References and Notes
For reviews, see:
1a
Rubart M.
Circ. Res.
2004,
95:
1154
1b
Heikal AA.
Webb WW.
Proc. SPIE - Int. Soc. Opt. Eng.
2002,
4812:
1 ; Nonlinear Spectroscopy
1c
So PTC.
Dong CY.
Masters BR.
Berland KM.
Annu. Rev. Biomed. Eng.
2000,
2:
399
1d
Potter SM.
Curr. Biol.
1996,
6:
1595
2a
Xu C.
Zipfel W.
Shear JB.
Williams RM.
Webb WW.
Proc. Natl. Acad. Sci. U.S.A.
1996,
93:
10763
2b
Xu C. In
Confocal and Two-Photon Microscopy
Diaspro A.
Wiley-Liss;
New York:
2002.
p.75-99
3a
Ohulchanskyy TY.
Pudavar HE.
Yarmoluk SM.
Yashchuk VM.
Bergey EJ.
Prasad PN.
Photochem. Photobiol.
2003,
77:
138
3b
Meltola NJ.
Wahlroos R.
Soini AE.
J. Fluoresc.
2004,
14:
635
3c
Meltola NJ.
Soini AE.
Hanninen PE.
J. Fluoresc.
2004,
14:
129
For example, see:
4a
Belfield KD.
Morales AR.
Kang B.-S.
Hales JM.
Hagan DJ.
Van Stryland EW.
Chapela VM.
Percino J.
Chem. Mater.
2004,
16:
4634
4b
Belfield KD.
Morales AR.
Hales JM.
Hagan DJ.
Van Stryland EW.
Chapela VM.
Percino J.
Chem. Mater.
2004,
16:
2267
4c
Rumi M.
Ehrlich JE.
Heikal AA.
Perry JW.
Barlow S.
Hu Z.
McCord-Maughon D.
Parker TC.
Rockel H.
Thayumanavan S.
Marder SR.
Beljonne D.
Bredas J.-L.
J. Am. Chem. Soc.
2000,
122:
9500
4d
Albota M.
Beljonne D.
Bredas J.-L.
Ehrlich JE.
Fu J.-Y.
Heikal AA.
Hess SE.
Kogej T.
Levin MD.
Marder SR.
McCord-Maughon D.
Perry JW.
Rockel H.
Rumi M.
Subramaniam G.
Webb WW.
Wu X.-L.
Xu C.
Science
1998,
281:
1653
4e
Reinhardt BA.
Brott LL.
Clarson SJ.
Dillard AG.
Bhatt JC.
Kannan R.
Yuan L.
He GS.
Prasad PN.
Chem. Mater.
1998,
10:
1863
4f
Abbotto A.
Beverina L.
Bozio R.
Facchetti A.
Ferrante C.
Pagani GA.
Pedron D.
Signorini R.
Org. Lett.
2002,
4:
1495
For reviews see:
5a
Esfand R.
Tomalia DA.
Drug Discov. Today
2001,
6:
427
5b
Boas U.
Heegaard PMH.
Chem. Soc. Rev.
2004,
33:
43
For examples, see:
6a
Day PN.
Nguyen KA.
Pachter R.
J. Phys. Chem. B
2005,
109:
1803
6b
Drobizhev M.
Karotki A.
Dzenis Y.
Rebane A.
Suo Z.
Spangler CW.
J. Phys. Chem. B
2003,
107:
7540
6c
Antonov L.
Kamada K.
Ohta K.
Kamounah FS.
Phys. Chem. Chem. Phys.
2003,
5:
1193
6d
Das GP.
Yeates AT.
Dudis DS.
Chem. Phys. Lett.
2002,
361:
71
6e
Wang X.
Wang D.
Zhou GY.
Yu W.
Zhou Y.
Fang Q.
Jiang M.
J. Mater. Chem.
2001,
11:
1600
7 Prepared according to a literature procedure, see: Calvin M.
Buckles RE.
J. Am. Chem. Soc.
1948,
62:
3324
8a
Kim Y.-W.
Jin J.-L.
Jin MY.
Choi K.-Y.
Kim J.-J.
Zyung T.
Polymer
1997,
38:
2269
8b
Tsubokawa N.
Satoh T.
Murota M.
Sato S.
Shimizu H.
Polym. Adv. Technol.
2001,
12:
596
9
Experimental Procedure.
1H NMR spectra were recorded on a Varian Mercury-300 NMR (300 MHz) spectrometer using TMS as the internal standard. Chemical shifts (δ) are reported in parts per million (ppm). Elemental analyses were performed by Atlantic Microlab, Inc. Norcross, GA. UV/visible spectra were recorded on an Agilent 8453 spectrophotometer using standard 1 cm path length cuvettes. Steady-state and fluorescence excitation anisotropy measurements were performed on a PTI Quantamaster spectrofluorometer. Fluorescence quantum yields were determined relative to 9,10-diphenylanthracone in cyclohexane.
Preparation of 3,3′,3′′,3′′′-[(
E
)-Ethene-1,2-diylbis(4,1-phenylenenitrilo)]tetrapropionic Acid Tetraethyl Ester (
4).
A mixture of 4,4′-diaminostilbene (6.3 g, 0.03 mol), freshly distilled ethyl acrylate (30 mL, 0.27 mol), and AcOH (4.5 mL) was refluxed for 48 h. The excess ethyl acrylate was removed under reduced pressure. The residue was purified by column chromatography using hexane-EtOAc (2:1) as eluent. Solvent removal and recrystallization from 95% EtOH afforded 7.2 g of pure product (39% yield). 1H NMR (300 MHz, CDCl3): δ = 7.35 (d, J = 7.8 Hz, 4 H, PhH), 6.82 (s, 2 H, CH=CH), 6.67 (d, J = 7.8 Hz, 4 H, PhH), 4.13 (q, J = 6.9 Hz, 8 H, OCH2), 3.67 (t, J = 7.1 Hz, 8 H, NCH2), 2.59 (t, J = 6.8 Hz, 8 H, C=OCH2), 1.26 (t, J = 7.2 Hz, 12 H, CH3). Anal. Calcd for C34H46N2O8 (610.74): C, 66.86; H, 7.59; N, 4.59. Found: C, 67.02; H, 7.62; N, 4.65.
Preparation of 3,3′,3′′,3′′′-[(
E
)-Ethene-1,2-diylbis(4,1-phenylenenitrilo)]tetrakis[
N
-(2-aminoethyl)]propan-amide (
1).
Diaminoethylene (6.67 g, 111 mmol) was added to a solution of 4 (0.61 g, 1.0 mmol) in MeOH (3.2 mL), and the mixture was reacted at r.t. under N2 for 60 h. The solvent and the remaining diaminoethylene were removed by distillation at 40 °C under reduced pressure. The yellow solid obtained was washed with Et2O and collected by suction filtration to afford 0.63 g of product (94% yield). NMR analysis indicated this product is a mixture of trans- and cis-isomers, which was recrystallized in EtOH-hexane for three times to give a pure trans-product; mp 180-181 °C. 1H NMR (300 MHz, D2O): δ = 7.25 (d, J = 5.1 Hz, 4 H, PhH), 6.76 (d, J = 3.9 Hz, 2 H, CH=CH), 6.64 (d, J = 5.4 Hz, 4 H, PhH), 3.46 (t, J = 3.5 Hz, 8 H, CH2), 2.95 (t, J = 3.6 Hz, 8 H, CH2), 2.40 (t, J = 3.6 Hz, 8 H, CH2), 2.29 (t, J = 3.8 Hz, 8 H, CH2). Anal. Calcd for C34H54N10O4·3H2O (720.90): C, 56.65; H, 8.40; N, 19.43. Found: C, 56.82; H, 8.25; N, 19.07.
10
Zhou G.
Wang X.
Wang D.
Shao Z.
Jiang M.
Appl. Opt.
2002,
41:
1120
11a The 2PA cross-sections measurement followed the procedure described in: Hernandez FE.
Belfield KD.
Cohanoschi I.
Chem. Phys. Lett.
2004,
391:
22
11b interestingly, two-photon cross-section of compound 1 is 3500 GM measured by picosecond laser sources, about one order of magnitude higher than that measured by femtosecond laser source. Similar phenomena have been reported in results from nanosecond laser sources by Prasad and co-workers; for examples, see:
11c
Chung S.
Kim K.
Lin T.
He GS.
Swiatkiewicz J.
Prasad PN.
J. Phys. Chem.
1999,
103:
10741
11d
Kim OK.
Lee K.-S.
Woo HY.
Kim K.-S.
He GS.
Swiatkiewicz J.
Prasad PN.
Chem. Mater.
2000,
12:
284
11e
He GS.
Lin T.-C.
Prasad PN.
Kannan R.
Vaia RA.
Tan L.-S.
J. Phys. Chem. B
2002,
106:
11081
11f More detailed experimental investigation is underway to understand the mechanism.
12 The sample preparation and multiphoton fluorescence imaging followed the procedure described in: Schafer-Hales KJ.
Belfield KD.
Yao S.
Frederiksen PK.
Hales JM.
Kolattukudy PE.
J. Biomed. Opt.
2005,
10:
051402