title: Ab initio calculations on SnCl2 and Franck-Condon factor simulations of its ã-X and B-X absorption and single-vibronic-level emission spectra.
abstract: Minimum-energy geometries, harmonic vibrational frequencies, and relative electronic energies of some low-lying singlet and triplet electronic states of stannous dichloride, SnCl(2), have been computed employing the complete-active-space self-consistent-field/multireference configuration interaction (CASSCF/MRCI) and/or restricted-spin coupled-cluster single-double plus perturbative triple excitations [RCCSD(T)] methods. The small core relativistic effective core potential, ECP28MDF, was used for Sn in these calculations, together with valence basis sets of up to augmented correlation-consistent polarized-valence quintuple-zeta (aug-cc-pV5Z) quality. Effects of outer core electron correlation on computed geometrical parameters have been investigated, and contributions of off-diagonal spin-orbit interaction to relative electronic energies have been calculated. In addition, RCCSD(T) or CASSCF/MRCI potential energy functions of the X(1)A(1), ã(3)B(1), and B(1)B(1) states of SnCl(2) have been computed and used to calculate anharmonic vibrational wave functions of these three electronic states. Franck-Condon factors between the X (1)A(1) state, and the ã (3)B(1) and B (1)B(1) states of SnCl(2), which include anharmonicity and Duschinsky rotation, were then computed, and used to simulate the ã-X and B-X absorption and corresponding single-vibronic-level emission spectra of SnCl(2) which are yet to be recorded. It is anticipated that these simulated spectra will assist spectroscopic identification of gaseous SnCl(2) in the laboratory and/or will be valuable in in situ monitoring of SnCl(2) in the chemical vapor deposition of SnO(2) thin films in the semiconductor gas sensor industry by laser induced fluorescence and/or ultraviolet absorption spectroscopy, when a chloride-containing tin compound, such as tin dichloride or dimethyldichlorotin, is used as the tin precursor.
authors.affiliation: Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Edmond P F
authors.initials: EP
authors.lastname: Lee
authors.forename: John M
authors.initials: JM
authors.lastname: Dyke
authors.forename: Daniel K W
authors.initials: DK
authors.lastname: Mok
authors.forename: Wan-ki
authors.initials: WK
authors.lastname: Chow
authors.forename: Foo-tim
authors.initials: FT
authors.lastname: Chau
mesh_terms: D002627:Chemistry, Physical / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D004581:Electronics; D004583:Electrons; D005740:Gases; D008956:Models, Chemical; D012666:Semiconductors; D013050:Spectrometry, Fluorescence / Q000379:methods; D013053:Spectrophotometry / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014001:Tin / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D005740:Gases; D017971:Tin Compounds; C023599:stannous chloride; D014001:Tin