[kriggy]

Im not sure if I understand this terms right.
Basicaly, kinetics is about the speed of reaction.
 So if we are talking about coordination compounds, I can say that d3 octaheral complexes will be stable because when the coordination number is changed (increased or lowered by 1 in transition state), the LFSE lowers so the compound would be less stable so its kineticaly inert.
 If I have high spin d4 copound, it will be kineticaly labile because when the coordination number changes to tetrahonal pyramidal or pentagonal bipyramidal, the transition state is more stable.


 Thermodynamics is about the energy of the lowest state of the system. Can I predict the thermodynamical stability of compound from its structure? Does it depend on the enviroment? For example, can I say that [M(NH₃)₆]ⁿ⁺ will be thermodynamicaly stable when in solution of amonia but not stable when in water because the water is in huge excess so there will be some substitution of ligands (even if it can be very slow)?

Do I understang those terms somehow correctly or am I missing some crutial points?
thanks

edit: and one more question:
If I have complex with one tetradentate chelating ligand (Tris(2-aminoethyl)amine for example) and 2 monodentate ligands ([M(tren)X₂]), why is that in substitution reaction, when the intermediate is trigonal bipyramidal there is only one isomer but when the intermediate is square pyramidal there are two isomers?