does "valuable" have a specific chemical meaning, or does this just mean that it's costly to produce or extract from natural sources and therefore "valuable" in a monetary sense. Not really critical to the meaning of the article, I'm just curious. Thx. Zero sharp 19:32, 5 January 2007 (UTC)
"Valuable" here means that BF3 is a USEFUL Lewis acid. It is used in myriad applications, from catalyzing aldol reactions to removal of a variety of protecting groups. This is a common term in organic chemistry, though as you point out it can be misleading. Shultzc (talk) 03:13, 25 March 2008 (UTC)
This is alluded to in the article at present, but is presented as an alternative explanation. It seems, though, that the above is a better explanation, compatible with calculated partial charges (B: +2.43, F: −0.81) which indicate BF3 is predominantly an ionic molecule. The fact that BF3 does not condense to an ionic solid is explained by "size limitations on the maximum coordination number" that boron can achieve. If BF3 adopted the AlF3 structure (ionic solid), boron would be octahedrally coordinated by six fluorides.
I was just using the terminology in the paper cited above. I can send you a copy if you like. I think your definition of π back bonding sounds like the most usual usage. Maybe F→B π donation is sometimes termed back bonding because it is in the opposite direction to the usual B-F bond polarity, with the much more electronegative fluorine drawing electron density away from boron.Ben (talk) 15:03, 10 February 2010 (UTC)
i find it very... irritating that in the equation boric acids formula is in parenthesis. either remove parenthesis or write as H3BO3
Steve Z: Previously listed anhydrous density of 2.167 g/cm3 was misleading. For liquid anydrous BF3, Carl Yaws' Chemical Properties Handbook liquid density curve ranges from 0.549 g/cm3 at critical temperature (-12.3 C) to 1.678 g/cm3 at -127 C, with 1.572 g/cm3 at atmospheric boiling point. Anhydrous BF3 can't be liquefied at 25 C, new density is ideal-gas density at 25 C and 100 kPa. —Preceding unsigned comment added by 216.203.59.252 (talk) 21:28, 16 April 2010 (UTC)