om-2013-00277z Supporting Information
NHC Metal (Ag, Hg and Ni) Complexes Based on Quinoxaline-dibenzimidalium Salts: Synthesis, Structural Studies and Fluorescent Chemosensors for Cu2+ by Charge Transfer
Qing-Xiang Liu*, Zhao-Quan Yao, Xiao-Jun Zhao, Zhi-Xiang Zhao and Xiu-Guang Wang
Table of contents
1. Deriving the equation for 1:1 association curve fitting. 2. Tables S1-S3. 3. The figures of crystal structrures of 2b and 2c (Figure S1 and Figure S2). 4. The figures of fluorescence and UV/vis spectroscopies for 2a and 2c (Figure S3 and Figure S4). 5. The figures of 1H NMR, infrared and mass spectra for 2a, 2c, 2a/Cu2+ and 2c/Cu2+ (Figure S5-Figure S11). 6. The figures of 1H and
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C NMR spectra for organic intermediate and complexes
2a-2d. 7. The crystal packings of complexes 2a-2d.
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1. Deriving the equation for 1:1 association curve fitting RG
R+G
K
R is receptor, G is guest molecule or ion, and K is the association constant. The total concentration of the receptor is [R0], and the equilibrated concentrations of guest, receptor and RG following each titration are [G], [R] and [RG], respectively. [R0] = [R] + [RG] K = [RG]/[R][G] [RG] = K[R][G] When the absorbance of all the species is much less than 0.1, the fluorescence intensity is linearly proportional to the concentration of fluorescing species. Define F0 as the fluorescence intensity of the free receptor, and F as the fluorescence intensity of the receptor/guest complex: F0 = kr[R0] F = kr[R] + krg[RG] ∆F = F - F0 = kr[R] + krg[RG] - kr[R0] = kr([R0] – [RG]) + krg[RG] - kr[R0] = (krg - kr)[RG] To facilitate the deriving, to set up: ∆FN = (F - F0)/(Fmax – F0) ∆FN = (F - F0)/(Fmax – F0) = (krg - kr)[RG]/ (krg - kr)[RG]max = [RG]/[RG]max When the fluorescence intensity of receptor reach the max, [RG]max ≈ [R0] ∆FN = [RG]/[RG]max = [RG]/[R0] = [RG]/([R] + [RG]),
because
∆FN = K[R][G]/([R] + K[R][G]) = K[G]/(1 + K[G]) 1/∆FN = 1 + 1/K[G] 1/∆FN - 1 = 1/K[G] We get the logarithmic on the both side of this equation ln(1/∆FN - 1) = ln(1/K[G]) = -(lnK + ln[G]) To match with the symbol in the origin plots, to define ln[G] = X ln(1/∆FN - 1) = -(lnK + X) 1/∆FN – 1 = e-(lnK + X) ∆FN = 1/(1+ e-(lnK + X)) = (F - F0)/(Fmax – F0) 2
[RG] = K[R][G]
F = F0 + (Fmax – F0)/(1 + e-(lnK + X)) In this equation F and F0 are the fluorescence intensity of receptor in the presence and absence of guest, respectively, Fmax is final flourecence intensity in titration experiment, X means ln[G], and K is the association constant.
2. Tables S1-S3 Table S1. In the same ligand of 2a-2d, the dihedral angles (˚) between two benzimidazole rings (A), and the dihedral angles (˚) between quinoxaline ring and two benzimidazole rings (B) Complexes
A
B
2a 2b 2c 2d
35.6(1) 25.1(4) 24.9(1) 56.9(9)
77.4(1), 80.2(3) 81.3(7), 83.4(1) 68.8(1), 77.5(8) 83.9(1), 89.4(1)
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Table S2. Summary of crystallographic data for 2a and 2b 2a·CH3CN·C4H10O
2b·5H2O
C64H70N12Hg2O6P2F12
fw Cryst syst space group a/Å b/Å c/Å α/deg β/deg γ/deg V/Å3 Z Dcalcd, Mg/m3
C60H60Ag2F12N12P2 ·CH3CN·C4H10O 1569.05 Orthorhombic P212121 18.949(2) 13.064(1) 27.660(4) 90 90 90 6847.2(1) 4 1.522
13.077(1) 13.824(1) 14.191(1) 87.2(2) 72.1(2) 68.9(2) 2272.7(4) 1 1.424
Abs coeff, mm-1
0.704
0.704
F(000)
3196
974
Cryst size, mm
0.15 × 0.14 × 0.13
0.15 × 0.14 × 0.13
θmin, θmax, deg
1.47, 25.00
1.89, 25.01
T /K
296(2)
173(2)
no. of data collected
34655
11368
no. of unique data
12066
7881
no. of refined params
872
501
goodness-of-fit on F2 a
1.056
1.064
R1
0.0371
0.0349
wR2
0.0915
0.0966
R1
0.0411
0.0393
wR2
0.0944
0.0987
chemical formula
·8CH3OH 1948.69 Triclinic Pī
b
Final R indices [I > 2σ(I)]
R indices (all data)
a
GOF = [Σω(Fo2 - Fc2)2 /(n-p)]1/2, where n is the number of reflection and p is the
number of parameters refined.
b
R1 = Σ(||Fo| - |Fc||)/Σ|Fo|; wR2 =[Σ[w(Fo2 - Fc2)2 ]/
Σw(Fo2)2]1/2.
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Table S3． ．Summary of crystallographic data for 2c and 2d 2c·H2O
2d·4H2O·4(CH3)2SO
chemical formula
C36H28AgF6N8P·H2O
fw Cryst syst space group a/Å b/Å c/Å α/deg β/deg γ/deg V/Å3 Z Dcalcd, Mg/m3
843.52 Monoclinic C2/c 18.123(2) 23.008(3) 17.223(1) 90 90 90 7181.9(1) 8 1.560
C72H56Cl8N16Ni4 ·4H2O·4(CH3)2SO 2048.34 Monoclinic P21/c 17.979(8) 31.232(1) 15.858(7) 90 90 90 8905(8) 4 1.528
Abs coeff, mm-1
0.680
1.230
F(000)
3408
4224
Cryst size, mm
0.15 × 0.14 × 0.13
0.15 × 0.14 × 0.13
θmin, θmax, deg
1.43, 25.01
1.30, 25.00
T /K
173(2) K
173(2)
no. of data collected
17731
20388
no. of unique data
6272
4035
no. of refined params
499
322
goodness-of-fit on F2 a
1.073
1.160
R1
0.0795
0.1331
wR2
0.1937
0.2770
R1
0.0853
0.1574
wR2
0.1971
0.2939
b
Final R indices [I > 2σ(I)]
R indices (all data)
a
GOF = [Σω(Fo2 - Fc2)2 /(n-p)]1/2, where n is the number of reflection and p is the
number of parameters refined.
b
R1 = Σ(||Fo| - |Fc||)/Σ|Fo|; wR2 =[Σ[w(Fo2 - Fc2)2 ]/
Σw(Fo2)2]1/2.
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3. The figures of crystal structrures of 2b and 2c
Figure S1. Perspective view of 2c and anisotropic displacement parameters depicting 50% probability. All hydrogen atoms were omitted for clarity. Selected bond lengths (Å)
and
angles
(˚):
Ag(1)-C(16)
2.102(7),
Ag(1)-C(30A)
C(16)-Ag(1)-C(30A) 176.3(3), N(3)-C(16)-N(4) 106.8(6).
Figure S2.
A view of 2b along c axis.
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2.040(9);
4. The figures of fluorescence and UV/vis spectroscopies for 2a and 2c
Figure S3(a). UV/vis absorption change of 2a (1 × 10-5 mol/L) upon the addition of the nitrate salts of Li+, Na+, K+, NH4+, Ca2+, Al3+, Zn2+, Cd2+, Ag+, Pb2+, Co2+, Ni2+ and Cu2+ (5 × 10-5 mol/L) in acetonitrile at 25 ˚C.
Figure S3(b).
The curve of fluorescence intensity vs lnCCu at 495 nm for 2a; the 2+
curve fit using a 1:1 association equation (1).
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Figure S3(c). Emission (at 495 nm) of 2a at different concentrations of Cu2+ (0, 0.05, 0.1, 0.5, 1.0 µM) added, normalized between the minimum emission (0.0 µM Cu2+) and the emission (1.0 µM Cu2+). The detection limit was determined to be 5.0 × 10-8 mol/L.
Figure S3(d). Change ratio ((Fi-F0)/(FCu2+-F0)) of fluorescence intensity of 2a (1.0 × 10-5 mol/L) at 495 nm in various mixtures of metal ions (Cu(NO3)2 5.0 × 10-5 mol/L and another metal ion 5.0 × 10-5 mol/L). Background cations. 1: Cu2+; 2: Cu2+ + Li+; 3: Cu2+ + Na+; 4: Cu2+ + K+; 5: Cu2+ + NH4+; 6: Cu2+ + Ca2+; 7: Cu2+ + Al3+; 8: Cu2+ + Zn2+; 9: Cu2+ + Cd2+; 10: Cu2+ + Ag+; 11: Cu2+ + Pb2+; 12: Cu2+ + Co2+; 13: Cu2+ + Ni2+ in acetonitrile at 25 ˚C.
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Figure S4(a). UV/vis absorption change of 2c (1 × 10-5 mol/L) upon the addition of the nitrate salts of Li+, Na+, K+, NH4+, Ca2+, Al3+, Zn2+, Cd2+, Ag+, Pb2+, Co2+, Ni2+ and Cu2+ (5 × 10-5 mol/L) in acetonitrile at 25 ˚C.
Figure S4(b). Fluorescence intensity at 490 nm vs lnCCu for 2c; the curve fit using a 2+
1:1 association equation (1).
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Figure S4(c). Emission (at 490 nm) of 2c at different concentrations of Cu2+ (0, 0.01, 0.05, 0.1, 0.5, 1.0 µM) added, normalized between the minimum emission (0.0 µM Cu2+) and the emission (1.0 µM Cu2+). The detection limit was determined to be 1.0 × 10-8 mol/L.
Figure S4(d). Change ratio ((Fi-F0)/(FCu2+-F0)) of fluorescence intensity of 2c (1.0 × 10-5 mol/L) at 490 nm in various mixtures of metal ions (Cu(NO3)2 5.0 × 10-5 mol/L and another metal ion 5.0 × 10-5 mol/L). Background cations. 1: Cu2+; 2: Cu2+ + Li+; 3: Cu2+ + Na+; 4: Cu2+ + K+; 5: Cu2+ + NH4+; 6: Cu2+ + Ca2+; 7: Cu2+ + Al3+; 8: Cu2+ + Zn2+; 9: Cu2+ + Cd2+; 10: Cu2+ + Ag+; 11: Cu2+ + Pb2+;
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12: Cu2+ + Co2+; 13: Cu2+ + Ni2+ in acetonitrile at 25 ˚C.
5. The figures of 1H NMR, infrared and mass spectra for 2a, 2c, 2a/Cu2+ and 2c/Cu2+
Figure S5. 1H NMR (400 MHZ, DMSO-d6): the changes of 1H NMR spectra in aromatic rings for 2a and 2a/Cu2+. a: complex 2a, b: 2a/Cu2+.
Figure S6. 1H NMR (400 MHZ, DMSO-d6): the changes of 1H NMR spectra in aromatic rings for 2c and 2c/Cu2+. a: complex 2c, b: 2c/Cu2+.
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Figure S7. Infrared spectra of Cu(NO3)2.
Figure S8. Infrared spectra of complex 2a and 2a/Cu(NO3)2.
Figure S9. Infrared spectra of complex 2c and 2c/Cu(NO3)2.
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Figure S10. Mass spectrum of complex 2a. MS (EI): m/z {[M-2(PF6-)]/2}+ = 582.45.
Figure S11. Mass spectrum of complex 2c. MS (EI): m/z {[M-2(PF6-)]/2}+ = 680.60.
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6. The Figures of 1H and
13
C NMR spectra for organic intermediate and
complexes 2a-2d
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15
16
17
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7. The crystal packings of complexes 2a-2d. The Crystal Packings of Complexes 2a-2d. In the crystal packing of 2a (Figure S12(a)), 2D supramolecular layer is formed by cations and PF6- through C-H···F hydrogen bonds1 and C-H···π contacts.2 In the C-H···F hydrogen bonds, the hydrogen atoms are from benzimidazole rings (the data of hydrogen bonds being given in Table S4). In the C-H···π contacts, the hydrogen atoms are from benzimidazole rings and π systems are from benzene groups of quinoxalines (the data of C-H···π contacts being given in Table S5). In addition, 2D supramolecular layers are further extended into 3D 19
supramolecular architecture through new C-H···F hydrogen bonds (Figure S12(b)). In the new hydrogen bonds, the hydrogen atoms are from quinoxalines. In the crystal packing of 2b (Figure S13(a)), 2D supramolecular layer is formed through π-π stacking interactions from intermolecular benzimidazole rings.3 Interestingly, 2D supramolecular layers are further extended into 3D supramolecular architecture (Figure S13(b)) through
new π-π stacking interactions from
intermolecular benzimidazole rings (the data of π-π stacking interactions being given in Table S5). In the crystal packing of 2c (Figure S14(a)), 2D supramolecular layer is formed through π-π stacking interactions from intermolecular benzimidazole rings (Table S5). In the crystal packing of 2d (Figure S15(a)), 2D supramolecular layer is formed by π-π stacking interactions from intermolecular pyridine rings and C-H···π contacts. In this C-H···π contacts, the hydrogen atoms are from benzimidazole rings and π systems are from the benzene rings of quinoxalines. Additionally, the anionic unit [NiCl4]2- are packed between successive 2D supramolecular layers and hold layers together via C-H···Cl hydrogen bonds4 to form 3D supramolecular architecture (Figure S15(b)). In the hydrogen bonds, the hydrogen atoms are from CH2 of PyCH2 and chlorine atoms are from [NiCl4]2-.
References 1 Wei, W.; Wu, M. Y.; Huang, Y. G.; Gao, Q.; Jiang, F. L.; Hong, M. C. Z. Anorg. Allg. Chem. 2008, 634, 2623. 2 Bettens, R. P. A.; Dakternieks, D.; Duthie, A.; Kuan, F. S.; Tiekink, E. R. T. CrystEngComm 2009, 11, 1362. 3 Chong, Y. S.; Carroll, W. R.; Burns, W. G.; Smith, M. D.; Shimizu, K. D. Chem. Eur. J. 2009, 15, 9117. 4 Cole, M. L.; Junk, P. C. CrystEngComm 2004, 6, 173.
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Table S4. H-Bonding geometry (Å, ˚) for complexes 2a and 2d Complexes
D-H···A i
C(6)-H(6)···F(11) C(16)-H(16)···F(8)ii C(9)-H(9)···F(12)ii C(6)-H(6A)···Cl(2)ii
2a 2d
D-H
H···A
D···A
D-H···A
0.929(5) 0.929(5) 0.930(4) 0.988(1)
2.423(2) 2.444(2) 2.437(2) 2.690(2)
3.269(5) 3.254(6) 3.202(5) 3.656(1)
151.2(3) 145.5(3) 139.4(2) 165.6(6)
Symmetry code: i: 1 + x, 0.5 + y, 1.5 - z; ii: 1.5 - x, - y, -0.5 + z for 2a. ii: 0.5 + x, 0.5 + y, -1 + z for 2d.
Table S5. Distances (Å) of π-π interactions, and distances (Å) and angles (°) of C-H···π contacts for 2a-2d π-π Complex
Face-to-face
2a 2b
_ 3.484(7) (benzimidazole) 3.441(8) (benzimidazole) 3.463(9) (benzimidazole) 3.579(1) (pyridine)
2c 2d
C-H···π Center-to-center _ 3.894(3) (benzimidazole) 3.601(4) (benzimidazole) 3.616(4) (benzimidazole) 3.787(1) (pyridine)
H···π
C-H···π
2.891(4) _
143.5(2) _
_ 3.174(1)
_ 106.4(5)
Figure S12(a). 2D supramolecular layer of 2a via C-H···F hydrogen bonds and C-H···π constacts. All hydrogen atoms except those participating in the C-H···F hydrogen bonds and C-H···π constacts were omitted for clarity.
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Figure S12(b). 3D supramolecular architecture of 2a via C-H···F hydrogen bonds and C-H···π constacts. All hydrogen atoms except those participating in the C-H···F hydrogen bonds and C-H···π constacts were omitted for clarity.
Figure S13(a). 2D supramolecular layer of complex 2b via π-π interactions. All hydrogen atoms were omitted for clarity.
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Figure S13(b). 3D supramolecular network of complex 2b via π-π interactions. All hydrogen atoms were omitted for clarity.
Figure S14(a). 2D supramolecular layer of complex 2c via π-π interactions. All hydrogen atoms were omitted for clarity.
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Figure S15(a). The 2D supramolecular layer of complex 2d via C-H···π constacts and π-π interactions. All hydrogen atoms except those participating in the C-H···π constacts were omitted for clarity.
Figure S15(b).
3D supramolecular architecture of complex 2d via C-H···Cl
hydrogen bonds, C-H···π constacts and π-π interactions. All hydrogen atoms except those participating in the C-H···Cl hydrogen bonds and C-H···π constacts were omitted for clarity.
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