What are the different kinds of f orbitals?

2 Answers
Apr 1, 2018

ff orbitals are very complex and difficult to describe with words.

Explanation:

So there is only one kind of ff orbitals and that is the ff orbital. I suppose you mean the different shapes of the ff orbitals.

So the ff orbitals have 7 different shapes (since n=4n=4 and l=3l=3 resulting in: -3, -2, -1, 0, 1, 2, 33,2,1,0,1,2,3) These structures can be seen in this picture:

https://fc.deltasd.bc.ca/~mannandale/oldchemsite/chemistry11/atomictheory/forbitals.htm

With the different dimensions. Hope it helps.

Apr 2, 2018

They are quite complicated, and can often do combinations of sigmaσ, piπ, deltaδ, and even phiϕ bonding.

For an introduction into these kinds of bonds:

Inorganic Chemistry, Miessler et al.

sigmaσ bonds are in every chemical bond. piπ bonds start showing up in double and triple bonds (e.g. "O"_2O2, "N"_2N2, etc), deltaδ bonds start showing up in quadruple bonds (see link), and phiϕ bonds aren't seen until a sextuple bond is made (e.g. in "Mo"_2Mo2 or "W"_2W2).


The 4f4f orbitals can be separated into three types (here, we use the convention that outer atoms point their yy axes inwards and zz axes upwards):

1)1) Two lobes - sigmaσ bonding only (m_l = 0ml=0)

  • The f_(z^3)fz3 (m_l = 0ml=0) is the only one that only sigmaσ bonds. It can bond head-on along the zz axis.

2)2) Six lobes - sigmaσ and piπ bonding, OR phiϕ bonding only (m_l = -3, +3, -1, +1ml=3,+3,1,+1)

  • The f_(y(3x^2 - y^2))fy(3x2y2) (m_l = -3ml=3) can sigmaσ bond along the xx axes (for example, with a p_ypy orbital) AND piπ bond along the yy axes (for example, with a p_xpx orbital, or a d_(xy)dxy orbital).

It can alternatively form a phiϕ bond (a six-lobed side-on overlap) along the xyxy plane (with another f_(y(3x^2 - y^2))fy(3x2y2) orbital in a bimetallic complex).

  • The f_(x(x^2 - 3y^2))fx(x23y2) (m_l = +3ml=+3) can sigmaσ bond along the yy axes (for example, with a p_ypy orbital) AND piπ bond along the xx axes (for example, with a p_xpx orbital, or a d_(xy)dxy orbital).

It can alternatively form a phiϕ bond (a six-lobed side-on overlap) along the xyxy plane (with another f_(x(x^2 - 3y^2))fx(x23y2) orbital in a bimetallic complex).

  • The f_(yz^2)fyz2 (m_l = -1ml=1) can form decent sigmaσ bonds along the yy axes, AND/OR piπ bonds along the yy AND zz axes.

It can alternatively form a phiϕ bond (a six-lobed side-on overlap) along the yzyz plane (with another f_(yz^2)fyz2 orbital in a bimetallic complex).

  • The f_(xz^2)fxz2 (m_l = +1ml=+1) can form decent sigmaσ bonds along the xx axes, AND/OR piπ bonds along the xx AND zz axes.

It can alternatively form a phiϕ bond (a six-lobed side-on overlap) along the xzxz plane (with another f_(xz^2)fxz2 orbital in a bimetallic complex).

3)3) Eight lobes - piπ bonding OR deltaδ bonding (m_l = -2, +2ml=2,+2)

  • The f_(z(x^2 - y^2))fz(x2y2) (m_l = -2ml=2) is for piπ bonding along ANY of the axes, x,yx,y, or zz. The lobes lie above and below each of the axes, but also along them.

It can alternatively form a deltaδ bond with another f_(z(x^2 - y^2))fz(x2y2) orbital in a bimetallic complex.

  • The f_(xyz)fxyz (m_l = +2ml=+2) is for deltaδ bonding along ANY of the planes (xz, yz, xyxz,yz,xy) (for example, with d_(xy)dxy, d_(xz)dxz, or d_(yz)dyz orbitals).

It can alternatively form a piπ bond with another f_(xyz)fxyz orbital in a bimetallic complex.