THE A 3-SIGMA-X1-SIGMA+(X0+) TRANSITION OF BIN( (A(1)1))

The a 3SIGMA (a(1)1)-X 1SIGMA+(XO+) radiative transition of BiN has be en observed in the near-infrared spectral region by use of the laser-i nduced fluorescence method. BiN molecules were produced by reaction of microwave-discharged nitrogen with bismuth vapour in a flow system. E leven bands of the upsilon', upsilon'' = 0, 1 progressions were measur ed in the LIF excitation spectrum between 700 and 960 nm and six upsil on'= 0, upsilon'' bands were observed in the fluorescence spectrum bet ween 1000 and 1600 nm. The vibrational isotope shifts of the band head s of (BiN)-N-14 and (BiN)-N-15 were used for identification of the abs orbing molecule and vibrational assignment. Analysis of the bands yiel ded the following molecular constants (in cm-1), X0+: omega(e)=737+/-5 , omega(e)x(e)=5+/-2; a(1)1: T(e)=10150.3+/-5, omega(e)=502.7+/-0.5, o mega(e)x(e)=4.86+/-0.04. The radiative lifetime of the a(1)1 state was found to be greater-than-or-equal-to 0.5 ms.