Isom
eris
m –
Ster
eois
omer
s:
Com
bina
tion
of C
hela
teR
ings
(∧, ∆
)C
oED
TA-
Not
cop
lana
r, no
t con
nect
ed a
t the
sam
e at
om
R1:
R2,
R3,
R4,
R5
XR
2: R
1, R
3, R
4, R
5
XX
XX
∆∧
∧
∧∆∧
, ∧
∧∆
, or ∆
∧∧
∆∧
6 C
N ;
Oct
ahed
ron,
Trie
thyl
ente
traa
min
e
H2N
H NN H
NH
2
Isom
eris
m –
Ster
eois
omer
s: L
igna
dR
ing
Con
form
atio
n
S S
∆ R R
∧
S S
∧ R R
∆
Isom
eris
m –
Ster
eois
omer
s: L
igna
dR
ing
Con
form
atio
n
Che
late
Rin
g C
onfo
rmat
ion
(λ, δ
)
6 C
N ;
Oct
ahed
ron,
Trie
thyl
ente
traa
min
e
Isom
eris
m –
Ster
eois
omer
s: L
igna
dR
ing
Con
form
atio
n
Che
late
Rin
g C
onfo
rmat
ion
(λ, δ
)
Isom
eris
m –
Con
stitu
tiona
l Iso
mer
s:H
ydra
te Is
omer
s
Hyd
rate
Isom
ers:
hav
ing
wat
er a
s ei
ther
a
ligan
dor
an
adde
d pa
rt o
f the
cry
stal
str
uctu
re
Isom
eris
m –
Con
stitu
tiona
l Iso
mer
s:Io
niza
tion
Isom
eris
m
Ioni
zatio
n Is
omer
s: E
xcha
nge
of io
nsbe
twee
n in
side
and
out
side
coo
rdin
atio
n sp
here
Isom
eris
m –
Con
stitu
tiona
l Iso
mer
s:C
oord
inat
ion
Isom
eris
m
Coo
rdin
atio
n Is
omer
s: re
quire
at l
east
two
met
al
Isom
eris
m –
Con
stitu
tiona
l Iso
mer
s:Li
nkag
e (a
mbi
dent
ate)
Isom
eris
m
Link
age
Isom
ers:
Com
poun
ds c
onta
inin
g am
bide
ntat
elig
and
thio
cyan
ate
nitr
ite
thio
cyan
ois
othi
ocya
no
nitr
oni
trito
Sep
arat
ion
Frac
tiona
l Cry
stal
izat
ion
–pa
ckin
g, s
olub
ility
, siz
e, c
harg
e
Chi
ralI
som
ers
Res
olut
ion
–ch
iralc
ount
erio
ns
Iden
tific
atio
n
X-r
ay c
ryst
allo
grap
hy
Opt
ical
rota
tory
disp
ersi
on (O
RD
)
Circ
ular
dic
hroi
sm(C
D)
Isom
eris
m –
Sepa
ratio
n an
d Id
entif
icat
ion
of Is
omer
s
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
s
Kno
wn
up to
16
CN
8≤
Pen
tago
nal b
ipyr
amid
, Cap
ped
trigo
nal
pris
m, C
appe
d oc
tahe
dron
7
Oct
ahed
ron,
Trig
onal
pros
m6
Trig
onal
bipy
ram
id, S
quar
e py
ram
id5
Tetr
ahed
ron,
Squ
are-
plan
e4
Trig
onal
-pla
ne3
Line
ar2
Rar
e1
Geo
met
ries
CN
Fact
ors
for S
truct
ures
1.N
umbe
r of B
onds
Bon
d fo
rmat
ion
is u
sual
ly
exot
herm
ic.
So
stab
ility
2.V
SE
PR
3.O
ccup
ancy
of d
orb
itals
Squ
are-
plan
ar v
sTe
trahe
dral
4.S
teric
Effe
cts
5.C
ryst
al P
acki
ng E
ffect
sC
ryst
allin
e La
ttice
vs
Sol
utio
n
Wha
t is
com
mon
thin
g?W
hich
one
is a
dom
inan
t fac
tor?
Stru
ctur
es v
sPr
oper
ties.
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
s
Oxi
datio
n St
ates
of T
rans
ition
Met
als
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
1,2
, and
3
CN
= 1
, Rar
e
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
1,2
, and
3
CN
= 2
, Rar
e, L
inea
r (D
∞h)
Mos
tly d
10m
etal
s, A
g(I),
Cu(
I), A
u(I),
Hg(
II)d5 ,
d6 , d7
Exa
mpl
es o
f CN
= 2
Larg
e Li
gand
sca
n in
duce
a li
near
arr
ange
men
t
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
1,2
, and
3
CN
= 3
, Rar
e, T
rigon
alpl
anar
(D3h
)M
ostly
d10
, PP
h 3, N
(SiM
e 3) 2
, B
ulky
eno
ugh,
Ste
ricef
fect
vs
Elec
troi
cst
ruct
ure
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
4
CN
= 4
, Tet
rahe
dral
(Td)
Squ
re-p
lana
r(D
4h)
Tetr
ahed
ral (
T d) ;
ver
y c
omm
on,
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
4
CN
= 4
, Tet
rahe
dral
(Td)
Squ
re-p
lana
r(D
4h)
Squr
e-pl
anar
(D4h
) ; m
ostly
d8
(Pd(
II), P
t(II),
Ni(I
I), A
g(III
), Ir(
I) R
h(I))
Tetr
ahed
ral v
sSq
uare
-pla
nar
Cou
nter
ion,
Cry
stal
Pac
king
Cl
Cu
Cl
ClC
l2C
s
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
4
CN
= 4
, Tet
rahe
dral
(Td)
Squ
re-p
lana
r(D
4h)
Squr
e-pl
anar
(D4h
) ; m
ostly
d8
(Pd(
II), P
t(II),
Ni(I
I), A
g(III
), Ir(
I) R
h(I))
Tetr
ahed
ral v
sSq
uare
-pla
nar
Cou
nter
ion,
Cry
stal
Pac
king
∆E
is n
ot b
ig.
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
5
CN
= 5
, Trig
onal
bipy
ram
id(D
3h),
Squa
re p
yram
id (C
4v)
Flux
iona
l beh
avio
r.
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
6
CN
= 6
, Oct
ahed
ral (
Oh)
mos
t com
mon
Oh
toD
4h
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
6
CN
= 6
, Oct
ahed
ral (
Oh)
to T
rigon
alPr
ism
(D3h
)
Usu
ally
with
thre
e bi
dent
ate
ligan
ds
πIn
tera
ctio
ns b
etw
een
adja
cent
sul
fur a
tom
s
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
7
CN
= 7
, Pen
tago
nal b
ipyr
amid
(Oh)
, Cap
ped
trig
onal
pris
m, C
appe
d oc
tahe
dron
Cap
ped
trigo
nalp
rism
Pen
tago
nal b
ipyr
amid
Cap
ped
octa
hedr
on
Diff
eren
t cou
nter
ion,
ste
ricre
quirm
ent
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N =
8
CN
= 8
, Squ
are
antip
rism
, Dod
ecah
edro
n
Eigh
t coo
rdin
atio
n is
rare
in
the
first
row
tran
sitio
n m
etal
s
Why
?
Cen
tral
ion
mus
t be
larg
e in
ord
er to
ac
com
mod
ate
eigh
t-co
ordi
natio
n
Squ
are
antip
rism
Dod
ecah
edro
n
Com
pres
sed
Squ
are
antip
rism
Coo
rdin
atio
n N
umbe
rs a
nd S
truc
ture
sC
N ≥
8
CN
≥8,
kno
wn
up to
16,
not
com
mon
Mul
timet
allic
Com
pexe
s
With
out d
irect
M-M
bon
d
With
dire
ct M
-M b
ond
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