Page 179 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

C O O R D I N A T I O N C O M P O U N D S IR-9.2

6. Ph P PPh 3
3
Pt
O 3 O
C C
OC CO
Fe 1 2 Fe
OC CO
C C
O O
4
4
octacarbonyl-1k C,2k C-bis(triphenylphosphane-3kP)-triangulo-
diironplatinum(Fe—Fe)(2 Fe—Pt)

7. [Os 3 (CO) 12 (SiCl 3 ) 2 ]
O O O
C C C
CO CO CO
1 3 2
Cl Si Os Os Os SiCl 3
3
OC OC OC
C C C
O O O
4
4
4
dodecacarbonyl-1k C,2k C,3k C-bis(trichlorosilyl)-1kSi,2kSi-
1
2
3
3
triosmium(Os —Os )(Os —Os )
All three osmium atoms have four carbonyl ligands. T he two osmium atoms with
trichlorosilyl ligands are assigned central atom locants 1 a nd 2, as these l igands are the first
that are not evenly distributed. Symmetry in the structure means that the locants 1 a nd 2 c an
be assigned either way around.
Example:

8. Ph +
Ph P 2 P PPh 2
O C 1 2 C O 3 Cl
Rh Rh Rh
Cl O C
Ph P 2 P PPh 2

Ph
2
tricarbonyl-1kC,2kC,3kC-m-chlorido-1:2k Cl-chlorido-3kCl-bis{m 3 -
0
bis[(diphenylphosphanyl)methyl]-1kP:3kP -phenylphosphane-2kP}trirhodium(1þ)
1
or, using t he preferred IUPAC name for the phosphane ligand:
2
tricarbonyl-1kC,2kC,3kC-m-chlorido-1:2k Cl-chlorido-3kCl-
bis{m 3 -[phenylphosphanediyl-1kP-bis(methylene)]bis(diphenylphosphane)-
0
00
2kP :3kP }trirhodium(1þ)
Example 8 i llustrates how using d ifferent (equally systematic) names for ligands may
result in different additive names and different locant numberings.

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