Supporting Information for Copper Complexes for Fluorescence-Based NO Detection in Aqueous Solution Mi Hee Lim and Stephen J. Lippard Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 RECEIVED DATE (will be automatically inserted after manuscript is accepted) Experimental Materials and Procedures All reagents were purchased from commercial suppliers and used as received unless stated otherwise. Acetonitrile (CH 3 CN), dichloromethane (CH 2 Cl 2 ), and tetrahydrofuran (THF) were purified by passage through alumina columns under an Ar atmosphere. The ligand Ds-en (5-Dimethylamino-N-(2- aminoethyl)-1-naphthalenesulfonamide) and copper complex [Cu(Ds-en) 2 ] were synthesized by previously reported methods. 1 Nitric oxide (NO) (Matheson 99%) was purified by a method adapted from the literature. 2 The NO gas was passed through an Ascarite (NaOH fused on silica gel) column and a 6 ft coil filled with silica gel cooled to -78 C. NO was transferred by a gastight syringe in the glove box. NO reactions were performed under anaerobic conditions. Fluorescence emission spectra were recorded at 25.0 ± 0.2 C or 37.0 ± 0.2 C on a Hitachi F- 3010 spectrophotometer. NMR spectra were recorded on a Varian 300 or 500 spectrometer and IR spectra were obtained on an Avatar 360 FTIR Instrument. Author to whom correspondence should be addressed. E-mail: lippard@mit.edu
S2 X-ray Crystallogaphy. A suitable crystal was mounted in Paratone N oil on the tip of a glass capillary and frozen under a 100 o C nitrogen cold stream. Data were collected on a Bruker APEX CCD X-ray diffractometer with Mo Kα radiation (λ = 0.71073 Å controlled by the SMART software package. 3 The general procedures used for data collection are reported elsewhere. 4 Empirical absorption corrections were calculated with the SADABS program. 5 Data were refined using the SAINTPLUS and SHELXTL software packages. 6,7 The structures were solved by the direct method. All non-hydrogen atoms were refined anisotropically. Hydrogen atoms were assigned idealized positions and given a thermal parameter of 1.2 times the thermal parameter of the atom to which it was attached. The structure solution was checked for higher symmetry with PLATON. 8 Electrochemistry. Cyclic voltammograms were recorded in an MBraun glovebox under N 2 with an EG&G model 263 potentiostat. A three-electrode setup was employed, consisting of an Ag/AgNO 3 reference electrode (0.01 M in CH 3 CN with 0.5 M (Bu 4 N)(PF 6 ), a platinum mesh auxiliary electrode, and a platinum disk working electrode. The supporting electrolyte was 0.5 M (Bu 4 N)(PF 6 ) in CH 3 CN. Cyclic voltammograms were externally referenced to the Cp 2 Fe/Cp 2 Fe + couple. EPR Spectroscopy. X-band EPR spectra were recorded on a Bruker EMX EPR spectrometer (9.37 GHz). Temperature control was performed with an Oxford Instruments ESR900 liquid-helium cryostat and ITC503 controller. Nitric oxide (1 equiv) was directly transferred by a gastight syringe into a 4 mm
S3 CH 2 Cl 2 /MeOH (1/4) solution of copper complexes in an EPR tube. The solution was then frozen at liquid N 2 and the sample measured at 50 K. 5-Dimethylamino-N-(2-pyridylmethyl)-1-naphthalenesulfonamide, (Ds- HAMP). A 0.55 g (5.0 mmol) portion of 2-(aminomethyl)pyridine was added to an aqueous solution of NaOH (0.20 g, 5.0 mmol, 5.0 ml). To this solution was added slowly over 15 min a THF (10 ml) solution of dansyl chloride (1.4 g, 5.0 mmol) with stirring. The resulting mixture was stirred for 4 h at room temperature and the THF solution was removed under reduced pressure. The yellow oil thus obtained was purified by column chromatography (SiO 2, 4:3 hexanes:ethyl acetate; R f = 0.22 by TLC), yielding a pale yellow product (1.2 g, 3.6 mmol, 73%); mp = 122-124 C. 1 H NMR (300 MHz, CDCl 3 )/δ(ppm): 2.87 (6H, s, 2CH 3 ), 4.23 (2H, d, -CH 2 -, J = 5.4), 6.27 (1H, m, naph-h), 7.03 (2H, d, naph-h, J = 7.5), 7.16 (1H, d, py-h, J = 7.5), 7.45 7.59 (3H, m, py-h & 2 naph-hs), 8.24 8.36 (3H, m, naph-h, SO 2 -NH-, & py-h), 8.47 (1H, d, py-h, J = 8.4). 13 C NMR (125 MHz, CDCl 3 )/δ(ppm): 154.9, 152.0, 149.0, 136.6, 134.7, 130.6, 130.0, 129.8, 129.8, 128.5, 123.2, 122.5, 121.9, 119.1, 115.4, 47.8, 45.6. FTIR (KBr, cm -1 ): 3071 (br, m), 2971 (w), 2939 (w), 2860 (w), 2826 (w), 2783 (w), 2660 (vw), 1615 (vw), 1591 (m), 1575 (m), 1502 (vw), 1479 (m), 1463 (m), 1451 (m), 1443 (m), 1403 (w), 1358 (vw), 1325 (vs), 1311 (m), 1294 (w), 1256 (vw), 1228 (w), 1199 (w), 1176 (vw), 1152 (s), 1143 (s),1105 (vw), 1094 (vw), 1074 (m), 1045 (w), 1005 (w), 976 (vw), 966 (vw), 943 (w), 927 (vw), 897 (w), 851 (m), 838 (w), 830 (w), 824 (w), 790 (s), 767 (m), 693 (w), 680 (w), 636 (s), 628 (s), 606 (m), 581 (vw), 569 (s), 537 (m), 516 (w), 499 (w), 483 (m), 444 (w), 405 (w). ESI(+)MS: Calcd MH +, 342.1; Found, 342.4.
S4 [Cu(Ds-AMP) 2 ] (2). To a CH 3 OH solution (5.0 ml) of Ds-HAMP (0.11 g, 0.31 mmol) was added a 0.1 M KOH solution (3.1 ml, 0.31 mmol). The solvent was evaporated under reduced pressure. The resulting residue was dissolved in CH 3 OH (10 ml) and copper acetate (32 mg, 0.16 mmol) was added. The solution was refluxed for 7 h and slowly cooled to room temperature. The blue microcrystalline powder (97 mg, 0.13 mmol, 81%) was collected and washed with cold CH 3 OH and Et 2 O; mp = 213 215 C. X-ray quality blue crystals were obtained by slow evaporation of CH 3 CN. FTIR (KBr, cm -1 ): 3068 (w), 2978 (w), 2933 (w), 2824 (w), 2824 (w), 2783 (w), 1608 (m), 1589 (m), 1570 (m), 1502 (w), 1474 (m), 1456 (m), 1439 (m), 1425 (m), 1408 (m), 1392 (m), 1357 (w), 1329 (w), 1281 (vs), 1271 (vs), 1229 (m), 1206 (w), 1197 (w), 1186 (w), 1136 (m), 1112 (w), 1101 (w), 1091 (w), 1073 (w), 1060 (w), 1046 (m), 1028 (w), 1005 (w), 998 (w), 970 (vw), 945 (m), 908 (m), 897 (w), 887 (w), 861 (m), 834 (w), 825 (w), 815 (w), 800 (m), 780 (w), 764 (m), 735 (w), 716 (m), 687 (w), 655 (w), 632 (s), 603 (w), 578 (s), 559 (s), 536 (w), 515 (vw), 488 (m), 467 (vw), 457 (vw), 420 (w). Anal. Calcd. for CuC 36 H 36 S 2 O 4 N 6 0.5 H 2 O: C, 57.39; H, 4.95; N, 11.15. Found: C, 57.01; H, 4.70; N, 11.07.
S5 Table S1. Summary of X-ray Crystallographic Data [Cu(Ds-AMP) 2 ] Formula C 36 H 36 CoN 6 O 4 S 2 Formula Weight 744.40 Space Group P2 1 /c a, Å 7.6658(18) b, Å 16.540(4) c, Å 26.737(6) β, deg 91.558(5) V, Å 3 3388.9(14) Z 4 ρ calc, g/cm 3 1.459 T, ºC -100 µ(mo Kα), mm -1 0.818 θ limits, deg 1.45 25.09 total no. of data 24851 no. of unique data 6020 no. of params 478 R a 0.0693 wr 2 b 0.1308 max, min peaks, e/å 3 0.444, -0.510 a R = Σ F o - F c /Σ F o, b wr 2 = {Σ[w(F o2 -F c2 ) 2 ]/Σ[w(F o2 ) 2 ]} 1/2
S6 Figure Captions Figure S1. Cyclic voltammgrams of 1 (dot-dash line) and 2 (solid line) in CH 3 CN (4 mm) with 0.5 M (Bu 4 N)(PF 6 ) as supporting electrolyte and a scan rate of 50 mv/s. The oxidations above +0.5 V are due to the ligands. Figure S2. Fluorescence response of a 20-µM solution of 2 in CH 2 Cl 2 (dotted line) after addition of 100 equiv of NO (solid line). Figure S3. EPR spectra of a 4 mm solution of 2 in 4:1 CH 3 OH:CH 2 Cl 2 (dotted line) after addition of 1 equiv of NO (solid line). Figure S4. Fluorescence spectra of a 4:1 CH 3 OH:CH 2 Cl 2 solution of Ds-HAMP (40 µm) without (dotted line) and with [Cu(CH 3 CN) 4 ](BF 4 ) (20 µm) in the presence of triethylamine (40 µm) (solid line). Figure S5. IR spectra of 2 (top), 2 with 10 equiv of NO (middle), and 2 with one equiv of NOBF 4 (bottom) in KBr. Figure S6. 1 H NMR spectra (6.6 9.0 ppm) of Ds-HAMP (4 mm in 4:1 CH 3 OH:CD 2 Cl 2, top), a reaction solution of 2 (4 mm in 4:1 CH 3 OH:CD 2 Cl 2 ) with 10 equiv of NO (bottom), and the latter solution to which was added Ds-HAMP (0.6 mm, middle). Figure S7. Fluorescence spectra of 4:1 CH 3 OH:CH 2 Cl 2 solution of 2 (dot-dash line), 2 with NOBF 4 (solid line), and 2 with NO (dashed line).
Figure S1. Lim and Lippard. S7
S8 14 12 Fluorescence Intensity 10 8 6 4 2 0 450 500 550 600 650 Wavelength (nm) Figure S2. Lim and Lippard.
S9 2080 2600 3120 3640 4160 Magnetic Field (G) Figure S3. Lim and Lippard.
S10 180 Fluorescence Intensity 135 90 45 0 450 500 550 600 650 Wavelength (nm) Figure S4. Lim and Lippard.
Figure S5. Lim and Lippard. S11
S12 Figure S6. Lim and Lippard.
S13 40 35 Fluorescence Intensity 30 25 20 15 10 5 0 450 500 550 600 650 Wavelength (nm) Figure S7. Lim and Lippard.
S14 References (1) Prodi, L.; Bolletta, F.; Montalti, M.; Zaccheroni, N. Eur. J. Inorg. Chem. 1999, 455-460. (2) Lorkovic, I. M.; Ford, P. C. Inorg. Chem. 2000, 39, 632-633. (3) SMART: Software for the CCD Detector System, version 5.626; Bruker AXS: Madison, WI, 2000. (4) Kuzelka, J.; Mukhopadhyay, S.; Spingler, B.; Lippard, S. J. Inorg. Chem. 2004, 43, 1751-1761. (5) Sheldrick, G. M. SADABS: Area-Detector Absorption Correction; University of Göttingen: Göttingen, Germany, 2001. (6) SAINTPLUS: Software for the CCD Detector System, version 5.01; Bruker AXS: Madison, WI, 1998. (7) SHELXTL: Program Library for Structure Solution and Molecular Graphics, version 6.1; Bruker AXS: Madison, WI, 2001. (8) Spek, A. L. PLATON, A Multipurpose Crystallographic Tool; Utrecht University: Utrecht, The Netherlands, 2000.