Handbook on the Physics and Chemistry of Rare Earths Vol. 37 edited by K.A. Gschneidner, Jr., J.-C.G. Bünzli and V.K. Pecharsky © 2007 Elsevier B.V. All rights reserved. ISSN: 0168-1273/DOI: 10.1016/S0168-1273(07)37035-9 Chapter 235 LANTHANIDE NEAR-INFRARED LUMINESCENCE IN MOLECULAR PROBES AND DEVICES Steve COMBY and Jean-Claude G. BÜNZLI École Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Lanthanide Supramolecular Chemistry, BCH 1402, CH-1015 Lausanne, Switzerland E-mail: jean-claude.bunzli@epfl.ch Contents List of abbreviations 218 3.2.1.1. Chemiluminescence (CL) 306 1. Outline and scope of the review 221 3.2.1.2. Electroluminescence 307 2. Photophysics of near-infrared emitting triva- 3.2.1.3. Pyrazolones 307 lent lanthanide ions 224 3.2.2. Quinolinates 307 2.1. Near-infrared transitions 224 3.2.3. Terphenyl-based ligands 313 2.2. Sensitization processes 227 3.2.4. Polyaminocarboxylates 321 2.3. Erbium sensitization by ytterbium and/or 3.2.5. Other chelating agents 329 cerium 231 3.2.5.1. Dyes 329 2.4. The special case of ytterbium 232 3.2.5.2. Carboxylates 331 2.5. Quantum yields and radiative lifetimes 234 3.2.5.3. Tropolonates 334 2.6. Multi-photon absorption and up-conversion 240 3.2.5.4. Imidophosphinates 336 2.7. Synthetic strategies for ligand and com- 3.2.5.5. Pyrazoylborates 337 plex design 241 3.2.6. New synthetic strategies podands, 2.7.1. Linear polydentate and multifunc- dendrimers, self-assembly processes 339 tional ligands 242 3.2.6.1. Podands 339 2.7.2. Macrocyclic receptors (Sastri et al., 2003) 243 3.2.6.2. Dendrimers 343 2.7.3. Podands 243 3.2.6.3. Self-assembly processes 348 2.7.4. Self-assembly processes 244 3.3. Heterometallic functional assemblies: 3. NIR-emitting molecular edifices 244 taking advantage of d-transition metal 3.1. Macrocyclic ligands 244 ions 349 II 3.1.1. Simple lanthanide porphyrinates 244 3.3.1. Zn as structure stabilizer 351 3.1.2. Other lanthanide porphyrinates 256 3.3.2. Transition metal ions as modi- 3.1.3. Derivatized coronands and cryp- fiers of ligand electronic properties tands 259 and/or recognition units 354 3.1.4. Derivatized cyclens 268 3.3.3. d-Transition metal ions as lumines- 3.1.5. Derivatized calixarenes and resor- cence sensitizers 357 cinarenes 280 3.3.4. d-Transition metal ions for extend- 3.2. Acyclic ligands 287 ing the apparent LnIII lifetime 366 3.2.1. Beta-diketonates and related che- 3.3.5. 4f-Transition metal ions as lumi- lates 287 nescence sensitizers 369 217 218 S. COMBY and J.-C.G. BÜNZLI 3.4. NIR luminescence in extended structures 4.2. Optical fiber amplifiers and waveguides 404 and various materials 371 4.2.1. Neodymium-doped polymers 409 3.4.1. Coordination polymers 371 4.2.2. Erbium-doped polymers 411 3.4.2. Inorganic clusters 376 4.3. NIR organic light-emitting diodes 3.4.3. Zeolites and composite mesopo- (OLEDs) 412 rous materials (inorganic–organic 4.3.1. Neodymium OLEDs 414 hybrids) 380 4.3.2. Erbium OLEDs 416 3.4.3.1. Zeolites 380 4.3.3. Ytterbium OLEDs 417 3.4.3.2. Simple silica matrices 382 4.3.4. OLEDs with other lanthanide ions 419 3.4.3.3. Xerogels: ureasilicates 4.4. Analytical applications 420 and urethanesilicates 385 4.5. Biomedical applications 422 3.4.3.4. Covalently-linked lumi- 5. Comparison of the chromophores 425 nescent hybrid materials 387 5.1. Note on quantum yields 425 3.4.4. Microspheres and nanoparticles 390 6. Conclusions 453 3.4.5. Fullerenes 395 3.4.6. Ionic liquids and liquid crystal 6.1. Is sensitization of the NIR luminescence a phases 396 problem? 454 4. Overview of potential applications 400 6.2. Preventing nonradiative deactivation: the 4.1. Inorganic liquid lasers 400 real problem 454 4.1.1. Neodymium in selenium oxychlo- 6.3. Best complexation agents and chromo- ride 400 phores 455 III 4.1.2. Neodymium in phosphorus oxy- 6.4. The future of NIR-emitting Ln ions in chloride 402 applications 455 4.1.3. Other lasing ions 403 6.5. Concluding statement 456 4.1.4. A second try 404 References 457 List of abbreviations 8-Q 8-hydroxyquinolinate CD circular dichroism aad adamantylideneadamantane-1,2- CL chemiluminescence dioxetane CN coordination number ac acetate CoP (cyclopentadienyl)tris(diethyl- acac acetylacetonate phosphito)cobaltate(I) AMP amplifying waveguide spiral anion ba benzoylacetonate CPL circularly polarized luminescence bath monobathophenantholine CSA cationic surfactant BCP bathocuproine cw continuous wave bdc 1,4-benzenedicarboxylate cyclam 1,4,8,11-tetraazacyclotetradecane bdc-F4 2,3,5,6-tetrafluoro-1,4-benzene- cyclen 1,4,7,10-tetraaza-dodecane dicarboxylate dam diantipyrylmethanate bppz 2,3-bis-(2-pyridyl)pyrazine daphm diantipyrylphenylmethanate bptz 3,6-bis-(2-pyridyl)tetrazine dapm diantipyrylpropylmethanate bpy 2,2 -bipyridine dbm dibenzoylmethanate bpym 2,2 -bipyrimidine DEDMS diethoxydimethylsilane bpypz 3,5-di(2-pyridyl)pyrazolate DEMS diethoxymethylsilane BSA bovine serum albumin dithi 2-dithienyl-2,2 -bipyridazine btfa benzoyltrifluoroacetonate dme 1,2-dimethoxy-ethane LANTHANIDE NEAR-INFRARED LUMINESCENCE IN MOLECULAR PROBES AND DEVICES 219 dmf dimethylformamide HBS HEPES-buffered saline buffer dmp dipivaloylmethanate hCG human chorionic gonadotropin dmso dimethylsulfoxide HEPES N-(2-hydroxyethyl)-piperazine- DNA deoxyribonucleic acid N -2-ethanesulfonic acid dnm dinaphthoylmethanate hesa hexylsalicylate do3a 1,4,7,10-tetraaza-cyclododecane- hfa hexafluoroacetylacetonate N,N ,N -triacetate HOMO highest occupied molecular dota 1,4,7,10-tetraaza-cyclododecane- orbital N,N ,N ,N -tetraacetate HPLC high performance liquid dotma 1R,4R,7R,10R-α,α ,α ,α - chromatography tetramethyl-1,4,7,10-tetraaza- HSA human serum albumin cyclododecane-1,4,7,10-tetra- HSAB hard and soft acid and base acetate theory dotp 1,4,7,10-tetraazacyclododecane- IgG immunoglobulin G 1,4,7,10-tetrakis-methylene- im imidazole phosphonate ITO indium tin oxide dpa pyridine-2,6-dicarboxylate IUPAC Internationl Union of Pure and (dipicolinate) Applied Chemistry dpga diphenylguanidine LB Langmuir–Blodgett dpm dipivaloylmethanate LCD liquid crystal display dppm bis(diphenylphosphinomethane) LD laser diode dtpa diethylenetrinitrilopentaacetate LED light emitting diode dtta diethylenetriaminetetraacetate LF ligand field ECL electrochemically generated LLCT ligand-to-ligand charge transfer luminescence state edta ethylenediamine-N,N ,N ,N - LMCT ligand-to-metal charge transfer tetraacetate state ELISA enzyme-linked immunosorbent LUMO lowest unoccupied molecular assay orbital ESA excited state absorption MBBA N-(p-methoxybenzylidene)-p- ET electron transfer butylaniline Etonium 1,2-ethanediaminium, MCD magnetic circular dichroism N,N -bis[2-(decyloxy)-2-oxo- MDMO-PPV polyl[2-methoxy-5-(3 ,7 -di- ethyl]-N,N,N ,N -tetramethyl- methyl-octyloxy)]-p-phenylene dichloride vinylene ETU energy transfer up-conversion mgl 1-deoxy-1-(methylamino)glucitol fac facial MLCT metal-to-ligand charge transfer FAU Faujasite state fod 6,6,7,7,8,8,8-heptafluoro-2,2-di- MMA methylmethacrylate methyl-3,5-octadionate MOF metal–organic framework fwhh full width at half height (coordination polymer) fx fluorexon MRI magnetic resonance imaging had hexaaza-triphenylene NASI N-acryloxysuccinimide 220 S. COMBY and J.-C.G. BÜNZLI NIR near infrared Quin 2-methyl-8-hydroxyquinolinate NIT2py 4,4,5,5-tetramethyl-2-(2 - RTIL room temperature ionic liquid pyridyl)-4,5-dihydro-1H - SAP square antiprism imidazol-1-oxyl 3-oxide SHE standard hydrogen electrode NMR nuclear magnetic resonance SOMO single occupied molecular orbital nta nitrilotriacetate stta mono-thio-thenoyltrifluoro- NTA 4,4,4-trifluoro-1-(2-naphthyl)- acetonate 1,3-butanedionate tbo trimethylenebis(oxamide) OEP octaethylporphyrinate TBP tetrabenzoporphyrinate OLED organic light emitting TEOS tetraethyl orthosilicate diode Tf2N bis(trifluoromethanesulfonyl)- Otf trifluoromethanesulfonate imide or ox oxalate bis(perfluoromethylsulfonyl)- PAN 1-(2-pyridylazo)-2-naphthol aminate (pms) PAR 1-(2-pyridylazo)resorcinol TGA thermogravimetric analysis pbs bis(perfluorobutylsulfonyl)imide, thf tetrahydrofuran [C4F9SO2]2N TMA tetramethylammonium Pc phthalocyanine TMOS tetramethoxysilane pdon 1,10-phenanthroline-5,6-dione topo trioctylphosphine oxide PEDOT poly(3,4-ethylene Tos tosylate dioxythiophene) TpH hydridotris(1-pyrazolyl)borate PEG polyethyleneglycol TPD N,N-diphenyl-N,N-bis(3- PET photoinduced electron transfer methylphenyl)-[1,1 -biphenyl]- phen 1,10-phenanthroline 4,4 -diamine PMMA polymethylmethacrylate tpen tetrakis(2-pyridylmethyl)- pms bis(perfluoromethylsulfonyl)- ethylenediamine aminate or TPP tetraphenylporphyrinate bis(trifluoromethanesulfonyl)- tppo triphenylphosphine oxide imide (Tf2N) tpy 2,2 :6 ,2 -terpyridine poa perfluorooctanoylacetate Tris 2-amino-2-(hydroxymethyl)- pom perfluorooctanoylmethanate propane-1,3-diol POM polyoxometalates Trp tryptophan pos bis(perfluorooctylsulfonyl)- TSAP twisted square antiprism aminate tta thenoyltrifluoro-acetylacetonate PS Phthalexon S TTP tetra-para-tolylporphyrinate PSS polystyrene sulfonate UPT up-converting phosphor PVK poly-(N-vinylcarbazole) technology PVV poly(phenylene–vinylene) WDM wavelength division multiplexer py pyridine Wt% weight percent P-FiPMA polyhexafluoroisopropylmeth- YAG yttrium aluminum garnet acrylate YLF yttrium lithium fluoride qb 4-(4-(3-triethyoxysilylpropoxy)- XO xylenol orange phenylazo)-phenyl-diphenyl phosphine oxide LANTHANIDE NEAR-INFRARED LUMINESCENCE IN MOLECULAR PROBES AND DEVICES 221 1. Outline and scope of the review Trivalent lanthanide ions offer a wide variety of opportunities to spectrochemists in that their [Xe]4fN electronic configuration generates numerous electronic levels, up to 3432 for GdIII, for instance. These ions display three types of electronic transitions. Charge transfer transi- tions, both ligand-to-metal (LMCT) and metal-to-ligand (MLCT), are allowed by Laporte’s selection rule. Their energy is usually high, so that they appear in the UV above 40 000 cm−1, except for the ions which may be relatively easily either reduced to their +2 state (SmIII,EuIII, TmIII,YbIII), or oxidized to their +4 state (CeIII,PrIII,TbIII). In these cases, the broad charge transfer transitions may occur at energies as low as 30 000 cm−1.