reSeArCH Letter
PtTPTNP
Ru(bpy) (PF )
TTBP
9. Park, Y. I., Lee, K. T., Suh, Y. D. & Hyeon, T. Upconverting nanoparticles: a versatile
platform for wide-ꢁeld two-photon microscopy and multi-modal in vivo
imaging. Chem. Soc. Rev. 44, 1302–1317 (2015).
ꢀ
ꢁ ꢂ
3
2
2
1
1
0,000
5,000
0,000
5,000
0,000
1
0. Zhou, Y. et al. An upconverted photonic nonvolatile memory. Nat. Commun. 5,
720 (2014).
4
1
1. Viger, M. L., Grossman, M., Fomina, N. & Almutairi, A. Low power upconverted
near-IR light for eꢂcient polymeric nanoparticle degradation and cargo release.
Adv. Mater. 25, 3733–3738 (2013).
H = 15,376
H =10,965
1
2. He, S. et al. Ultralow-intensity near-infrared light induces drug delivery by
upconverting nanoparticles. Chem. Commun. 51, 431–434 (2015).
3. Chen, Z., Sun, W., Butt, H.-J. & Wu, S. Upconverting-nanoparticle-assisted
photochemistry induced by low-intensity near-infrared light: how low can we
go? Chem. Eur. J. 21, 9165–9170 (2015).
1
H = 2,100
5,000
14. Askes, S. H. C., Bahreman, A. & Bonnet, S. Activation of a photodissociative
ruthenium complex by triplet–triplet annihilation upconversion in liposomes.
Angew. Chem. Int. Ed. 53, 1029–1033 (2014).
15. Mahboub, M., Huang, Z. & Tang, M. L. Eꢂcient infrared-to-visible upconversion
with subsolar irradiance. Nano Lett. 16, 7169–7175 (2016).
0
4
00
450
500
550
600
650
700
750
Wavelength (nm)
1
6. Majek, M., Faltermeier, U., Dick, B., Pérez-Ruiz, R. & Jacobi von Wangelin, A.
Application of visible-to-UV photon upconversion to photoredox catalysis: the
activation of aryl bromides. Chem. Eur. J. 21, 15496–15501 (2015).
7. Häring, M., Pérez-Ruiz, R., Jacobi von Wangelin, A. & Díaz, D. D. Intragel
photoreduction of aryl halides by green-to-blue upconversion under aerobic
conditions. Chem. Commun. 51, 16848–16851 (2015).
Fig. 4 | Application of the Beer–Lambert law to blue and NIR
light. Comparison of extinction coefficients and concentrations of
1
Ru(bpy)3(PF6)2 and TTBP with those of PtTPTNP reveals a large increase
in reaction penetration by infrared light compared to blue light, according
to the Beer–Lambert relation A = εcl (A, absorbance; ε, molar extinction
18. Singh-Rachford, T. N. & Castellano, F. N. Low power visible-to-UV upconversion.
2
+
coefficient; c, concentration; l, path length). For [Ru(bpy)3] , ε is
J. Phys. Chem. A 113, 5912–5917 (2009).
9. Singh-Rachford, T. N. & Castellano, F. N. Photon upconversion based on
1
7
.29 times larger and c is 41.7 times larger than for PtTPTNP; infrared
sensitized triplet–triplet annihilation. Coord. Chem. Rev. 254, 2560–2573
light (730 nm) thus penetrates 304 times further than blue light (450 nm)
through the reaction solution in Fig. 2d. For TTBP, ε is 5.17 times
larger and c is 56.7 times larger than for PtTPTNP; the penetration of
infrared light (730 nm) is therefore 293 times greater than that of blue light
(
2010).
2
0. Hartnett, P. E. et al. Eꢃects of crystal morphology on singlet exciton ꢁssion in
diketopyrrolopyrrole thin ꢁlms. J. Phys. Chem. B 120, 1357–1366 (2016).
21. Singh-Rachford, T. N. & Castellano, F. N. Pd(II) phthalocyanine-sensitized
triplet–triplet annihilation from rubrene. J. Phys. Chem. A 112, 3550–3556
(
450 nm) through the reaction solution in Fig. 2f.
(2008).
2
2. Neumann, M., Füldner, S., König, B. & Zeitler, K. Metal-free, cooperative
asymmetric organophotoredox catalysis with visible light. Angew. Chem. Int. Ed.
both of these challenges. For example, the penetration of infrared light
5
0, 951–954 (2011).
through the [2+2] cyclization reaction mixture (Fig. 2d) is 304 times 23. Mashraqui, S. H. & Kellogg, R. M. 3-Methyl-2,3-dihydrobenzothiazoles as
reducing agent. Dye enhanced photoreactions. Tetrahedr. Lett. 26, 1453–1456
deeper than that of blue light, based on concentration and extinction
(1985).
coefficients (Fig. 4). By the same analysis, we found that infrared light
penetrates 293 times further than blue light through the polymeriza-
tion reaction mixture (Fig. 2f), thus rendering this chemistry scalable
2
4. Natarajan, P., Kumar, N. & Sharma, M. Visible light-mediated intramolecular
C–H arylation of diazonium salts of N-(2-aminoaryl)benzoimines: a facile
synthesis of 6-arylphenanthridines. Org. Chem. Front. 3, 1265–1270 (2016).
5. Sommer, J. R. et al. Photophysical properties of near-infrared phosphorescent
π-extended platinum porphyrins. Chem. Mater. 23, 5296–5304 (2011).
2
(
Fig. 3d). This reaction also demonstrates that a laser is not necessary to
perform upconversion, suggesting that this technique could be broadly 26. Deng, F., Sommer, J. R., Myahkostupov, M., Schanze, K. S. & Castellano, F. N.
Near-IR phosphorescent metalloporphyrin as a photochemical upconversion
sensitizer. Chem. Commun. 49, 7406–7408 (2013).
7. Sasaki, Y., Amemori, S., Kouno, H., Yanai, N. & Kimizuka, N. Near infrared-to-blue
photon upconversion by exploiting direct S–T absorption of a molecular
sensitizer. J. Mater. Chem. C 5, 5063–5067 (2017).
applied. Scalability and improved penetration through materials were
demonstrated by performing polymerization on a multi-gram scale
2
in an opaque silicone mould (Fig. 3e). The sealed mould is resistant
to visible light, while the NIR photons pass through uninhibited. As
predicted, the defined shapes were achieved only with the NIR lamp
and not with the blue lamp. With this proof-of-principle experiment
2
8. Ischay, M. A., Anzovino, M. E., Du, J. & Yoon, T. P. Eꢂcient visible light
photocatalysis of [2+2] enone cycloadditions. J. Am. Chem. Soc. 130,
12886–12887 (2008).
it is possible to observe the effects of the penetration of infrared radia- 29. Miyake, G. M. & Theriot, J. C. Perylene as an organic photocatalyst for the
radical polymerization of functionalized vinyl monomers through oxidative
tion through various barriers, and studies to characterize the materials
quenching with alkyl bromides and visible light. Macromolecules 47,
properties of various gels will follow.
8
255–8261 (2014).
3
0. Tucker, J. W., Zhang, Y., Jamison, T. F. & Stephenson, C. R. J. Visible-light
photoredox catalysis in ꢀow. Angew. Chem. Int. Ed. 51, 4144–4147 (2012).
Data availability
The data that support the findings of this study are available from the correspond-
ing authors on reasonable request.
Acknowledgements L.M.C. thanks the National Science Foundation (NSF
CAREER DMR-1351293) for funding. A.B.P. thanks the NSF Graduate Research
Fellowship Program (DGE-16-44869). D.N.C. is supported by the Rowland
Fellowship at the Rowland Institute at Harvard. T.R. thanks the National
Institute of General Medical Sciences (GM125206).
Received: 11 July 2018;Accepted: 20 November 2018;
Published online 16 January 2019.
1
.
Prier, C. K., Rankic, D. A. & MacMillan, D. W. C. Visible light photoredox catalysis
with transition metal complexes: applications in organic synthesis. Chem. Rev.
Author contributions A.B.P. and D.N.C. carried out the upconversion
experiments. B.D.R., A.B.P. and E.M.C. performed and analysed the photoredox
and materials penetration experiments. D.N.C., T.R. and L.M.C. initiated and
directed the study, and wrote the manuscript with contributions from all
authors.
1
13, 5322–5363 (2013).
Romero, N. A. & Nicewicz, D. A. Organic photoredox catalysis. Chem. Rev. 116,
0075–10166 (2016).
2
.
.
1
3
Cambié, D., Bottecchia, C., Straathof, N. J. W., Hessel, V. & Noël, T. Applications of
continuous-ꢀow photochemistry in organic synthesis, material science, and
water treatment. Chem. Rev. 116, 10276–10341 (2016).
Smith, A. M., Mancini, M. C. & Nie, S. Bioimaging: second window for in vivo
imaging. Nat. Nanotechnol. 4, 710–711 (2009).
Competing interests A provisional patent has been filed on this technology by
the institutions on behalf of the authors of this work (US Provisional Application
62/641,739).
4.
5
.
Arias-Rotondo, D. M. & McCusker, J. K. The photophysics of photoredox catalysis:
a roadmap for catalyst design. Chem. Soc. Rev. 45, 5803–5820 (2016).
Le, C. C. et al. A general small-scale reactor to enable standardization and
acceleration of photocatalytic reactions. ACS Cent. Sci. 3, 647–653 (2017).
Zhou, J., Liu, Q., Feng, W., Sun, Y. & Li, F. Upconversion luminescent materials:
advances and applications. Chem. Rev. 115, 395–465 (2015).
Additional information
Correspondence and requests for materials should be addressed to D.N.C., T.R.
or L.M.C.
6.
7.
8.
Schulze, T. F. & Schmidt, T. W. Photochemical upconversion: present status and
prospects for its application to solar energy conversion. Energy Environ. Sci. 8,
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional
claims in published maps and institutional affiliations.
103–125 (2015).
3
4 6 | N A t U r e | V O L 5 6 5 | 1 7 J A N U A r Y 2 0 1 9
©
2019 Springer Nature Limited. All rights reserved.