List of Figures

1.1 Chemical structure of the simplest porphyrin, Porphin
2.1 Schematic of the Auger process
2.2 Auger spectrum of a Mo sample contaminated by O and C
2.3 Auger electron spectroscopy apparatus.
2.4 Diagram of Bragg diffraction
2.5 The Ewald sphere construction
2.6 Experimental apparatus for low energy electron diffraction, LEED pattern recorded from the clean Mo(110) surface
2.7 Schematic of tunneling through a potential barrier
2.8 Diagram illustrating the difference between the constant current and constant height modes
2.9 Photograph of the Createc LT-STM system
2.10 Photograph of the Omicron VT-STM system
2.11 A model XAS spectrum
2.12 Schematic diagram showing the designation of XAS transitions according to their core energy level
2.13 Comparison of the 3s and 3p all-electron wavefunctions and pseudo-wavefunctions calculated for Si
2.14 Illustration of the Dirac step function and smearing
3.1 Room temperature STM of C60 monolayer domains on the Au(111) surface
3.2 Schematic of the 7×7 R14 superstructure of C 60 on Au(111)
3.3 C60 trilayer on Ag/Si(111)-√ --
  3×√ --
  3 R30 with schematic of dimer and trimer formation
3.4 STM of C60 trilayer showing single-molecular writing, erasing and rewriting
3.5 Diagram of the high-symmetry orientations of C60
3.6 STM image and LEED of the WO2/W(110) surface
3.7 Top and side view of the WO2/W(110) surface
3.8 Low-temperature STM images acquired after the deposition of various coverages of C60 molecules onto the WO2/W(110) surface
3.9 STM image of the closed C60 monolayer on WO2/W(110)
3.10 STM image of C60 on the WO2/W(110) surface, showing chains of the ‘dim’ molecules
3.11 Low-temperature STM image of C60 on the WO2/W(110) surface showing orbital ordering
3.12 STM images of the C60 monolayer showing the different cooling regimes and temperature-dependant behaviour
3.13 Squared probability of finding a static C60 molecule, p2, versus temperature, T.
3.14 Dynamics of the transitions between different molecular states of a C60 monolayer at T = 256K.
3.15 STM image demonstrating the decoration of the WO2 rows of the underlying substrate surface by dim C60 molecules and chains of spinning molecules
3.16 Model showing possible absorption sites on WO2/W(110)
3.17 Partial charge density simulations of static and composite images of spinning molecules
3.18 STM images of individual spinning molecules with a dip or a protrusion at the centre
3.19 STM images of the same area of the C60 monolayer showing a molecule switching between different states
3.20 STM showing that very bright molecules are predominantly located along the top of the oxide nanorows
3.21 STM image showing the h–p orientation of very bright C60 molecules
3.22 The time-evolution of the STM tip-surface distance above a switching C60 molecule
3.23 The calculated density of states (DOS) for C60 and C 60 on the WO2/W(110) surface
3.24 The apparent height difference ΔZ between the C60 and the C 60 molecules
3.25 Cross sections of the Fukui functions f+(r) and f(r) along the h–h and h–p bonds
4.1 STM of increasing NiP coverages on Ag(111)
4.2 STM of approximately 1.8 ML coverage of NiP on Ag(111), showing single-molecular missing rows
4.3 STM of 1 ML of NiTPP-dimers on the Ag(111) surface
4.4 Schematic models of the silver body-centred cubic structure and Ag(111) surface
4.5 Top and side-view model of the Ag/Si(111)-√--
 3×√ --
  3 R30 surface
4.6 Molecular model of (5,15-diphenylporphyrinato)Ni(II)
4.7 STM images taken from 1 ML of the NiDPP on the Ag(111) surface, and NiDPP overlayer model
4.8 STM images taken from 1 ML of the NiDPP on the Ag(111) surface showing alignment with the step-edges
4.9 LEED pattern and 2D-FFT taken from NiDPP on the Ag(111) surface
4.10 STM image taken from 1 ML of the NiDPP on the Ag/Si(111)-√ --
  3×√ --
  3 R30 surface showing the three domains
4.11 Comparison of LEED and 2D-FFT of NiDPP on Ag/Si(111)- √ --
  3×√ --
  3 R30
5.1 Symbolic structural and ball-and-stick models of MnClTPP
5.2 Model and liquid-cell STM images of Mn1 molecule on Au(111) grown on mica
5.3 STM image of the Mn1 monolayer after a large proportion of the molecules have been oxidised, and histograms comparing statistical models
5.4 STM images from 0.15ML of MnClTPP and a monolayer island showing the chirality within the molecular overlayer
5.5 Relaxed models of MnClTPP on Ag(111) and comparison with STM, showing packing and buckling in the monolayer
5.6 STM images of 1 ML of MnClTPP showing the Cl-ligand at positive bias
5.7 Mn 2p XAS spectra acquired during the anneal and oxygen exposure of the Mn(III)ClTPP monolayer
5.8 STM images of 1 ML of MnTPP after annealing
5.9 Relaxed models calculated for Mn(III)ClTPP and Mn(III)TPP on Ag(111)
5.10 Cl 2p XPS taken while annealing the MnClTPP molecules at varying temperatures, and Arrhenius plot derived from the XPS intensities
5.11 STM images of 1 ML Mn(IV)O2TPP after various oxygen exposures
5.12 Relaxed model of the MnO2TPP after oxidation
5.13 O 1s XPS taken during the anneal of the Mn(IV)O2TPP ML and accompanying Arrhenius plot