complex ions Flashcards
what is a complex ion
a central metal ion coordinately bonded to ligands
what is a coordinate bond
a covalent bond in which both electrons in the shared pair came from the same atom
what is a ligand
an atom, ion or molecule which donates a pair of electrons to a central metal ion
what is a coordination number
the number of coordinate bonds that are formed with the central metal ion
when ligands are small, how many can usually fit around a central metal ion
6
what are examples of smaller ligands
H2O, CN, NH3
what shape occurs when there are 6 coordinate bonds
octahedral
what are the bond angles in a octahedron
90
what shape does 4 coordinate bonds USUALLY mean
tetrahedral
what are the bond angles in a tetrahedral shape
109.5
which complexes with 4 coordination bonds dont form a tetrahedral shape
nickel and platin complexes
what shape do these form instead
square planar
what are the bond angles in a square planar shape
90
what is a monodentate ligand
ligands that have one lone pair available for coordinate bonding
what is a bidentate ligand
ligands that have two lone pairs available for coordinate bonding, each can form 2 coordinate bonds
what is a multidentate ligand
ligands that form two or more coordinate bonds
what is an optical isomer
a non superimposable mirror image
when does optical isomerism occur in complex ions
in octahedral complexes when 3 bidentate ligands are bonded to the central metal ion
what is cis-trans isomerism
a special type of E/Z isomerism when there are only two different groups involved
which compounds can show cis-trans isomerism
square planar and octahedral
what is a cis isomer
have the same groups on the same side
what is a trans isomer
have the same groups on opposite sides
