Question

Identify the first-row transition metal (M) that follows the 18-electron rule for each of the following compounds (show how you arrived at your answer): (a) [M(CO)2(PPh3)2] (c) [M(n5-CsHs)(CO)3]2 (assume single M-M bond) (b) [M(nt-C4H4)(CO)3]

Answer 1

The 18 electron rule is the method of counting of electron of the complex which involves the valence shell electrons of the metal atom plus the electrons which are donated by the ligand. The complexes which obeys the 18 electrons rule are considered as the stable complexes. See below hand written images for the explanation :

metal and ligands. f metal all valnce eut te ond the numbu duluovu donated te li he ch el ce w 'จ alo added

^i 0ん0 kule . Hence M = fe . Jhe- ele tuon, e, eon $1ue thenew M-M (metal-natal) bend, thu . one M +5+6+1 = 18

M1218 うMuu , M muut have 6 elutou m the valin ekull lation 2
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