Supporting Information for A Selective, Sensitive, Colorimetric and Fluorescence Probe for Relay Recognition of Fluoride and Cu (II) ions with OFF-ON-OFF Switching in Ethanol-Water Solution Yu Peng,* Yu-Man Dong, Ming Dong and Ya-Wen Wang* State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (P. R. China) pengyu@lzu.edu.cn ywwang@lzu.edu.cn Table of Contents 1. 2. 3. 1 H, 13 C NMR and ESI-MS copies of the compound 3 (Figures S1-S3)...S3 1 H, 13 C NMR, IR, ESI-MS and HRMS copies of the probe 1 (Figures S4-S8)..S6 1 H, 13 C NMR, IR and ESI-MS copies of the compound 2 (Figures S9-S12)...S11 4. Fluorescence spectral changes of 1 + F system with various anions in ethanolwater solution (Figure S13)...S15 5. The ph dependence of the fluorescence intensity change of 1 and 1 + F system (Figure S14)...S16 6. The detection limit of the probe 1 with F in ethanol-water solution (Figure S15)...S17 7. The kinetic study of the response of F to 1 in ethanol-water solution at 25 C (Figure S16)...S18 8. Job s plot for 1 + F system with Cu 2+ in ethanol-water solution (Figure S17)....S19 9. ESI-MS spectrum of 2 with Cu 2+ in ethanol-water solution (Figure S18)...S20 10. Benesi-Hildebrand plots of 1 + F system with Cu 2+ in ethanol-water solution (Figure S19)...S21 11. The detection limit of the 1 + F system with Cu 2+ in ethanol-water solution S1
(Figure S20)......S22 12. Plots of fluorescence intensity against time for 1 + F system upon addition of Cu 2+ (Figure S21)...S23 13. The UV-vis spectra of 1, 1 + F, 1 + F + Cu 2+ and 1 + F + cations in ethanol-water solution (Figures S22 and S23).......S24 14. The changes of UV-vis spectra of 1 + F system upon addition of Cu 2+ in ethanol-water solution (Figure S24)....S26 15. Fluorescence spectra of 1 and 1 + F in ethanol with different proportions of H 2 O (Figure S25)...S27 16. The detection limit of the probe 1 with F in ethanol (Figure S26)...S28 17. The kinetic study of the response of F to 1 in ethanol at 25 C (Figure S27).. S29 18. The UV-vis spectra of 1 with various anions in ethanol (Figure S28)....S30 19. Fluorescence spectra of 2 and 2 + Cu 2+ in ethanol with different proportions of H 2 O (Figure S29)...........S31 20. The ph dependence of the fluorescence intensity change of 2 and 2 + Cu 2+ (Figure S30)...... S32 21. The detection limit of the 2 with Cu 2+ in water solution (Figure S31)..S33 22. Job s plot for 2 with Cu 2+ in water solution (Figure S32)...S34 23. Benesi-Hildebrand plots of 2 with Cu 2+ in water solution (Figure S33)...S35 24. Fluorescence spectral changes of 2 with various ions in water solution (Figures S34 and S35)...S36 25. Plots of fluorescence intensity against time for 2 upon addition of Cu 2+ (Figure S36)...S38 26. The changes of UV-vis spectra of 2 upon addition of various cations in water solution (Figures S37 and S38)...S39 27. ORTEP plot of 1 (Figure S39)...S41 28. Optimized structures, cartesian coordinates and computed total energies of 1, 2 2 Cu 2+ and [2 Cu 2+ ] (Figures S40-S43)...S42 29. HOMO-LUMO energy levels and the molecular orbital plots of [2 Cu 2+ ] (Figure S44)......S50 S2
1. 1 H, 13 C NMR and ESI-MS copies of the compound 3. CHO Et 2 N 3 OTBS Figure S1. 1 H NMR (CDCl 3, 400 MHz) spectrum of 3. S3
CHO Et 2 N 3 OTBS Figure S2. 13 C NMR (CDCl 3, 100 MHz) spectrum of 3. S4
[M + H] + CHO Et 2 N 3 OTBS Figure S3. ESI mass spectrum of 3. S5
2. 1 H, 13 C NMR, IR, ESI-MS and HRMS copies of the probe 1. S Et 2 N CN O TBS 1 N Figure S4. 1 H NMR (CDCl 3, 400 MHz) spectrum of 1. S6
S Et 2 N O TBS 1 CN N Figure S5. 13 C NMR (CDCl 3, 100 MHz) spectrum of 1. S7
S Et 2 N O TBS 1 CN N Figure S6. IR spectrum of 1. S8
[M + H] + S Et 2 N CN O TBS 1 N Figure S7. ESI mass spectrum of 1. S9
[M + H] + [M + Na] + Figure S8. HRMS of 1. S10
3. 1 H, 13 C NMR, IR and ESI-MS copies of the compound 2. S N Et 2 N O 2 C NH Figure S9. 1 H NMR (CDCl 3, 400 MHz) spectrum of 2. S11
S N Et 2 N O 2 C NH Figure S10. 13 C NMR (CDCl 3, 100 MHz) spectrum of 2. S12
S N Et 2 N O 2 C NH Figure S11. IR spectrum of 2. S13
[M + H] + S N Et 2 N O 2 C NH Figure S12. ESI mass spectrum of 2. S14
4. Fluorescence spectral changes of 1 + F system with various anions in ethanol-water solution. Figure S13. Fluorescence spectral changes of 1 + TBAF (25.0 µm + 125.0 µm) with various anions (125.0 µm) in ethanol-water (v/v = 1:1) solution (λ ex = 460 nm). S15
5. The ph dependence of the fluorescence intensity change of 1 and 1+F system. Figure S14. Fluorescence intensity 1 (25.0 µm) in ethanol-water (1:1, v/v) solution of different ph in the absence (square) and presence (dot) of 25.0 µm F, respectively (λ ex = 460 nm). S16
6. The detection limit of the probe 1 with F in ethanol-water solution. Figure S15. Plot of the intensity at 523 nm for a mixture of probe 1 (25.0 µm) and F in ethanol-water (v/v = 1:1) solution in the range 0 2.5 µm (λ ex = 460 nm). The result of the analysis as follows: Linear Equation: Y = 67.4182 X +19.9091 R = 0.9976 S = 6.74 10 7 δ = ( F0 N 1 LOD = K δ / S = 1.177 10-7 M F 0 is the fluorescence intensity of 1. 2 F0 ) = 2.5467 (N = 10) K = 3 S17
7. The kinetic study of the response of F to 1 in ethanol-water solution at 25 C. Figure S16. The kinetic study of the response of 1 (25.0 µm) to F (250.0 µm) in ethanol-water (v/v = 1:1) solution at 25 o C under pseudo-first-order condition. S18
8. Job s plot for 1 + F system with Cu 2+ in ethanol-water solution. Figure S17. Job s plot for 1 + F with Cu 2+ in ethanol-water (v/v = 1:1) solution. S19
9. ESI-MS spectrum of 2 with Cu 2+ in ethanol-water solution. [2 + Cu + ClO 4 ] + Figure S18. ESI-MS spectrum of 2 with Cu 2+ in ethanol-water (v/v = 1:1) solution. S20
10. Benesi-Hildebrand plots of 1 + F system with Cu 2+ in ethanol-water solution. Figure S19. Benesi-Hildebrand plot of 1+ F, assuming 1:1 stoichiometry for association between 1 + F and Cu 2+ in ethanol-water (v/v = 1:1) solution. The binding constant was determined using a reported procedure for a 1:1 binding mode. The result of the analysis as follows: Equation: Y = A +B X Y = 5.8995 1.2178 X R = 0.9916 F F lg F F max = lg K + lg[cu min 2+ K =7.93 10 5 M -1 ] S21
11. The detection limit of the 1 + F system with Cu 2+ in ethanol-water solution. Figure S20. Plot of the intensity at 544 nm for a mixture of 1 + F and Cu 2+ in ethanol-water (v/v = 1:1) solution in the range 0 2.5 µm (λ ex = 460 nm). The result of the analysis as follows: Linear Equation: Y = 57.1636 X+1662.090 R = 0.9931 S = 5.72 10 7 δ = ( F0 1 N 2 F0 ) LOD = K δ / S = 1.786 10-6 M F 0 is the fluorescence intensity of 1 + F. = 34.034 (N = 10) K = 3 S22
12. Plots of fluorescence intensity against time for 1 + F system upon addition of Cu 2+. Figure S21. Plots of fluorescence intensity against time for 1+ F upon addition of 1.0 equiv of molar ratio of Cu 2+ in ethanol-water (v/v = 1:1) solution. S23
13. The UV-vis spectra of 1, 1 + F, 1 + F + Cu 2+ and 1 + F + cations in ethanol-water solution. Figure S22. UV-vis spectra of 1 (25.0 µm), 1 + F (25.0 µm + 25.0 µm), and 1 + F + Cu 2+ (25.0 µm + 25.0 µm + 25.0 µm) in ethanol-water (1:1, v/v) solution. S24
Figure S23. UV-vis spectra of 1 + F (25.0 µm + 25.0 µm), and 1 + F + cations (25.0 µm + 25.0 µm + 125.0 µm) in ethanol-water (1:1, v/v) solution. S25
14. The changes of UV-vis spectra of 1 + F system upon addition of Cu 2+ in ethanol-water solution. Figure S24. UV-vis spectra of 1 + F (25.0 µm + 25.0 µm) upon the addition of Cu 2+ in ethanol-water (1:1, v/v) solution. S26
15. Fluorescence spectra of 1 and 1 + F in ethanol with different proportions of H 2 O. Figure S25. Fluorescence spectra of 1 (25.0 µm) and 1 (25.0 µm) + F (25.0 µm) in ethanol with different proportions of H 2 O (λ ex = 460 nm). S27
16. The detection limit of the probe 1 with F in ethanol. Figure S26. Plot of the intensity at 510 nm for a mixture of probe 1 (25.0 µm) and F in ethanol in the range 0 2.5 µm (λ ex = 460 nm). The result of the analysis as follows: Linear Equation: Y = 0.6818+33.945 X R = 0.99812 S = 3.3945 10 7 δ = ( F0 N 1 LOD = K δ / S = 1.958 10-8 M F 0 is the fluorescence intensity of 1. 2 F0 ) = 2.2161 (N = 10) K = 3 S28
17. The kinetic study of the response of F to 1 in ethanol at 25 C. Figure S27. The kinetic study of the response of 1 (25.0 µm) to F (250.0 µm) in ethanol at 25 o C under pseudo-first-order condition. S29
18. The UV-vis spectra of 1 with various anions in ethanol. 3.0 Absorbance 2.5 2.0 1.5 1.0 0.5 1+NaF 1+TBAF 1, 1+other anions 0.0 250 300 350 400 450 500 550 600 Wavelength (nm) Figure S28. UV-vis spectra of 1 (25.0 µm) with various anions (F, Cl, Br, I, AcO, ClO 4, CF 3 SO 3, NO 3, HSO 4, H 2 PO 4, BF 4, N 3, CN, SCN, and OH, 100.0 µm) in ethanol. S30
19. Fluorescence spectra of 2 and 2 + Cu 2+ in ethanol with different proportions of H 2 O. Figure S29. Fluorescence spectra of 2 (25.0 µm) and 2 (25.0 µm) + Cu 2+ (25.0 µm) in ethanol with different proportions of H 2 O (λ ex = 460 nm). S31
20. The ph dependence of the fluorescence intensity change of 2 and 2 + Cu 2+. Figure S30. Fluorescence intensity 2 (25.0 µm) in H 2 O solution of different ph in the absence (square) and presence (dot) of 25.0 µm Cu 2+, respectively (λ ex = 460 nm). S32
21. The detection limit of the 2 with Cu 2+ in water solution. Figure S31. Plot of the intensity at 533 nm for a mixture of 2 and Cu 2+ in PBS buffer (ph = 7.0) solution in the range 0 2.5 µm (λ ex = 460 nm). The result of the analysis as follows: Linear Equation: Y = 9.4182 X+137.1364 R = 0.9808 S = 9.418 10 6 δ = ( F0 1 LOD = K δ / S = 1.148 10-6 M F 0 is the fluorescence intensity of 2. N 2 F0 ) = 3.6055 (N = 10) K = 3 S33
22. Job s plot for 2 with Cu 2+ in water solution. Figure S32. Job s plot for 2 with Cu 2+ in PBS buffer (ph = 7.0) solution. S34
23. Benesi-Hildebrand plots of 2 with Cu 2+ in water solution. Figure S33. Benesi-Hildebrand plot of 2, assuming 1:1 stoichiometry for association between 2 and Cu 2+ in PBS buffer (ph = 7.0) solution. The binding constant was determined using a reported procedure for a 1:1 binding mode. The result of the analysis as follows: Equation: Y = A +B X Y = 6.604 1.295 X R = 0.9916 F F lg F F max = lg K + lg[cu min 2+ K =4.01 10 6 M -1 ] S35
24. Fluorescence spectral changes of 2 with various ions in water solution. Figure S34. Fluorescence spectral changes of 2 (25.0 µm) with various cations (125.0 µm) in PBS buffer (ph = 7.0) solution (λ ex = 460 nm). S36
Figure S35. Fluorescence spectral changes of 2 (25.0 µm) with various anions (125.0 µm) in PBS buffer (ph = 7.0) solution (λ ex = 460 nm). S37
25. Plots of fluorescence intensity against time for 2 upon addition of Cu 2+. Figure S36. Plots of fluorescence intensity against time for 2 upon addition of 1.0 equiv of molar ratio of Cu 2+ in PBS buffer (ph = 7.0) solution. S38
26. The changes of UV-vis spectra of 2 upon addition of various cations in water solution. Figure S37. UV-vis spectra of 2 (25.0 µm) upon the addition of various cations (125.0 µm) in PBS buffer (ph = 7.0) solution. S39
Figure S38. UV-vis spectra of 2 (25.0 µm) upon the addition of Cu 2+ in PBS buffer (ph = 7.0) solution. S40
27. ORTEP plot of 1. Figure S39. ORTEP plot of 1 with thermal ellipsoids at 50% probability. S41
28. Optimized structures, cartesian coordinates and computed total energies of 1, 2, 2 Cu 2+ and [2 Cu 2+ ]. Figure S40. Optimized structure of 1. B3LYP/6-31G * in gas phase, E = -1937.87315290 a. u. Charge = 0 Multiplicity = 1 C -2.640565-2.574567 0.213172 C -3.524355-1.522939-0.152377 C -2.939262-0.281597-0.497787 C -1.560936-0.097125-0.484595 C -0.669328-1.154005-0.128447 C -1.274721-2.384969 0.219561 N -4.888927-1.705310-0.175607 C -5.799607-0.679205-0.681337 C -5.511224-2.947151 0.287127 C -5.627988-4.023752-0.798821 C -6.255820 0.324640 0.385168 O -1.018000 1.093964-0.848644 C 0.745181-0.898334-0.171166 C 1.833209-1.655756 0.185766 C 3.204567-1.168975 0.029842 Si -1.349159 2.741403-0.589799 C 0.003329 3.571439-1.599496 C -3.033326 3.220800-1.305653 C -1.227181 3.151520 1.277124 C -1.339947 4.683154 1.456358 C -2.361812 2.471947 2.074924 C 0.131585 2.675077 1.834772 S42
N 4.247611-1.826528 0.437857 C 5.420076-1.144900 0.176962 C 5.268290 0.106076-0.471121 S 3.563968 0.405570-0.758045 C 6.705663-1.599725 0.506550 C 7.803346-0.809050 0.187526 C 7.638276 0.429188-0.455885 C 6.369912 0.899969-0.791931 C 1.727666-2.966037 0.753666 N 1.619586-4.030617 1.213205 H -3.023081-3.554860 0.466532 H -3.554205 0.561172-0.779058 H -0.646967-3.224363 0.490220 H -6.672500-1.193874-1.098622 H -5.329140-0.161277-1.523016 H -6.508709-2.690277 0.661270 H -4.957725-3.328149 1.150465 H -6.123201-4.916317-0.399325 H -4.642432-4.316145-1.174129 H -6.217189-3.660791-1.648432 H -6.942302 1.060069-0.050489 H -5.403903 0.859873 0.816398 H -6.779036-0.183471 1.202858 H 0.979287 0.088709-0.558957 H -0.065072 4.664170-1.549085 H 1.001896 3.279005-1.257416 H -0.082124 3.281288-2.653071 H -3.881624 2.863541-0.711977 H -3.142562 2.828298-2.323573 H -3.117009 4.313097-1.366857 H -1.280582 4.943476 2.522778 H -0.530710 5.220515 0.947320 H -2.293460 5.075837 1.080956 H -2.275705 2.723161 3.141805 H -2.327833 1.379901 1.992336 H -3.353426 2.804933 1.743915 H 0.977265 3.143898 1.317628 H 0.249181 1.588907 1.750785 H 0.216685 2.933624 2.899816 H 6.816030-2.558122 1.003731 H 8.803216-1.151856 0.438385 H 8.510287 1.030914-0.696501 H 6.247328 1.857479-1.289223 S43
Figure S41. Optimized structure of 2. B3LYP/6-31G(d) in gas phase, E = -1411.2470209 a. u. Charge = 0 Multiplicity = 1 C 3.423985-1.582912-0.201083 C 3.959462-0.269558-0.038411 C 3.044882 0.800933 0.092988 C 1.677755 0.565029 0.067405 C 1.144206-0.730613-0.094620 C 2.060512-1.792313-0.228328 N 5.319267-0.053007-0.007326 C 6.281727-1.119164-0.283951 C 5.883340 1.264707 0.288281 C 6.055814 2.158001-0.946492 C 6.686739-1.927868 0.954949 O 0.865649 1.640763 0.195245 C -0.271263-0.864401-0.109218 C -1.111373 0.209087 0.021323 C -2.559396 0.038949 0.006288 C -0.534693 1.568955 0.180004 C -4.878384-0.854114-0.083788 C -4.732701 0.545989 0.067303 C -6.137747-1.452174-0.145991 C -7.260012-0.630760-0.054567 C -7.128683 0.760116 0.096041 C -5.874482 1.355713 0.157655 N -1.105169 2.691967 0.306798 H 4.083231-2.437169-0.284224 H 3.369187 1.827664 0.194776 H 1.678006-2.803333-0.347311 H 5.879580-1.777738-1.060170 H 7.169591-0.649787-0.722444 S44
H 6.856456 1.101791 0.765323 H 5.261066 1.761048 1.039314 H 6.496181 3.120474-0.661601 H 5.095582 2.351217-1.434471 H 6.718091 1.687004-1.681671 H 7.423095-2.694367 0.686507 H 7.134919-1.279503 1.716071 H 5.821676-2.424216 1.405870 H -0.681646-1.864896-0.230200 H -6.244235-2.526450-0.262117 H -8.250071-1.075542-0.100607 H -8.020010 1.377144 0.164920 H -5.757174 2.428552 0.273299 H -2.117903 2.557202 0.287279 N -3.430020 1.001874 0.112823 S -3.294218-1.597040-0.166956 S45
Figure S42. Optimized structure of 2 Cu 2+ complex. B3LYP/6-311++G ** in gas phase, E = -3051.584308 a. u. Charge = 2 Multiplicity = 2 C -3.859007-1.755755 0.101219 C -4.363809-0.406310 0.033173 C -3.416506 0.662808-0.034616 C -2.082044 0.374715-0.027885 C -1.576484-0.945359 0.040720 C -2.521522-2.006053 0.100969 N -5.682682-0.163476 0.031250 C -6.697694-1.230774 0.187856 C -6.243956 1.196343-0.125303 C -6.427349 1.916621 1.213368 C -7.135507-1.828557-1.151673 O -1.203828 1.413331-0.084711 C -0.189708-1.126490 0.049139 C 0.722297-0.078849-0.006328 C 2.144525-0.388454 0.023120 C 0.152514 1.281796-0.091200 C 4.324915-1.567561 0.131323 C 4.388915-0.158483 0.000020 C 5.475717-2.346551 0.202794 C 6.694515-1.691861 0.139917 C 6.773628-0.288027 0.008203 C 5.636188 0.483814-0.062188 N 0.804089 2.385709-0.172564 H -4.544531-2.585666 0.134235 H -3.723619 1.694590-0.069922 H -2.164254-3.025971 0.144494 H -6.314429-1.991499 0.861945 S46
H -7.545383-0.766048 0.688149 H -7.205789 1.070577-0.618795 H -5.614507 1.764339-0.805208 H -6.887671 2.886518 1.028542 H -5.476442 2.078642 1.719844 H -7.081687 1.357926 1.881302 H -7.915949-2.565859-0.967016 H -7.544706-1.067649-1.815173 H -6.310023-2.323564-1.662041 H 0.172297-2.144087 0.102300 H 5.426517-3.420978 0.303049 H 7.607629-2.268218 0.192406 H 7.745510 0.182238-0.037482 H 5.695181 1.559335-0.163462 H 0.188284 3.193737-0.220339 N 3.164702 0.457932-0.055007 S 2.666834-2.070291 0.181979 Cu 2.746701 2.374015-0.205252 S47
Figure S43. Optimized structure of [2 Cu 2+ ] complex. B3LYP/6-31++G ** in gas phase, E = -3051.1706003 a. u. Charge = 2 Multiplicity = 2 C 3.830087-1.828268 0.240260 C 4.357461-0.493809 0.073684 C 3.427157 0.586834-0.074602 C 2.083246 0.318613-0.052402 C 1.552433-0.987567 0.112238 C 2.481781-2.056486 0.256152 O 1.224376 1.377430-0.194658 C -0.128775 1.257691-0.207072 C -0.712275-0.063585 0.047091 C 0.153127-1.142116 0.156098 C -2.147837-0.339783 0.096492 N -0.782807 2.340492-0.486939 S -3.408407 0.766308 0.797665 C -4.637308-0.432258 0.397847 C -3.991886-1.579031-0.142392 N -2.628533-1.484376-0.283052 C -6.008004-0.388941 0.615023 C -6.745634-1.521518 0.256289 C -6.127569-2.664194-0.289601 C -4.756753-2.706917-0.492775 N 5.686752-0.272187 0.055059 C 6.271790 1.064211-0.201877 C 6.683231-1.344316 0.293791 C 6.474199 1.874579 1.086348 C 7.095195-2.063400-0.998418 H 4.501409-2.667890 0.335582 H 3.750731 1.610585-0.184201 S48
H 2.105829-3.065676 0.376195 H -0.272828-2.127998 0.298143 H -0.162145 3.129321-0.657886 H -6.497243 0.477950 1.040696 H -7.819037-1.516445 0.403673 H -6.736534-3.520700-0.551012 H -4.265551-3.578221-0.907372 H 7.231098 0.886180-0.689823 H 5.647208 1.595858-0.918548 H 7.548121-0.856161 0.744948 H 6.290790-2.039047 1.034716 H 6.948701 2.824584 0.832378 H 5.526407 2.085443 1.585895 H 7.125650 1.352408 1.789588 H 7.864279-2.800277-0.758363 H 6.253029-2.583316-1.459451 H 7.513728-1.367591-1.728182 Cu -2.712553 2.477748-0.476582 Reference Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.;Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.;Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.;Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A. Gaussian 03, revision E.01; Gaussian, Inc.: Wallingford, CT, 2004. S49
29. HOMO-LUMO energy levels and the molecular orbital plots of [2 Cu 2+ ]. Figure S44. HOMO-LUMO energy levels and the molecular orbital plots of [2 Cu 2+ ]. S50