9.18 h ow many possible isomers are there of an octahedral complex having the formula m(abc)(nh3)(h2o)br, where abc is the tridentate ligand h2nic2h4iphic2h4iash2? how many of these consist of pairs of enantiomers? sketch all isomers, showing clearly any pairs of enantiomers. the tridentate ligand may be abbreviated as n—p—as for simplicity.