Transcript Презентация PowerPoint - u

Nikolaev Institute of Inorganic Chemistry
Russian Academy of Sciences, Siberian Branch
Novosibirsk
Inclusion of metal-organic complexes
into cucurbit[8]uril
Vladimir P. Fedin, Tatiana V. Mitkina, Olga A. Gerasko
Moscow
2005
2
The cucurbit[n]uril family (CB[n])
R. Behrend, E. Meyer, F. Rusche, Liebigs Ann. Chem. 1905,
339, 1.
W. A. Freeman, W. L. Mock, N. Y. Shih, J. Am. Chem. Soc.
2
The cucurbit[n]uril family (CB[n])
82
164
280
Cavity volume (Å3)
480
Electrostatic potential maps for a) -CD and b)
CB[7] The red to blue color range spans –80 to 40 kcal
mol-1.
(K. Kim et al., Acc. Chem. Res. 2003, 36, 621)
CB[n]s exhibit a pronounced preference to interact with
cationic rather than neutral or anionic guests whereas
CDs prefer to bind to neutral or anionic rather than
cationic guests.
2
The cucurbit[n]uril family (CB[8])
Guests:
17.5 Å
NH HN
M
NH
8.8 Å
NH
NH
H2N
M
L
9.1 Å
6.9 Å
NH2
L
L
cucurbit[n]uril
С6nH6nLN4nO2n
NH
HN
n = 5M  10
NH
H ND
symmetry
nh
2
dimensions of CB[8]
molecule
2
2
2
L
cucurbit[8]uril (CB[8])
C48H48N32O16
3
Possible approaches to synthesis of
inclusion compounds of metal-organic
complexes into CB[8]
1) “metal aqua-complex + ligand@CB[8]” scheme
2) direct reaction “host + guest”
3) “guest substitution” approach
4
1) The approach “metal aqua-complex +
ligand@CB[8]”
Synthesis of {[Ni(cyclam)]@CB[8]}Cl2 ·16H2O
HN
HN
H
N
NH
cyclam@CB[8]·
4HCl18H2O
+
Ni2+
12-fold excess of
NiCl2·6H2O
Aqueous
solution, reflux,
100°C, 2 h.
N
N
Ni
N
N
yellow crystals,
yield = 89%,
hot water soluble
5
The structure of {[Ni(cyclam)]@CB[8]}Cl2·16H2O
D
Absorption spectra comparison:
0,4
{[Ni(cyclam)]@CB[8]}Cl2*16H2O
[Ni(cyclam)](ClO4)2
0,3
0,2
0,1
side view
 ESI-MS: m/z = 793.245
{[Ni(cyclam)] + CB[8]}2+
 IR: CB[8] vibrations
0,0
300
400
500
600
700
wavelength, nm
800
 X-ray: square-planar
environment of NiII; the angle
between NiN4 plane and
equatorial plane of CB[8] ~ 70°
6
NiII/NiIII
oxidation within the CB[8] cavity.
Synthesis of {[NiIII(cyclam)]@CB[8]}(SO4)1.5·14⅔H2O
{[NiII(cyclam)]@CB[8]}2+ + Ce4+  {[NiIII(cyclam)]@CB[8]}3+ + Ce3+
ESR
hyperfine
structure
 X-ray cryst.: square-planar
environment of NiIII; the angle
between NiN4 plane and equatorial
plane of CB[8] ~ 70°
 IR: CB[8] vibrations, (SO42-) = 1121,
619 cm-1
 Solid-state ESR: low spin (S = ½) d7
square-planar NiIIIN4 (!),
А = 286 G, gx = 2.142, gy = 2.277,
gz = 2.209.
 greenish-yellow crystals, waterinsoluble, yield 88%
2) Direct approach “host + guest”
2+
N
N
Ni
N
N
cucurbit[8]uril
7
2) Direct approach “host + guest”
8
Synthesis of {trans-[M(en)2X2]@CB[8]}Cln·mH2O
(M = CuII, NiII, CoIII ; X = Cl-, H2O)
2+
OH2
NH2
H2N
NH2
H2N
H2N
OH2
NH2
2+
OH2
NH2
H2N
Ni
Co
Cu
NH2
+
Cl
H2N
Cl
cucurbit[8]uril
NH2
H2N
OH2
2) Direct approach “host + guest”
9
Synthesis of {trans-[Co(en)2Cl2]@CB[8]}Cl·17H2O
+
Cl
NH2
Selective inclusion of trans-isomer !
H2N
Co
NH2
H2N
Cl
+
trans
+
+
CB[8]20H2O
H2N
NH2
Co
Cl
Cl
cis
H2N
Cl
H2N
H2N
Cl
Co
NH2
+
H2N
H2N
Aqueous
solution, reflux,
100°C, 2 h.
dark-green crystals,
yield = 97%,
hot water soluble
Orientations of the ethylenediamine
complexes inside the cavity of CB[8]
Cu
10
Co
Ni
Cl
aq
aq
{[Cu(en)2(H2O)2]@CB[8]}2+ {[Ni(en)2(H2O)2]@CB[8]}2+
= 0°,
Cu–N 2.00 Å,
Cu–O 2.55 Å
= 16°,
Ni–N 2.10 Å,
Ni–O 2.13 Å
{[Co(en)2Cl2]@CB[8]}+
= 90°,
Co–N 1.92 Å,
Co–Cl 2.24 Å
Distortion of CB[8] molecule
upon encapsulation of guests
13.01 Å
11.46 Å
Cu
Ni
13.43 Å
14.38 Å
trans-{[Cu(en)2(H2O)2]@CB[8]}2+
trans-{[Ni(en)2(H2O)2]@CB[8]}2+
 = 0.42 Å (Cu–N = 2.00 Å)
 = 2.92 Å (Ni–N = 2.10 Å)
Solution and solid state studies of {trans[M(en)2X2]@CB[8]}Cln·mH2O
(M = CuII, NiII, CoIII ; X = Cl-, H2O)
Cu
Cu
Ni
 X-ray cryst., elemental analysis
 ESI-MS: m/z = 756
{CB[8] + Cu(en)2}2+
 ESR: g|| = 2.212, g = 2.049
 IR: CB[8] vibrations
Co
Co
 Dissociation upon dissolution in
water:
{[Cu(en)2(H2O)2]@CB[8]}2+
[Cu(en)2(H2O)2]2+ + СB[8]
11
12
Solution and solid state studies of {trans[M(en)2X2]@CB[8]}Cln·mH2O
(M = CuII, NiII, CoIII ; X = Cl-, H2O)
Cu
Cu
 X-ray cryst., elemental analysis
 ESI-MS: m/z = 510
{CB[8] + Ni(en)2 + Na}3+
Ni
Co
Co
 1H NMR: CB[8] resonanses became
broadened and en signals
disappeared upon inclusion
 IR: CB[8] vibrations
 Stable in solution
 May undergo reactions of guest
substitution
2X + {Y@CB[8]}
X=
 Y + {(X)2@CB[8]}
N
C
N
13
Solution and solid state studies of {trans[M(en)2X2]@CB[8]}Cln·mH2O
(M = CuII, NiII, CoIII ; X = Cl-, H2O)
Cu
Cu

X-rayspectra
cryst.,comparison:
elementalhypsochromic
analysis
Absorption
schift upon inclusion
2+

ESI-MS:
m/z
=
754
{CB[8]
+
Co(en)
}
2
e, л/моль*см
50
trans-[Co(en)2Cl2]
 IR: CB[8] vibrations
Ni
+
{trans-[Co(en)2Cl2]@CB[8]}
40
 transcis isomerization
°С, 45 hours)
(120
30
3+
H2N
H2N
Co
Co
H2N
10
H2N
H2N
Cl
Co
Cl
H2N
NH2
Co
+
20
+
OH2
OH2
+
NH2
0
350
400
450
500
550
600
650
700
l , нм
1H
NMR-spectra comparison of D2O solutions of
[trans-Co(en)2Cl2]Cl
and {[trans-Co(en)2Cl2]@CB[8]}Cl·17H2O
CB[8]
CB[8]
en resonanses are
strongly upfield-shifted
upon inclusion
CB[8]
NH2
(en)
CH2
(en)
+
H2N
Cl
H2N
Cl
Co
H2N
NH2
inclusion
compound
+
Cl
 = - 0.85 ppm
 = - 0.63 ppm
NH2
H2N
Co
NH2
H2N
Cl
14
Thermogravimetric data for {[trans-Co(en)2Cl2]@CB[8]}Cl·17H2O,
trans-[Co(en)2Cl2]Cl and CB[8]17H2O samples
TG,
TG, mg
mg T(decomposition of trans-[Co(en)2Cl2]Cl) increased
120
by 135°С upon inclusion into CB[8]
120
100
100
80
80
||
225°
225°
60
60
360°
|
360°
||
+
40
40
H2N
20
20
Cl
00
-20
-20
H2N
Cl
Co
H2N
NH2
medium: argon
100
100
200
200
300
300
300
400
400
400
500
500
500
600
600
600
700
700
700
800
800
800
Co(en)22Cl
@CB[8]}Cl*17H22OO
trans
trans--[[Co(en)
Cl22]]]@CB[8]}Cl*17H
Cl
CB[8]*17H
trans
-[Co(en)
2O
2Cl2]Cl
trans-[Co(en)2Cl2]Cl
900
900
900
1000
1000
1000
t,t,t,oooCCC
+
Cl
NH2
H2N
Co
NH2
H2N
Cl
3) “Guest substitution” approach
Synthesis of
{[Cu(dien)(4,4’-bipy)(H2O)]2@СB[8]}(ClO4)4·11H2O
16
NH
2+
H2N
NH
2+
NH
HN
Ni
NH
HN
H2N
Cu
N
+
2
NH2
Cu
OH2
NH2
N
N
4+
OH2
Water solution,
reflux, 100°C,
3 h.
+
N
N
H2O
N
Cu
NH2
{[Ni(cyclam)]@
CB[8]}Cl2 ·16H2O
10-fold excess of
[Cu(dien)(4,4’-bipy)
(H2O)](ClO4)2
H2N
NH
Violet crystals, yield 60%
2+
NH
HN
Ni
NH
HN
17
The X-ray crystal structure of
{[Cu(dien)(4,4’-bipy)(H2O)]2@СB[8]}(ClO4)4·11H2O
 X-ray cryst. structure,
elemental analysis
 Absorption spectra: l (e): 600
(185), 270 (sh), 240 (46200)
( = l,  e of free guest)
 ESI-MS: m/z = 825.8
{CB[8] + Cu(dien)(4,4´-dipy)}2+
 Solid-state ESR: gz = 2.312, gx
= gy = 2.045 (g|| = 2.24, g = 2.06
for free guest) – Cu-OH2 become
longer
 IR: vibrations of CB[8],
(С=С) and (С=N) 4,4´-dipy,
(R2N-H) dien, (ClO4-)
18
Conclusions
Inclusion into the cavity of cucurbit[8]uril
may be helpful for:
1) isolation of metal complexes with unusual
oxidation states and coordination
environments
2) stabilization of guest complexes in solid
state and in solution towards thermolysis,
isomerization etc.
Tatiana V. Mitkina
Dr. Olga A. Gerasko
19
Acknowledgement
 RFBR
 INTAS (Prof. F. Secheresse)
 RAS Target Programme (Prof. A.I. Konovalov)