Transcript Document

Delta bonds: (dxy ± dxy) or (dx2-y2 ± dx2-y2)
(dxy + dxy) or (dx2-y2 + dx2-y2)
dg
Delta bonds: (dxy ± dxy) or (dx2-y2 ± dx2-y2)
(dxy - dxy) or (dx2-y2 - dx2-y2)
d*u
(dxy + dxy) or (dx2-y2 + dx2-y2)
dg
Bonding scheme for dimers of
transition metal dications, M2+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
d
d
pu (xz, yz)
sg (z2)
M2+
M24+
M2+
Example: dimerization of Cr2+
to form Cr24+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
pu (xz, yz)
d4
sg (z2)
Cr2+
Cr24+
d4
Cr2+
Example: dimerization of Cr2+
to form Cr24+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
pu (xz, yz)
d4
sg (z2)
Cr2+
Cr24+
d4
Cr2+
Bond order = ½ (8-0)= 4 (quadruple bond!!!)
F. Albert Cotton….
King of multiple metal-metal bonds!!
Example: dimerization of Mn2+
to form Mn24+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
pu (xz, yz)
d5
sg (z2)
Mn2+
Mn24+
d5
Mn2+
Bond order = ½ (10-0)= 5 (quintuple bond!!!)
Example: dimerization of Fe2+
to form Fe24+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
pu (xz, yz)
d6
sg (z2)
Fe2+
Fe24+
Bond order = ½ (10-2)= 4
d6
Fe2+
Example: dimerization of Hg2+
to form Hg24+
su* (z2)
pg* (xz, yz)
du* (xy, x2-y2)
dg (xy, x2-y2)
pu (xz, yz)
d10
sg (z2)
Hg2+
d10
Hg2+
Hg24+
Bond order = ½ (10-10)= 0 (No bond!!)