Density functional theory computations are employed to investigate the geometric, electronic, and vibrational properties of a neutral Ti(aniline) experimentally soft-landed onto an alkanethiol self-assembled monolayer (CH-SAM) matrix. Five optimized structures of a bare Ti(aniline) are obtained: Three of the five optimized structures show Ti-phenyl ring bonds with singlet, triplet, and quintet spin states and the other two show Ti-N bonds with triplet and quintet states. For their calculated IR spectra in the range 0-2000 cm -1, the peak position and intensity of the NH2 scissor mode (∼1600 cm-1) are insensitive to the Ti binding and spin states, whereas those of the NH2-C6H5 intergroup stretching (∼1200 cm-1) and NH2 inversion (500-1000 cm-1) modes are sensitive to these factors. To study Ti(aniline) in a CH-SAM matrix, geometric structures of a modeled system of Ti(aniline)-C3H8 are optimized and their infrared reflection absorption spectra are directly calculated by projecting the normal mode derivatives of the dipole moment of the system onto the surface normal. C3H8 stabilizes Ti(aniline) by about 8-10 kcal/mol but causes little change in the IR spectrum in the range 1300-1700 cm-1, except for the quintet state. From a comparison of the predicted IRAS spectra with the experiment, Ti(aniline) in CH-SAM is concluded to be in a triplet state with a Ti-phenyl ring bond.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films