[Big-Daddy]

The (E,Z) naming system is encouraged for naming substituents around C=C double bonds but, when encountering other cases of geometric isomerism such as in cycloalkanes or in complex ions, I always find cis-trans naming being used instead. Why is E,Z-naming not the system used for these cases as well?

[JGK]

for probably the same reason we all ignore IUPAC nomenclature for other  when talking about most chemical structures. It OK for the small stuff but soon gets hideously complicated.

[Big-Daddy]

for probably the same reason we all ignore IUPAC nomenclature for other  when talking about most chemical structures. It OK for the small stuff but soon gets hideously complicated.

Complicated? You just follow the Cahn-Ingold-Prelog rules through to the end, where's the complication? And in any situation where it is possible to indicate the name with cis/trans it must be possible to do so with E,Z?

[Dan]

cis/trans can be ambiguous in the case of tri- or tetra-substituted alkenes because the naming is not strictly associated with priority rules - hence E/Z is preferred.

Ambiguity is also a problem for multiple substitution on aliphatic cyclic systems for the same reason. The more rigorous description  in these systems is assigning each centre R/S or r/s (the latter is for pseudoasymmetric centres).

Big-Daddy, it can get surprisingly complicated. For example, try to assign r/s to the pseudasymmetric centres of cis-cyclohexane-1,4-diol.

[Big-Daddy]

cis/trans can be ambiguous in the case of tri- or tetra-substituted alkenes because the naming is not strictly associated with priority rules - hence E/Z is preferred.

Ambiguity is also a problem for multiple substitution on aliphatic cyclic systems for the same reason. The more rigorous description  in these systems is assigning each centre R/S or r/s (the latter is for pseudoasymmetric centres).

Big-Daddy, it can get surprisingly complicated. For example, try to assign r/s to the pseudasymmetric centres of cis-cyclohexane-1,4-diol.

I'm not talking about R/S for now though. I was wondering why E/Z isn't the system commonly used for substituted cycloalkanes and complex ions, for instance. And if there would be any defect or problem that would arise from using E/Z instead of cis/trans for such cases.