Resonant two-photon ionization spectroscopy of BNB

Triatomic 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 (2)Pi(g)-X (2)Sigma(+)(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 (BNB)-B-11-N-14-B-11 (64% natural abundance) and the (BNB)-B-10-N-14-B-11 (32% natural abundance) isotopic modifications have been analyzed, leading to the spectroscopic constants (and their 1 sigma error limits) of B-0(')(X (2)Sigma(+)(u))=0.466 147(70), B-0(')(B (2)Pi(g))=0.467 255(75), and A(0)(')(B (2)Pi(g))=6.1563(38) cm(-1) for (BNB)-B-10-N-14-B-11, corresponding to r(B-N)(')(X (2)Sigma(+)(u))=1.312 47(10) A and r(B-N)(')(B (2)Pi(g))=1.310 92(11) A. Very similar values are obtained for the more abundant isotopomer, (BNB)-B-11-N-14-B-11: B-0(')(X (2)Sigma(+)(u))=0.444 493(69), B-0(')(B (2)Pi(g))=0.445 606(70), A(0)(')(B (2)Pi(g))=6.1455(38) cm(-1), corresponding to r(B-N)(')(X (2)Sigma(+)(u))=1.312 41(10) A and r(B-N)(')(B (2)Pi(g))=1.310 77(10) A. These results are discussed as they relate to Walsh's rules and are compared to results for related molecules. (c) 2006 American Institute of Physics.