4 TRANSITION METALS Flashcards
what binds ligands to form complexes?
transition metals
what do ligands do?
act as lewis bases…donate e-. the donor atom is directly bonded to the metal
what is a monodentate ligand?
has one donor atom
what is a bidentate ligand?
has two donor atoms
what type of ligand is EDTA?
hexadentate
what are linkage isomers?
complexes that differ only by which atom in the ligand is the donor atom (NEEDS TO BE POLYDENTATE)
what are coordination isomers?
two complexes that differ only by which metal is in the cation/anion
what are ionization isomers?
complexes that differ only by the interchange of an anionic ligand and anionic counterion
what is the coordination number?
number of donor atoms bonded
what is the usual stereochemistry for coordination number 2?
linear
what is the usual stereochemistry for the coordination number 3?
usually trigonal planar
what is the usual stereochemistry for coordination number 4?
tetrahedral/square planar. for the square planar with two like ligands, cis/trans is possible
what is the usual stereochemistry for coordination number 5?
trigonal bipyramidal or square planar
what is the usual stereochemistry for coordination number of 6?
octahedral or distorted octahedral
what is the most common coordination number? when is stereochemistry not possible?
- if all donor atoms are the same or only one is different, no stereochemistry is possible
when is fac/mer isomerism possible?
when there are 3 like ligands
what are carbonyl complexes?
metal complex with carbon monoxide
what is the coordination number of the metal ion that bonds to the hemegroup? what is the metal ion
the coordination number of Fe2+ is 6
what is crystal field theory
model to explain colours and paramagnetism of transition metal complexes
what are the assumptions in the crystal field theory?
transition metal ion is free metal cation by itself.
ligands are point charges.
bonds between metal and ligand is electrostatic (ionic/no covalent character).
resulting electrostatic field = crystal field
is the repulsion in d-orbital ligands uniform?
NO
what are the factors affecting delta o? (energy difference between sets of orbitals in octahedral field)
oxidation state of the metal ion (greater oxidation state = greater delta o)(smaller cation = closer ligands = more repulsion). metal identity (larger metal = greater delta o). larger d orbitals = better metal/ligand. orbital overlap = more repulsion nature of the ligand.
what colour is absorbed?
the complementary colour to the one we see
what are the complimentary colour pairings?
R&G. O&B. Y&V.
what does it mean if black is the colour perceived?
all wavelengths of the visible spectrum were absorbed
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