Isolobal relationships, CAR

Cluster chemistry
- Octahedral cluster
metalloboranes
Interstitial atoms in clusters

Isolobal principle
Metal-metal multiple bonds: quadruple bonds, quintuple bonds, sextuple bonds, delta bonds

Deltahedra to learn

Deltahedra: polyhedra whose faces are all equilateral triangles. Geomag toys can be very useful for visualising and understanding deltahedra. There's also a corresponding Jmol page with real examples of the deltahedra and their derivatives.

Number of vertices	CAR name	Wikipedia article	MathWorld article	Number of faces
n = 4	tetrahedron	Tetrahedron	Tetrahedron	4
n = 5	trigonal bipyramid	Trigonal bipyramid	Triangular Dipyramid	6
n = 6	octahedron	Octahedron	Octahedron	8
n = 7	pentagonal bipyramid	Pentagonal bipyramid	Pentagonal Dipyramid	10
n = 8	triangular dodecahedron	Snub disphenoid	Snub Disphenoid	12
n = 9	tricapped trigonal prism	Triaugmented triangular prism	Triaugmented Triangular Prism	14
n = 10	bicapped square antiprism	Gyroelongated square dipyramid	Gyroelongated Square Dipyramid	16
n = 11	octadecahedron	Octadecahedron	Deltahedron: not convex	18
n = 12	icosahedron	Icosahedron	Icosahedron	20