LONG RANGE CHARGE TRANSPORT IN LARGE SCALE CHEMICAL

LONG RANGE CHARGE TRANSPORT IN LARGE SCALE CHEMICAL SYSTEMS AND DNA

ELECTRON TRANSFER FROM ISOLATED MOLECULES TO BIOMOLECULES ELECTRON TRANSFER PROCESSES CONSTITUTE UBIQUITOUS AND FUNDAMENTAL PHENOMENA IN CHEMISTRY , PHYSICS AND BIOLOGY. NONRADIATIVE PROCESSES ENCOMPASSING ELECTRON / HOLE TRANSFER IN : • LARGE MOLECULES • CLUSTERS / NANOSTRUCTURES • CONDENSED PHASE • INTERFACES • PROTEIN / DNA PROCESSES : • CHARGE SEPARATION • MIGRATION • RECOMBINATION • LOCALIZATION AS WELL AS CHARGE TRANSPORT AMONG A LARGE NUMBER OF CONSTITUENTS.

An “artist’s view” of metal-ammonia solution. A lump of sodium dissolving in pure liquid ammonia produces a blue solution in which each Na atom undergoes the ET process Na Na+ +eam to form the solvated electron in ammonia. Small pieces of metal ejected into the solution result in the dark blue streaks.

Charge Transport • Large Scale Chemical Systems ØDendrimers ØPieces of Graphite • DNA • Polymers Charge Transport on the Nanoscale Charge Transfer between Nanostructures CHARGE TRANSFER &TRANSPORT Molecular Electronics • Supramolecules • Molecular Wires • Molecular Materials for Electronics and Optoelectronics • Single Molecule Electronic Devices Nanoelectronics • Clusters/Nanostructures / Nanotubes…. . • Nanowires • Nanomaterials for Electronics and Optoelectronics • Single Electron Nanodevices Coulomb Blockade/ Transistor/ Rectifier

MOLECULAR WIRES AND NANOWIRES NANOSTRUCTURES, WHOSE SPATIAL CONFIGURATION, ENERGETICS, NUCLEAR AND ELECTRON DYNAMICS PROMOTE LONG-RANGE CHARGE TRANSPORT

THE WORLD OF MOLECULAR AND NANOWIRES 1. NANOWIRES (NANOSCALE IN 2 D) d • METALLIC T=1 Transmittance g = h/2 e 2 Conductance Quantization (Landauer) • SEMICONDUCTOR Confinement Effects BAND GAP 2. MOLECULAR WIRES • SUPEREXCHANGE MEDIATORS • ‘VIBRONIC’ WIRES • BAND TRANSPORT WIRES

MOLECULAR WIRES ALKENES, AROMATIC HYDROCARBONS, SINGLE MOLECULE OR SUPRAMOLECULE, POLYPEPTIDES, PROTEINS, SELF-ASSEMBLED LAYERS, POLYMERS, DNA (1) INCOHERENT ONE-STEP OR MULTISTEP HOPPING • SUPEREXCHANGE MEDIATOR • MULTISTEP HOPPING IN VIBRONIC WIRES • THERMALLY ACTIVATED INJECTION AND HOPPING IN VIBRONIC WIRES ENERGETIC CONTROL (2) COHERENT BAND TRANSPORT

THE ROLE OF BRIDGES OFF-RESONANCE & RESONANCE COUPLING B D (A) OFF - RESONANCE SUPEREXCHANGE A COUPLING D+B-A DBA UNISTEP ET D+BA- (B) RESONANCE COUPLING } DBA VR D+B-A D+BA- MULTISTEP ET SEQUENTIAL /COHERENCE LENGTH

‘ POOR’ & ‘GOOD’ MLECULAR VIBRONIC WIRES J. JORTNER et al. Proc. Natl. Acad. USA (1998) ENERGETICS OF ION-PAIR STATES CONTROLS ET ROUTE D* B A SUPEREXCHANGE UNISTEP OFF- RESONANCE SEQUENTIAL RESONANCE 2 TYPES OF MOLECULAR VIBRONIC WIRES ‘POOR’ SUPEREXCHANGE Ø OFF-RESONANCE Ø UNISTEP Ø EXPONENTIAL ‘GOOD’ RESONANCE Ø (VIBRONIC) COUPLING Ø CHARGE INJECTION TO BRIDGE Ø DIFFUSIVE (OR COHERENT) CHARGE TRANSPORT Ø MULTISTEP Ø ALGEBRAIC ENERGETIC CONTROL BY SEQUENCE SPECIFICITY OF BRIDGE IS UNIVERSAL FOR LARGE MOLECULAR SCALE SYSTEMS FOR PROTEINS AND DNA

‘ POOR’ & ‘GOOD’ MLECULAR VIBRONIC WIRES J. JORTNER et al. Proc. Natl. Acad. USA (1998) ENERGETICS OF ION-PAIR STATES CONTROLS ET ROUTE D* B A SUPEREXCHANGE UNISTEP OFF- RESONANCE • SEQUENTIAL RESONANCE 2 TYPES OF MOLECULAR WIRES ‘POOR’ SUPEREXCHANGE Ø OFF-RESONANCE Ø UNISTEP Ø EXPONENTIAL • ‘GOOD’ RESONANCE Ø (VIBRONIC) COUPLING Ø CHARGE INJECTION TO BRIDGE Ø DIFFUSIVE (OR COHERENT) CHARGE TRANSPORT Ø MULTISTEP Ø ALGEBRAIC ENERGETIC CONTROL BY SEQUENCE SPECIFICITY OF BRIDGE IS UNIVERSAL FOR LARGE MOLECULAR SCALE SYSTEMS FOR PROTEINS AND DNA

DONOR ACCEPTOR O O WIRE N N C 8 H 17 O O WIRE=1. 2. . R=2 - ETHYLHEXYL RO 3. 4. 5. RO RO RO W. B. DAVIS, W. A. SVEC, M. A. RATNER & M. R. WASIELEWSKI NATURE (1999)

HOLE TRANSPORT IN DNA B. GIESE AND M. E. MICHEL-BEYERLE (1999) G+ BRIDGE GGG ln krel 3 40 R / A 4 N 20 2 10 1 2 1 0 0 C C C A A C G G G T T G+ 10 1. 5 0. 5 1. 0 ln N C C C A A C G G G T T G+ 20 C C C A A A A A C G G G T T+ G 40 R/A

ELECTRON TRANSPORT IN DNA • ET VIA T NUCLEOBASE M. BIXON, J. JORTNER, M. E. MICHEL-BEYERLE et al. PROC. NATL. ACAD. SCI. USA (1999) • HOPPING TRANSPORT B. GIESE (2003) INJECT e 20 k. ET/ktr 10 5 =1. 1 2 1 1 2 3 n

QUANTIFYING ENERGETIC CONTROL E O E < O UNISTEP SUPEREXCHAGE MULTISTEP HOPPING k. CT = ksuper k. CT = k n- INDIVIDUAL HOPPING RATES SUPEREXCHANGE RATE ELEMENTARY RATES DESCRIBED BY THEORY OF CHARGE TRANSFER DYNAMICS E(Q) V~ ~~ DA ~~~~~ ~~~ {D+A-} VIBRONIC MANIFOLD Q CHARGE TRANSFER KINETICS J. FRANCK (1949) R. A. MARCUS (1956) V. LEVICH (1965) CHARGE TRANSFER DYNAMICS (1974 -)

CHARGE TRANSFER AND TRANSPORT IN ORGANIZED SYSTEMS • MOLECULAR LARGE - SCALE • PHOTOSYNTHETIC RC • POLYNUCLEOTIDES AND DNA FOCUSING ON : INGREDIENTS ET RATE V 2 F STRUCTURE BRIDGING ELECTRONIC STATES ELECTRONIC COUPLING V ENERGETICS IONIC STATES STRUCTURAL NUCLEAR FC FACTORS CONTROL NUCLEAR DYNAMICS V- ELECTRONIC COUPLING EXCHANGE / SUPEREXCHANGE DA SEPARATION / ORIENTATION BRIDGES F

ET RATE V 2 F F - NUCLEAR FRANCK - CONDON FACTOR ENERGETICS COUPLING TO INTRAMOLECULAR VIBRATION COUPLING TO MEDIUM MODES ENERGETIC VIBRONIC MEDIUM CONTROL

THE ELECTRONIC COUPLING CHARGE TRANSFER / TRANSPORT DNA IN SOLUTION A. A. Voityuk, N. Rösch, M. Bixon, J. Jortner, J. Phys. Chem. 104 B, 1661 (2000) J. Chem. Phys. 114, 5614 (2001) MOLECULAR ELECTRONICS OF DNA

HOLE HOPPING IN G+(X)m. G DUPLEX 103 X=T, A GTG V=Aeb. R k e- R b= 0. 44 A-1 =0. 88 A-1 102 1 2 V(cm-1) 10 GTTG CALCULATED GTTTG WITH SOLVENT 3 DEPENDENT ENERGY GAP GTTTTG 1 EXPERIMENTAL 10 -1 (1) GAG (LEWIS, WASIELEWSKI) (2) St-AAG (LEWIS, WASIELEWSKI) (3) m=3 (HARRIMAN) =0. 7 -0. 9 A-1 10 -2 0 1 ( LEWIS, WASIELEWSKI, GIESEL, MICHEL-BEYERLE) 2 m 3 4

SUPEREXCHANGE

BEYOND ENERGETIC CONTROL N X UNITS E 0 X k k X k-1 kt k -t E k k k 1 X Ea ksuper d 2 PARALLEL MECHANISMS a • SUPEREXCHANGE • THERMAL ACTIVATION AND INTRABRIDGE HOPPING THERMALLY-INDUCED HOPPING (TIH) ksuper exp(- Ro. N) k. TIH K k/N 2 N x CROSSOVER SUPEREXCHANGE TIH

|Vsuper|2 SUPEREXCHANGE TIH |V eff |2 -3 10 -4 10 TIF -5 10 -6 10 nx -7 10 -8 nx 10 -9 10 1 2 3 n 4 5 6

Expt. V. Sartor, E. Boone, G. B. Schuster J. Phys. Chem. (2001) Theory J. Jortner, M. Bixon, N. Rosch. J. Phys. Chem. (2002) 1. 0 0. 5 0. 2 N expt. calc. 2 0. 1 5 N N k/kd 2 15 3 4 1 4 5 1 5 4 1 Invariance for N > 3

Direct observation of hole transfer through DNA by hopping between adenine bases and by tunneling Bernd Giese , Jérôme Amaudrut, Anne-Kathrin Köhler, Martin Spormann & Stephan Wessely NATURE | VOL 412 | 19 JULY 2001 , pp 318 -320

T E(G-T) T A k G T T k A k k k-1 k 1 kt k-t Et ksuper exchange E GGG

Theoretical Nx for Superexchange TIH

RECENT HISTORY GIESE’S KINETIC ARGUMENT HAS TO BE EXTENDED DRIVEN BY GATING MECHANISMS

E(G-T) T A k k G T T T A k k A k-1 k 1 k kt k-t Et ksuper exchange E GGG First order model: regular, homogeneous bridge

THERMALLY INDUCED HOPPING (TIH) First order model-regular homogeneous bridge It is impossible to construct a plausible consistent set of parameters that will give a reasonable fit to the experiment ! The model is too crude ; it should be modified to include finer details of the real system.

Energetics of Transient Hole Trapping In an AT n Bridge A+ T Edge Groups Provide Energetic Barriers Energetic Data : A. Voityuk, N. Rösch, M. Bixon, J. Jortner, Chem. Phys. Lett. (2000) - 3’ 5’- C A G T E(e. V) 0. 7 0. 6 CA+A GT T 0. 5 AA+A TT G AA+A TT T 0. 4 CAA 0. 3 GTT 0. 2 0. 1 0 AC C TG+G

E(G-T) T A T T k-2 k 2 k A k G T k-2 k A k k-1 k 1 A kt k-t Et ksuper exchange E GGG

103 102 Superexchange R 101 ENERGETIC GATING BY SHALLOW TRAPS TIH – two state bridge 100 10 -1 0 TIH – ho 5 10 n mogenou s bridge 15 20 PARAMETERS Energies Rate constants (Relative values k=1) 25

MOLECULAR VIBRONIC WIRES DNA • CHARGE HOPPING BETWEEN LOCALIZED STATES • INCOHERENT HOPPING TRANSPORT • EACH HOPPING STEP INVOLVES ELEMENTARY CHARGE TRANSFER BETWEEN IDENTICAL NUCLEOBASES QM CT THEORY V 2 F • MECHANISM FOR HOLES IN DNA ‘RESTING STATES’ G + - - - G + TIH A A • ‘MOLECULAR POLARON’ (G/A)(+) (T/C)(-) MODEL FOR HOLES AND ELECTRONS TRANSPORT IN DNA / SOLUTION

HOPPING INCOHERENT TRANSPORT IN MOLECULAR WIRES ü • UNISTEP SUPEREXCHANGE MEDIATOR ü • MULTISTEP HOPPING IN VIBRONIC WIRES ü • TIH IN VIBRONIC WIRES WHAT ABOUT COHERENT BAND TRANSPORT ?

Hole Conduction along Molecular Wires: -Bonded Silicon Versus -Bond-Conjugated Carbon By Ferdinand C. Grozema, Laurens D. A. Siebbeles, John M. Warman, Shu Seki, Seiichi Tagawa, and Ulrich Scherf + The molecular structures of the polymers investigated in the present work together with their pseudonyms (left) and onedimensional, intrachain hole mobilities (hp+) [cm 2/Vs] (right) determined from the experimental data. Adv. Mater. 2002, 14, No. 3, February 5

Highly Mobile Electrons and Holes in Semiconducting Polymer Chains J. M. Warman et. al. Nature 392, 54 (1998) Adv. Mat. 14, 228 (2002) Poly- Phenylene Vinylene +=0. 43 cm 2/Vsec In a Series of Polymer Chains DEH-PF, MEH-PPV, MELPP Hole Mobility +=0. 2 - 0. 8 cm 2 / Vsec Charge Mobility in 2 D Finite Graphite K. Müllen, 6 th International Symposium of Volkswagen-Foundation (2003) _= 1 cm 2/Vsec WEAK T DEPENDENCE Technology: Field Effect Transistors Light Emitting Diodes

IMPLICATIONS OF HIGH MOBILITY 2 1 cm / Vsec Diffusion Coefficient For L = 50Å t = L 2/2 D t = 10 ps Distance Scale ‘Long Range’ Transport Ultrashort Time Scale ‘Long Range’ Transport NOTE: For Hopping Transport, ET Theory Gives Beyond Hopping Transport ! Å

50 - 100Å) Long – Range (L Ultraslow (µs) and Ultrafast (ps) Charge Transport in Molecular Wires Electronic Coherence in Band Transport scatt - Time For Memory Loss of Electronic Coherence Compare Bandwidth B=2 V Incoherent Hopping Transport Mean Free Path a – ‘Lattice’ Spacing With V a Coherent Band Transport Strong Scattering

CHARGE TRANSPORT DOMAINS IN LARGE SCALE SYSTEMS scatt HOPPING INCOHERENT Rate of TRANSPORT Memory Loss B=2 V Band Width BAND STRONG SCATTERING V a BAND COHERENT TRANSPORT a Mean Free Path

Mobilities µ for Ultraslow (µs) and Ultrafast (ps) Charge Transport V V k Hopping Band Incoherent Coherent Strong Transport Scattering Transport Charge Mobility Classical Expression Quantum-Mechanic Expression Numerical Estimate V=0. 1 e. V a=3Å s =0. 5 e. V S=2 k=109 s-1 Experiment µ 2 • 10 -5 µ 1 cm 2/Voltsec Narrow Band For DNA µ= 0. 1 - 1. 0 cm 2/Voltsec for PPV

ELECTRIC PROPERTIES OF DNA CONJECTURES AND REPORTS ON: UNDOPED DNA CONFLICTING INSULATOR SEMICONDUCTOR METALLIG SUPERCONDUCTING CURRENT THEORY FOR UNDOPED DNA: LARGE GAP , NARROW BANDWIDTH WSEMICONDUCTOR CB EG W+ , W- ~ 0. 01 – 0. 1 e. V VB W+ EG 3 - 4 e. V • ROLE OF CHEMISTRY • SUBSTITUTIONAL • TIH IN DNA (TIH) 0. 25 e. V TIH GAP SEQUENCE POLY SPECIFICITY G DNA LOCALIZED DISORDER STATES+ HOPPING + TIH ~ 0. 3 e. V G+ ‘BAND’ A+ ‘BAND’ B. GRUNER et al. , PHYS. REV. LETT. 85, 1564 (2000) • DIAGONAL DISORDER AND LOCALIZATION OFF – DIAGONAL DISORDER • CHARGE INJECTION • CONTROL DOPING

MOLECULAR ELECTRONICS OF DNA • ELECTRONIC PROPERTIES OF A BASIC BIOPOLYMER • DYNAMICS, RESPONSE AND FUNCTION OF NANOSTRUCTURES AND BIOSENSORS • DNA BASED MOLECULAR ELECTRONICS UTILIZING UNIQUE FEATURES OF RECOGNITION ASSEMBLY SPECIFIC BINDING OF NUCLEOBASES • DNA DUPLEXES AS CONDUCTIVE BLOCKS OR AS INSULATING / CONDUCTING TEMPLATES FOR ASSEMBLY OF OTHER NANOELEMENTS, E. G. , METAL CLUSTERS ‘THEORETICIANS DREAMS’ DYNAMICS OF CHARGE TRANSFER AND TRANSPORT IN DNA

50 nm AFM IMAGE OF Au NANOPARTICLE WIRE GENERATED ON DNA TEMPLATE Au NANOPARTICLES 1. 3 nm INTERCALATED INTO POLY T / POLY A WIRE LENGTH 500 -600 nm WIDTH 3. 5 – 8. 0 nm (I. WILNER, PAC 2000)

CHARGE TRANSPORT ON THE NANOSCALE • MOLECULAR WIRES IDENTIFIED AND DESCRIBED IN LARGE–SCALE CHEMICAL SYSTEMS / DNA / POLYMERS • SUPEREXCHANGE MEDIATORS • VIBRONIC WIRES: HOPPING TIH • BAND TRANSPORT • POLYMERS / BIOPOLYMERS / DNA AS • • TEMPLATES FOR NANOSTRUCTURES NANOWIRES BUILT FROM NANOSTRUCTURES (SUPERNANOSTRUCTURES) SELF ASSEMBLY CHARGE TRANSPORT IN SUPERNANOSTRUCTURES PARAMETERS OF ET BETWEEN ELEMENTS OF SUPERNANOSTRUCTURES ELECTRONIC LEVEL STRUCTURE OF SINGLE NANOSTRUCTURES MNMT V – COHERENT TRANSPORT V 2, F – INCOHERENT HOPPING FC PARAMETERS, SOLV , SMALL FOR NANOSTRUCTURES BAND • ELECTRONIC LEVEL STRUCTURE AND TRANSPORT IN SUPERNANOSTRUCTURES

PERSPECTIVES • UNIFICATION PROPHECY DID DISAPPEAR JEWISH PROVERB 1 AD ØFROM SHORT- RANGE CHARGE TRANSFER TO LONG - RANGE CHARGE TRANSPORT ØFROM HOPPING, INCOHERENT, LONG-TIME ( s) TRANSPORT TO BAND, COHERENT, SHORT-TIME (ps) TRANSPORT • DYNAMIC FOUNDATIONS FOR MOLECULAR – SCALE MATERIAL SCIENCE INTERFACIAL NANO - SCALE BIOMATERIAL MOLECULAR AND NANO ELECTRONICS BECOMING A LEGITIMATE EXCITING FIELDS • PURE ELECTRONIC PROCESSES BEAT CONSTRAINTS IMPOSED BY FRANCK - CONDON PRINCIPLE J. FRANCK (1949) TODAY IN COMPLEX SYSTEMS

MOLECULAR ELECTRONICS NANOELECTRONICS IN PERSPECTIVE THE FIRST 30 YEARS 1959 -1990 VISION AND ENTHUSIASM RATHER THAN RIGOROUS SAMPLE PREPARATION / CHARACTERIZATION CONCEPTS THE LAST DECADE 1990 THE METAMORPHOSIS • PREPARATION SYNTHESIS, NANOFABRICATION, LITHOGRAPHY SELF ASSEMBLY • INTERROGATION & MANIPULATION MOLECULAR IMAGING, STM, AFM • CONCEPTUAL FRAMEWORK BASIC PROCESSES, ELECTRON / PROTON TRANSFER, CLUSTER SIZE EFFECTS / SCALING, NANOELECTRONICS, BIO-NANOSYSTEMS, DNA GRAND VISION COMING TRUE !