CHEM 001C Lecture Notes - Lecture 9: Denticity, Square Planar Molecular Geometry, Covalent Bond
CHEM 001C Lecture 9: Coordination Chemistry
●Lewis Acids/Bases: Coordinate Covalent Bonds
○Example: 2NH3(aq) + [PtCl4]2- → [Pt(NH3)2(Cl)2] + 2Cl-
■[Pt(NH3)(Cl)2] = coordinate covalent bond
●CN = coordination number (number of bonds on metal)
○NOT the number of ligands bound (some are bidentate)
■Bidentate: two parts of the same ligand can bind to a metal
○CN #4: square planar geometry
○CN #6: octahedral geometry
●Naming Coordinate Covalent Complexes/ Complex Ions
○Neutral or positive complexes/ complex ions:
■Name ligands using common names listed in lecture
●If multiple ligands are present, list alphabetically
■Use prefixes to indicate number of ligands (di, tri, tetra, etc.)
●If ligand has a prefix, use alternate prefixes (bis, tris, tetrakis, etc.)
■Write the name of the metal ion using a Roman numeral to indicate the
charge
■Add the name of the negatively charged ion after the complex name
○Negative complexes/ complex ions:
■Same process as with neutral or positive complex ions
■Write the name of the metal ion using a Roman numeral to indicate the
charge, but add “ate” to the end of the metal name to indicate a negatively
charged complex ion
●Use ferrate, cuprate, aurate for Fe, Cu, Au
■Add the name of the positively charged counterion before the name of the
complex ion
Document Summary
Example : 2nh 3 (aq) + [ptcl 4 ] 2- [pt(nh 3 ) 2 (cl) 2 ] + 2cl - Cn = coordination number (number of bonds on metal) Not the number of ligands bound (some are bidentate) Bidentate : two parts of the same ligand can bind to a metal. Name ligands using common names listed in lecture. If multiple ligands are present, list alphabetically. Use prefixes to indicate number of ligands (di, tri, tetra, etc. ) If ligand has a prefix, use alternate prefixes (bis, tris, tetrakis, etc. ) Write the name of the metal ion using a roman numeral to indicate the charge. Add the name of the negatively charged ion after the complex name. Same process as with neutral or positive complex ions. Write the name of the metal ion using a roman numeral to indicate the charge, but add ate to the end of the metal name to indicate a negatively charged complex ion.
