, Robert Pal , David Parker,a* David G. Smith, A,b

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 20111ESIChemical Communications 2011Evidence for the optical signalling of changes in bicarbonate concentrationwithin the mitochondrial region of living cellsGa-Lai Law,a Benjamin S. Murraya, Robert Pala, David Parker,a* David G. Smith,aand Ka-Leung Wonga,ba) Department of Chemistry, Durham University, South Road, Durham, DH1 3LEb) Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, HongKong.1. Cell culture: methods and procedures and representative cell imagesshowing complex localization to the mitochondria2. Ligand and complex synthesis and characterization, including HPLCtraces for complexes of L1 , L2 and L33. Examples of spectral titrations and data fitting.4. Table of photophysical data for Tb and Eu complexes.

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 201121. Cell culture: methods and proceduresHuman lung carcinoma A549 cells were purchased from the American type CultureCollection (ATCC) (#CCL-185, ATCC, Manassas, VA, USA). Cells were cultured inHam’s F12K medium with L-glutamine and phenol red (N3520, Sigma, St. Louis,MO, USA) supplemented with 10% foetal bovine serum at 37 C and 5% CO2.Human cervical carcinoma (HeLa) cells were maintained in an RMPI 1640 mediumsupplemented with 10% fetal bovine serum (FBS), 1% penicillin and streptomycinat37 Cin 5% CO2.MCF-7 cells were purchasedfrom the American type CultureCollection (ATCC) (#HTB-22, ATCC, Manassas, VA, USA) and were cultured inDMEM medium with L-glutamine and phenol red, supplemented with 10% neo-natalcalf serum containing 1% streptomycin and penicillin. In general,cells were passagedevery 3-5 days, maintaining confluence at around 80% for the imaging experiments.To study the localization behaviour of the europium/terbium complexes, experimentswere carried using various microscopes. One setup involved use of aLeica SP5 multiphoton confocal microscope (upright configuration) equipped with a UV lamp, anargon laser and a femtosecond-pulsed Ti:Sapphire laser (Libra II, Coherent) in whichlight was focused on to coverslip-adherent cells using a 40x oil or63x waterimmersion objective. The second set up used a Zeiss 510 LSM (upright configuration)confocal microscope equipped with a femtosecond-pulsed Ti:Sapphire laser (Libra II,Coherent), argon laser, and a UV lamp and was focused on coverslip-adherent cellsusing a 63 x oil immersion objective.For the in-vitro emission spectra, a lambda scansystem was used with a long-pass filter (LP 450 nm) for monitoring terbium emissionand a band-pass filter (550 nm - 700 nm) to obtain the emission from europium.For the evaluation of the variation of lanthanide emission intensity with externalcarbon dioxide partial pressure, imaging of living cells under the microscope requiredthe maintenance of the cell culture under accurately controlled conditions oftemperature and carbon dioxide. The cells were placed in the Zeiss PM S CO2incubator. The temperature within the CO2 chamber enclosure were thermostaticallymaintained at37 Callowing the observed cells to be kept alive for days. In additionvariation of the percentage of carbon dioxide of the heated air was enabled using a

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 20113CO2controller. 10μM concentrations of lanthanide complexes were dosed in thegrowth medium of the cells and incubated for up to 6 hours in 5% CO2. The CO2content inside the incubator was adjusted from 5 to 4 to 3% and then back to 5%. Ineach case, the spectral emission data and microscopic images were taken 30 minutesafter varying the CO2 content to allow equilibration.ESI Figure 1Epifluorescence microscopy images showing the staining of MCF-7 cells with :left: Mitotracker Green; centre: [Eu.L2]3 using a 570 nm long pass filter; right :the co-localised image showing good correspondence.2. Ligand and complex synthesisSynthesis of ligands L2 and -azaxanthone(147mg,0.459mmol),chloroacetic acid 2,5-dioxo-pyrrolidin-1-yl ester (175 mg, 0.917 mmol) andtriethylamine were stirred in dry THF (20 ml) under argon for 18h at roomtemperature. DCM (20 ml) was added and the mixture was washed with H2O (3 x 20

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 20114ml). The solvent was removed under reduced pressure to leave the desired product asa light yellow powder (101 mg, 282 µmol, 61%).1H-NMR (CDCl3, 700 MHz) δ 8.99 (1H, d, J 2.1, H6), 8.70 (1H, d, J 7.9, H4),8.43 (1H, dd, J 8.7, 2.1, H8), 7.67 (1H, d, J 8.7, H9), 7.66 (1H, br s, H13), 7.45(1H, d, J 7.9, H3), 4.76 (2H, d, J 5.5, H12), 4.17 (2H, s, H15), 3.98 (3H, s, H11);13C-NMR (CDCl3, 175 MHz) δ 176.7 (C5), 166.5 (C14), 165.7 (C11), 162.4 (C2), 160.0(C1’), 158.3 (C9’), 138.6 (C4), 136.4 (C8), 129.3 (C6), 127.2 (C5’), 121.5 (C7), 119.9(C3), 119.1 (C9), 115.8 (C4’), 52.7 (C12), 45.0 (C10), 42.7 (C15); MS (ES ) m/z 361.1[M H] ; HRMS ( m/z): [M Na] calculated for C17H13ClNaN2O5 383.0419, found383.0411.(S)-Alanine ethyl ester hydrochloride(S)-Alanine (1.00 g, 11.2 mmol) was suspended in dry ethanol (40 ml). Dry HCl(produced by dropping conc. H2SO4 onto NaCl and passing through conc. H2SO4)was bubbled through the solution for 3 h, while refluxing under argon. The bubblingwas stopped and the mixture boiled under reflux for a further 12 h. The solvent wasremoved under reduced pressure to yield the product as a colourless solid (1.71 g,11.2 mmol, 99 %).m.p. 82 – 83 C; 1H-NMR (CD3OD, 400 MHz) δ 4.27 (q, 2H, J 6.8, H1), 4.02 (1H, q, J 7.2, H4), 1.53 (d, 3H, J 6.8, H2), 1.29 (t, 3H, J 7.2, H5);13C-NMR (CDCl3, 175 MHz) δ 170.0 (C3), 62.4 (C2), 49.3 (C4), 16.1 (C5), 14.0 (C1);ESI/MS m/z 118.2 [M H] ; HRMS ( m/z): [M H] calculated for C5H12O2N118.0863, found 118.0863.Bromoacetyl-(S)-alanine ethyl ester(S)-Alanine ethyl ester hydrochloride (1.71 g, 11.2 mmol) was stirred under argon at 20 C in dry CHCl3 (10 ml). Triethylamine (2.3 ml, 32.0 mmol) and bromoacetylbromide (1.6 ml, 17.9 mmol) were added and the mixture stirred at -20 C for 2 h

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 20115before being allowed to gradually warm to room temperature and stirred for a further12 h. The reaction was then halted and washed with aq. HCl (6 M, 30 ml) and thenH2O (4 x 25 ml). The organic phase was dried and the product recrystallised fromDCM / pet. ether as white crystals (1.88 g, 7.95 mmol, 71 %). mp 33 – 34 C; 1HNMR (CDCl3, 400 MHz) δ 7.03 (s, br, H6), 4.55 (m, H4), 4.23 (q, J 7.2, H2), 3.88 (s,2H, H8), 1.45 (d, 3H, J 7.0, H4), 1.28 (t, 3H, J 7.2, H1);13C-NMR (CDCl3, 125MHz) δ 172.5 (C7), 165.6 (C3), 62.1 (C2), 48.8 (C4), 42.3 (C8), 18.0 (C5), 14.0 (C1);ESI/MS m/z 260.1 [M Na] ; HRMS ( m/z): [M H] calculated for C7H12NO3BrNa259.9893, found yloxycarbonyl)-1,4,7,10-tetraazacyclododecane (0.738 g, 1.69 mmol)was dissolved in dry MeCN (30 ml) and bromoacetyl-(S)-alanine ethyl ester (0.834 g,3.52 mmol) was added. K2CO3 (1.3 g, 9.4 mmol) was added and the mixture stirredat 60 C under argon for 4 days.The reaction was allowed to cool to roomtemperature and filtered. Solvent was removed under reduced pressure. The desiredproduct was isolated by column chromatography on silica gel (DCM 3 % MeOH),as a light orange glassy oil (0.973 g, 1.35 mmol, 80 %).1H-NMR (CDCl3, 200 MHz) δ7.27 (m, 10H, H3), 5.05 (s, 4H, H2), 4.43 (s, br, 2H, H7), 4.09 (q, 4H, J 7.2, H10),2.76 – 3.47 (m, br, 16H, H12), 1.34 (m, br, 3H, H8), 1.21 (t, 6H, J 7.2, H11);13C-NMR (CDCl3, 125 MHz) δ 172.9 (C9), 170.9 (C5), 157.0 (C1), 136.7 (C3), 128.8 (C3),128.4 (C3), 67.6 (C10), 61.5 (C4), 55.9, 54.9 (C12), 48.1 (C7), 18.1 (C8), 14.4 (C10); MS(ES ) m/z 755.3 [M H] ; HRMS ( m/z): [M H] calculated for C38H55N6O10755.3973, found 4,7,10-tetraazacyclododecane

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry e (0.973 g, 1.35 mmol) was dissolved in MeOH (20 ml) andPd(OH)2/C (Pd content 10 %) (75 mg) added. The mixture was shaken in a Parrhydrogenator flask at 40 psi H2 for 3 days. The resulting mixture was filtered throughCelite leaving a clear solution which was evaporated and dried under reducedpressure to yield a yellow viscous oil (0.400 g, 0.823 mmol, 61 %).1H-NMR (CDCl3,400 MHz) δ 7.70 (2H, m, br, H10), 7.53 (2H, m, br, H3), 4.54 (2H, m, H4), 4.17 (4H,m, H7), 3.26 (4H, m, H1), 2.60-2.85 (16H, m, br, H9), 1.38 (6H, m, H8), 1.26 (6H, m,H7); MS (ES );13C-NMR (CDCl3, 125 MHz) δ 173.1 (C6), 171.0 (C2), 62.1 (C7),61.4 (C1), 53.4, 52.5 (C9), 48.2 (C4), 18.5 (C6), 14.4 (C8); MS (ES ) m/z 487.4 [M H] ; HRMS ( m/z): [M H] calculated for C22H43O6N6 487.3239 found, carboxylic cane (0.812 g, 1.67mmol) and di-tert-butyl dicarbonate (0.363 mg, 1.67 mmol) were stirred, under argon,in CHCl3 at 30 ºC for 18 h. Solvent was then removed under reduced pressure andthe product purified by column chromatography on silica gel (DCM 3 % MeOH)(239 mg, 0.407 mmol, 24%).

Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is The Royal Society of Chemistry 20117RF 0.23 (alumina, DCM : 8% MeOH); 1H-NMR (CDCl3, 700 MHz) δ 7.47 (2H, d,br, H3), 4.58 (2H, q, J 7.6, H4), 4.16 (4H, q, J 7.6, H7), 3.26 (4H, m, H1), 2.803.40 (16H, m, br, H9), 1.42 (9H, s, H11), 1.40 (6H, t, J 7.6, H5), 1.24 (6H, t, J 7.6,H8); 13C-NMR (CDCl3, 126 MHz) δ 173.2 (C6), 80.8 (C9), 61.9 (C7), 61.0 (C1), 55.3(C4), 52.1 (C9), 42.0 (C4), 30.8 (C10), 28.7 (C11), 27.0 (C5), 14.4 (C1), 14.0 (C8); MS(ES ) m/z 587.5 [M H] ; HRMS ( m/z): [M H] calculated for C27H51N6O8587.3758, found 587.3768.Tert-butyl is(ethyl-N-acetyl-S-alanine)-4-carboxylic acid tert-butyl carbonylaminomethyl-1-azaxanthone (16.8 mg, 46.6μmol) and DIPEA (40 μl, 0.230 mmol) in dry MeCN under argon. The mixture wasstirred at 60 C for 24 h.A further addition of l-1-azaxanthone (19.0 mg, 52.7 μmol) and DIPEA(50 μl, 0.287 mmol) was made at this time-point and the mixture stirred for a further18 h. Solvent was then removed under reduced pressure and the residue purified bycolumn chromatography (silica, DCM 7 % MeOH) to yield the product as a glassyorange solid (63.9 mg, 70.2 μmol, 71 %).1H-NMR (CDCl3, 500 MHz) δ 11.21 (8.96(1H, d, J 2.3, H6), 8.64 (1H, d, J 7.8, H4), 8.41 (1H, dd, J 8.9, 2.3, H8), 7.60(1H, d, J 8.9, H9), 7.43 (1H, d, J 7.8, H3), 4.71 (2H, d, J 4.8, H12), 4.50 (2H, p, J 6.8, H19), 4.12 (4H, q, J 7.0, H22), 3.96 (3H, s, H11), 3.55 - 2.60 (22H, br. m, H15,