Journal ArticleTriatomic BNB has been produced by laser ablation of a boron nitride rod in a supersonic expansion of helium carrier gas and has been investigated using resonant two-photon ionization spectroscopy in the visible region. The B? 2IIg?X? 2?u + band system has been recorded near 514 nm and is dominated by a strong origin band, which has been rotationally resolved and analyzed. Both the 11B14N11B (64% natural abundance) and the 10B14N11B (32% natural abundance) isotopic modifications have been analyzed, leading to the spectroscopic constants (and their 1 error limits) of B"0(X? 2?u+)=0.466 147(70), B'0(B? 2IIg)=0.467 255(75), and A'0(B? 2IIg)=6.1563(38) cm?1 for 10B14N11B, corresponding to r"B ?N(?X 2?u+)=1.312 47(10) ? and r"B ?N(?B 2IIg)=1.310 92(11) ?. Very similar values are obtained for the more abundant isotopomer, 11B14N11B: B'0(X? 2?u+) =0.444 493(69), B'0(B? 2IIg)=0.445 6069(70), A'0(B? 2IIg)=6.1455(38) cm?1, corresponding to r"B ?N(?X 2?u+)=1.312 41(10) ? and r'b ?N(?B 2IIg)=1.310 77(10) ?. These results are discussed as they relate to Walsh?s rules and are compared to results for related molecules
