Transcript Document

Synthesis and Spectroscopic Analysis of Therapeutic Ru(II) Complexes
Samar Moqadasi,a,b Laura Perdisatt,a Christine O’Connor,a,b and Luke O’Neill.a,b
aSchool
of Chemical and Pharmaceutical Sciences, Kevin Street, bMaterials Synthesis and Applications (MSA) Research Group, FOCAS
Institute, Dublin Institute of Technology, Dublin 8, Ireland.
[email protected]
Previous work carried out on similar complexes has shown promising results. 2,3 The ligands of
interest and the corresponding complexes are listed in table 1 and the structure of the resulting
Ru(II) complex is given in figure 1.
INTRODUCTION
The aim of this study is to synthesise and characterise new ligands based on a
1,10-Phenanthroline-5,6-dione backbone and their respective Ru(II)
complexes; Ru(bpy)2mfmp, Ru(bpy)2fmp and Ru(bpy)2NO2-mp as shown in
figure 1.The synthesis of the ligands will be discussed and a variety of Ru(II)
complexes. A brief insight of the electronic and NMR spectroscopy will be
presented along with preliminary photochemical results such as extinction
coefficients, quantum yields and luminescence lifetimes.
R1
Ruthenium complexes have well established synthetic and photochemical
properties.1The objective of this work is to synthesise Ru(II) complexes for the
applications of potential therapeutics. In order to establish their uses in
medicinal applications we must first ensure their purity and photochemical
properties.
O
CHO
Ru(bpy)2mfmp
Ru(bpy)2fmp
Ru(bpy)2NO2-mp
mfmp
fmp
NO2-mp
CHO
H
H
H
CHO
NO2
R2
Ru
N
N
2h reflux
N
N
N
RuL2Cl2 +
N
N
R1
8 hrs. reflux
50cm3(ethanol/water)
R1
R2
N
N
N
NH
N
CH3COOH
N
N
phen-dione
R2
The respective Ru(II) complexes were prepared as shown in Figure
3 and isolated as a PF6 salt.
R2
R2
CH3COONH4
+
R1
N

dione backbone. Figure 2 depicts the synthetic route of the ligands.
R1
Ligands
N
N
Table 1. The complexes and ligands investigated in this research.
 The ligands have been synthesised based on a 1,10-phenanthroline-5,6O
Complexes
N
Figure 1. The Ru(II) complex structure.
EXPERIMENTAL
R2
N
N
N
Ru
N
N
N
N
N
L= bpy
R1
NH
Figure 3. Synthetic route for the Ru(II)complexes
N
Figure 2. Synthetic route for the ligands
Ligand
R1
mfmp
Table 2. The ligands synthesised in this research.
R2
CHO
fmp
R2
H
H
NO2-mp
R1
All ligands are recrystallised from hot ethanol
and the complexes from acetone/water.
CHO
H
N
N
N
Ru
N
N
N
L= phen
NO2
RESULTS
An example of a 1H NMR COSY and HSQC NMR is given for the complex [Ru(bpy)2NO2-mp]. The COSY spectrum shown in Figure 4 confirms 1H NMR assignment for this complex and
HSQC in Figure 5 gives further support to 13C NMR assignment.
8
NO2
7
5
4
6
N
10
N
NH
11
N
Ru
1
N
3
N
9
N
2
N
Figure 5.
1H
NMR-13C NMR HSQC (400 MHz, DMSO-d6) [ppm] of spectrum of [Ru(bpy)2NO2-mp]
Figure 4. 1H NMR-COSY (400 MHz, DMSO-d6) [ppm] of spectrum of [Ru(bpy)2NO2-mp]
Initial electronic spectroscopy results have been carried out in Acetonitrile. The results for absorption and emission studies and their respective extinction coefficient and quantum yield are
presented in table 3.
Complex
Abs λmax(nm)
-3
-1
[ε](mol dm cm )
Emission
λmax(nm)
[Фf]
Ru(bpy)2fmp
Ru(bpy)2mfmp
Ru(bpy)2NO2-mp
Std: Ru(bpy)3Cl2
457 (10,600)
457 (12,480)
456 (22,480)
451 (12,108)
597 [0.093]
597 [0.067]
600 [0.011]
602 [0.062]
Luminescence
Lifetime, τ (ns)
[Nd: YAG laser]
*
degassed
*
160 (204)
*
183 (286)
*
102 (164)
*
320 (219)
Luminescence
Lifetime, τ (ns)
[TCSPC]
176
254
162
215
Table 3. Absorption, emission, extinction coefficient, quantum yield and luminescent lifetimes (aerated and *degassed) by Nd: YAG laser
and Time Correlated Single Photon Counting in Acetonitrile.
CONCLUSION
The preliminary spectroscopic results such as IR,1H NMR & 13C NMR suggest the
complexes and their associated ligands are pure after recrystallisation. The absorption
and emission studies were completed on 3 of the Ru(II) complexes and from this the
extinction coefficients and quantum yields were calculated. The luminescent lifetimes
were determined for each of the ruthenium (II) complexes by two laser techniques (Nd:
YAG and TCSPC).
REFERENCES
1. V. Balzani, A. Credi, M. Venturi, Coord. Chem. Rev., 1998, 171, 3-16.
2. G. J. Ryan, S. Quinn, T. Gunnlaugsson, Inorg. Chem., 2008, 47, 401-403.
3. K. A. O’Donoghue, J. M. Kelly, P. E. Kruger, Dalton Trans., 2004, 13-15.
ACKNOWLEDGMENTS
Many thanks to my supervisor, Dr. Christine O’Connor, also special thanks to Dr. Luke O’Neill and Laura
Perdisatt for all their help.
Strand 1 R & D funding 2006, Technological Sector Research Initiative NDP 2000-2006.