DENNIS J. CLOUTHIER, ROBERT GRIMMINGER, and BING JIN, Department of Chemistry, University of Kentucky, Lexington, KY; PHILLIP M. SHERIDAN, Department of Chemistry and Biochemistry, Canisius College, Buffalo, NY. THE X 2 BO and X 2 BS (X = HYDROGEN OR HALOGEN) FREE RADICALS

BORON CONTAINING FREE RADICALS BC BS 2 BH 2 BF 2 BCl 2 HBF HBCl HBBr X 2 BO X 2 BS

COLUMBUS MEETING 1964 OSU Knowledge Bank Dr. C. Weldon Mathews BF 3 + O 2  BO 2 + F 2 BO

EXPERIMENTAL BACKGROUND 1. The Emission Spectrum of the BOF 2 Molecule, C. Weldon Mathews and K. K. Innes, J. Mol. Spectrosc. 15, 199 (1965). 2.The 4465 Å Emission Spectrum of the BOF 2 Molecule, C. Weldon Mathews, J. Mol. Spectrosc. 19, 203 (1966). 3.B atoms, B 2 and H 2 BO Molecules: ESR and Optical Spectra at 4 K, W. R. M. Graham and W. Weltner, Jr., J. Chem. Phys. 65, 1516 (1976). H 2 BS, F 2 BS, Cl 2 BO, Cl 2 BS experimentally unknown!

H 2 BO MO PICTURE b 2 n(O) b 1  (BO) a 1  (BO) X 2 B 2...(a 1 ) 2 (b 1 ) 2 (b 2 ) 1 ~ ~ ~ B 2 A 1...(a 1 ) 1 (b 1 ) 2 (b 2 ) 2 A 2 B 1...(a 1 ) 2 (b 1 ) 1 (b 2 ) 2.

F 2 BO SYNTHESIS FOR JET SPECTROSCOPY BF 3 + O 2 + Argon

SPECTRA OF JET-COOLED F 2 BO Dr. Bob Grimminger

0-0 BAND EMISSION SPECTRUM OF F 2 10 BO CCSD(T)/aug-cc-pVQZ Dr. Phil Sheridan x3

HIGH RESOLUTION 0-0 BAND OF F 2 BO Simulation: B3LYP/aug- cc-pVQZ rotational and spin-rotation constants only

MOLECULAR STRUCTURES Å Å  X 2 B 2 ~ A 2 B 1 ~ Å Å +1.4  B 2 A 1 ~ Å Å 

THEORETICAL PREDICTIONS FOR NEW RADICALS 1.B3LYP and CCSD(T) geometry optimizations and frequency calculations with aug-cc-pVnZ (n = 3,4,5) basis sets. 2. Energies extrapolated to complete basis set limit (CBS) using E (n) = E CBS + Ae -bn (n = 3, 4 or 5 as above). 3. Franck-Condon simulations of the vibrational structure of absorption and emission spectra. 4. Rotational band contour calculations using ab initio A, B, C and  aa,  bb, and  cc constants. Tests on F 2 BO: T 0 (B state) error = +32 cm -1 T 0 (A state) error = -62 cm -1 X state vibrational freqs max error = 14 cm -1 ~ ~ ~

Franck-Condon simulations of absorption and emission spectra PREDICTIONS FOR THE H 2 BO and H 2 BS FREE RADICALS Calculated rotationally resolved contour of the 0-0 band of H 2 10 K

C 2v Trans Cis H 2 BO ISOMERS B + H 2 O  HBOH Matrix IR G. H. Jeong, R. Boucher, and K. J. Klabunde, JACS 112, 3332 (1990)

LIF IDENTIFICATION OF F 2 BS F 2 BS prepared in a BF 3 /CS 2 /Ar discharge Dr. Bing Jin

SYNTHESIS AND IDENTIFICATION OF Cl 2 BS Cl 2 BS produced by a discharge through a BCl 3 /CS 2 /Ar precursor mixture Cl 2 BS LIF spectrum Cl 2 BS 0-0 band emission spectrum Simulation B3LYP/aug-cc-pV5Z

EXPERIMENTAL VS AB INITIO T 0 VALUES F 2 BO, F 2 BS: CCSD(T)/CBS Cl 2 BS: CCSD(T)/aug-cc-pVTZ Ab Initio =

CONCLUSIONS 1. The LIF and emission spectra of jet-cooled F 2 BO have been observed and analyzed. 2.Ab initio calculations have been performed to calculate the spectra of other X 2 BO and X 2 BS radicals. 3. Extensive searches have failed to reveal the spectra of H 2 BO and H 2 BS. 4. The previously unknown F 2 BS and Cl 2 BS free radicals have been observed and their electronic spectra studied.