, SiCl 4, is a colorless liquid (mp -70 ☌ and bp 57.6 ☌). AgBF 4 and NOBF 4 are also useful for 1-electron oxidation of complexes. Since its coordination ability is very weak, it is used in the crystallization of cationic complexes of transition metals as a counter anion like ClO 4. Alkali metal salts, a silver salt and NOBF 4 as well as the free acid HBF 4 contain this anion. Tetrafluoroborate, BF 4 -, is a tetrahedral anion formed as an adduct of BF 3 with a base F. It is a starting compound for the preparation of diborane, B 2H 6. Diethylether adduct, (C 2H 5) 2O:BF 3, is a distillable liquid and is used as a common reagent. It exists in the gaseous phase as a triangular monomeric molecule, and forms Lewis base adducts with ammonia, amines, ethers, phosphines, etc. It is also used as a catalyst for cationic polymerization. It is widely used as an industrial catalyst for Friedel-Crafts type reactions. But, please be patient as posts will appear after they pass our moderation.\( \newcommand\) Typical chlorides and fluorides of main group elementsīoron trifluoride, BF 3, is a colorless gas (mp -127 ☌ and bp -100 ☌) that has an irritating odor and is poisonous. ![]() Depending on how many posts we receive, you could be waiting up to 24 hours for your post to appear. Questions will be queued for posting immediately after moderationģ. Answers to questions will be posted immediately after moderationĢ. Look for the original source of contentĥ. Posting on the MathsGee Science Technology
0 Comments
Leave a Reply. |