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Hi

the question asks to explain the trend you would see for M-M distance for complexes of the form M₂X₉^3- where x= halide for the 3 compounds Rh, Ru, Mo

so far this is what I've got from sources:
All 3 elements are in the same row and their radius increase as you go from left to right
Mo has triple bond
Rh would give a face sharing octahedral structure
Ru would a degree of Ru-Ru bonding

i don't understand how this explains the trends,,, help please!??