Transition Metals - Iandalgleish.co.uk

ADVANCED HIGHER 8 TransMetsThe Spectrochemical SeriesThe ligand field splitting energy, ∆, depends on the power of theligand to squeeze the electrons in the d x 2 -y 2 and d z2 orbitals. Thespectrochemical series lists the ligands in order of increasedsplitting power:CN- > NH 3 > H 2 O! Compare the blue hexaaquachromium(III) and the magentahexaamminechromium(III) ions :Cr(H O) 3+2 6Cr(NH ) 3+3 6yellowgreenRRYMYMGCBGCBYellow light absorbedBlue light transmittedGreen light absorbedMagenta light transmitted! The hexaaquairon(II) ion contains unpaired electrons ; thehexacyanoiron(II) ion does not :Fe(H O) 2+2 6Fe(CN ) 4-6∆ is so great in the hexacyanoiron(II) ion that it is morefavourable for electrons to pair up and share orbitals thanjump up into the higher energy levels.