3. Ligands and complex ions Flashcards
What is a complex ion?
Metal ion surrounded by coordinately bonded ligands
What is a coordinate bond/ dative covalent bond?
a covalent bond
both electrons in shared pair come from same atom
What is a ligand?
atom/ion/molecule that donates a pair of electrons to a central metal atom/ion
What is the coordinate number?
Number of coordinate bonds formed with central metal atom/ion
In most complex ions i need to know about coordinate number is ___
4 or 6
Examples of small ligands?
H2O
CN-
NH3
Examples of large ligands?
Cl-
When ligands are small how many can fit around the central metal atom/ion?
6
When ligands are large how many can fit around central metal atom/ion?
4
6 coordinate bonds mean what shape?
octahedral
4 coordinate bonds usually mean what shape?
tetrahedral
4 coordinate bonds sometimes mean what shape?
square planar
What are ligands with 1 lone pair available for bonding called?
monodentate
4 examples of monodentate ligands
H2O
NH3
Cl-
CN-
What are ligands with 2 lone pairs available for bonding called?
bidentate
How many coordinate bonds can Bidentate ligands form?
2
1 example of a bidentate ligand
NH2CH2CH2NH2
ethane-1,2-diamine sometimes abbreviated to ‘en’
What are ligands that form 2 or more coordinate bonds called
multidentate
What is cis platin?
complex of platinum II
with 2 chloride ions and 2 ammonia molecules
what shape is cis platin
square planar
what is cis platin used as?
an anti cancer drug
why is cis platin named CIS-platin and not TRANS-platin?
2 chloride ions next to each other so complex ion is cis.
if 2 chloride ions opposite complex ion is trans.
how does cisplatin work?
- 2 chloride ligands easy to displace.
2.cis platin looses them and bonds to 2 nitrogen atoms on DNA molecule inside cancerous cell
3.
how does cisplatin work?
- 2 chloride ligands easy to displace.
2.cis platin looses them and bonds to 2 nitrogen atoms on DNA molecule inside cancerous cell - acts as a block on DNA. cancerous cell cant reproduce. cell will die since it cant repair damage
4
what is the downside to cisplatin?
prevents normal cells reproducing
can suppress immune system
can cause damage to kidneys.
why is cis platin named CIS-platin and not TRANS-platin?
2 chloride ions next to each other = cis.
if 2 chloride ions opposite = trans.
how does cisplatin work?
3 things
- 2 chloride ligands easy to displace -> looses chloride ligands
- bonds to 2 nitrogen atoms on DNA molecule (inside cancerous cell)
- acts as a block on DNA -> cancerous cell cant reproduce. cell will die since it cant repair damage.
what is the downside to cisplatin?
3 points
prevents normal cells reproducing
can suppress immune system
can cause damage to kidneys.
