What the heck is a "π" in inorganic chemistry and what is its charge?
Need to determine whether a chemical follows the 18-electron count. The metal is attached to "(π-c5h5)." What is this and what is its charge? And if anyone knows can you please tell me the charge of "(π-c6h6)" as well. I have no idea what those are. Searched google too. Found some π-things but no clear explanation of "π." Thanks.
More Questions From This User See All
Answers & Comments
Verified answer
really this is organometallic chemistry. The charge of PI-C5H5 is -1 while the charge of Pi-C6H6 is 0. These are bonds between the pi clouds of the C5H5 or C6H6 and the metal atom. Difficult to explain on one dimensional board here.
These are types of ligands attached to metals like ferrocene (C5H5-Fe-C5H5) and dibenzene chromium (C6H6-Cr-C6H6).
So charges in ferrocene would be Fe+2 each C5H5 -1 for -2 total. C6H6-Cr-C6H6 would be Cr 0 and each C6H6 0.
For further information of ligands, ferrocene dibenzene chromium, see wikipedia.
Just to clarify further: the five C atoms in the Cp rings of ferrocene (π-C5H5)2Fe are equidistant to the Fe and the rings spin at fantastically fast rates. Cp2Fe forms air-stable orange xtls; mp 166°C as I recall, dec ~400°C; sublimes even at RT. The same is true for the rings in dibenzene chromium (air sensitive black xtls). IUPAC does not approve of the π designation and should be replaced by η (hapto) If all the C atoms of the organic ligand are bound then no superscript is needed (η-C5H5)2Fe
(penthapto-cyclopentadienly)iron(II); (η-C6H6)2Cr. If only three or one C atom of the C5H5 is bound then this is indicated by superscripts: (η^3-C5H5)M (these are known) or the famous compound
(η-C5H5)Fe(CO)2((η^1-C5H5).
π denotes the type of bonding, it's not a particle. the π bond can be considered to be formed from atomic p-orbitals (as opposed to the more usually encountered σ bond formed from atomic s-orbitals).
C6H6 (benzene) is neutral.
C5H5- (cyclopentadieneyl) is negatively charged.