lewis酸碱理论（Lewis acid-base theory）.docVIP

lewis酸碱理论（Lewis acid-base theory） How does Lewis acid compare the acidity of BCl3, BF3, AlCl3 and SiF4? SiF4 no lack of electronic bar, should be the weakest ah?! The rest should be AlCl3 BCl3 BF3 ============================================= Definition of electronic acid-base The theory holds that..: Any recipient of foreign electron pairs (molecules, ions, or atoms) called Lewis acid (Lewis) is referred to as a receptor; Any molecule, ion, or group of atoms that gives an electron pair is called the Lewis base (Lewis, base), or donor. Or: Lewis acid (Lewis, acid) is an atom, molecule, or ion that acts as an electron docking receptor (Electron, pair, acceptor); The Lewis base (Lewis, base) refers to an atom, molecule, or ion that can be used as an electron donor (Electron, pair, donor); Acid base reaction is the reaction between electron acceptor and electron pair to form coordination covalent bond Classification of Lewis acids 1, the metal cations in coordination compounds, such as [Fe (H2O), 6]3+ and [Cu (NH3) Fe3+ in 4]2+ and Cu2+ ions 2, the central atoms of some molecules and ions, even though they satisfy the 8 electron structure, still expand their coordination layer to accommodate more electron pairs, such as SiF4, a Lewis acid that combines 2 F - electron pairs to form [SiF6]2 - 3, some of the molecules and ions in the center of the atom also meet the 8 electron structure, but the valence electron rearrangement allows for more electron pairs. Again, the CO2 can accept the lone electron pair in the O atom of the OH - ion 4, some closed shell molecules through the antibonding molecular orbital to accommodate foreign electronic. Acetone solution of iodine showed typical brown, because I2 molecular antibonding accept oxygen atoms in acetone lone electron pair formation of complexes (CH3) and 2COI2. (TCNE) four - vinyl pi * orbital can accept lone pair. Common Lewis acids: 1. positive ion, metal ion: sodium ion, alkyl cation, nitro cation 2. by electron molecule