[Chaste]

with respect to this complex : trans-Pt(NH₃)₂Cl₂ which 2 groups are trans to each other? My attempt at the question is Chloro and Ammine group are trans.

and my complementary question being: for cis-Pt(NH₃)₂Cl₂, which groups are cis to each other? My attempt at the question is Chloro and Chloro group are cis.

Someone please verify with me. thx.

[AWK]

http://en.wikipedia.org/wiki/Cis-platin

[Chaste]

so what about cis-PtCl₂(NH₃)(PPh₃)?

[AWK]

http://en.wikipedia.org/wiki/Cis-trans_isomerism

[Chaste]

http://en.wikipedia.org/wiki/Cis-trans_isomerism

sorry, I don't see how I can get my answer from this webpage. I have 3 substituents in cis-PtCl2(NH3)(PPh3)

[408]

you have two chlorides in a tetrahedral molecule, and two other ligands.  Each will be coming out of the metal centre on a common plane, say XY.  Are the chlorines next to eachother (cis) or opposing eachother (trans)?

[Chaste]

Is there cis or trans in a tetrahedral complex? anyway, i'm referring to square planer Pt complexes.

[AWK]

Look at preference of substutuents which is shown in wikipedia link. two substituent with highest preferences on the same side of square - cis , on the diagonal of square -trans, and it does not matter if they are different or the same.

[408]

Oh balls!  I am sorry!  I meant to say square planar.

[Chaste]

then to 408, my answer would be cis.