Lewis acids and bases ionic bonding. Classically, the term "Lewis acid" is restricted to trigonal planar species with an empty p orbital, such as BR where R can be an organic substituent or a halide. For the purposes of discussion, even complex compounds such as EtAlCl and AlCl are treated as trigonal planar Lewis acids. Metal ions such as Na, Mg, and Ce, which are invariably complexed with additional ligands, are often sources of coordinatively unsaturated derivatives that form Lewis adducts upon reaction with a Lewis base[citation needed]. Other reactions might simply be referred to as "acid-catalyzed" reactions. Some compounds, such as HO, are
2012 Super League season results at Etihad Stadium as part of Magic Weekend<br> F. Galpharm Stadium renamed John Smith's Stadium as of 1 August 2012 <br> G. Game switched to Leigh Sports Village due to fixture clash with co-tenants Sale Sharks 2012 Super League season results This is a list of the 2012 Super League season results. Super League is the top-flight rugby league competition in the United Kingdom and France. The 2012 season started on 4 February and ends on 6 October with the 2012 Super League Grand Final at Old Trafford. The Magic Weekend was scheduled over the weekend of 26 and 27