The gas-phase ion chemistry of BF3/HN3 mixtures was investigated by the joint application of mass spectrometric techniques and theoretical methods. The addition of BF2+ to HN3 led to the first observation of [BFnNxHn-1](+) (n = 1, 2; x = 1, 3) ions in the gas phase. Consistent with collisionally activated dissociation (CAD) mass spectrometric results, theoretical calculations performed at the B3LYP and CCSD(T) levels identified the F2B-NH-N-2(+), F2B-NH+, FB-N-3(+), and FBN+ ions as the most stable isomers on the [BFnNxHn-1](+) (n = 1, 2; x = 1, 3) potential energy surfaces. The F2B-NH+ and FBN+ ions, characterized by a triplet ground state, are formed from F2B-NH-N-2(+) and FB-N-3(+) through a spin-forbidden decomposition process. It is worth noting that F2BNH-N-2(+) is the protonated form of difluoroboron azide, BF2N3, a neutral molecule that has never been experimentally detected. The application of theoretical and experimental methods allowed evaluation of the unknown PA of BF2N3, Whose best theoretical estimate 171.2 +/- 3 kcal mol(-1) at the CCSD(T) level is comparable with the experimental one, 170.1 +/- 3 kcal mol(-1). The main interest of all these ionic species is represented by their possible application in boron nitride (BN) physical and chemical vapor deposition.
Gas-phase ion chemistry of BF3/HN3 mixtures: the first observation of [BFnNxHn-1]+ (n=1,2; x=1,3) ions
ROSI, Marzio
2006
Abstract
The gas-phase ion chemistry of BF3/HN3 mixtures was investigated by the joint application of mass spectrometric techniques and theoretical methods. The addition of BF2+ to HN3 led to the first observation of [BFnNxHn-1](+) (n = 1, 2; x = 1, 3) ions in the gas phase. Consistent with collisionally activated dissociation (CAD) mass spectrometric results, theoretical calculations performed at the B3LYP and CCSD(T) levels identified the F2B-NH-N-2(+), F2B-NH+, FB-N-3(+), and FBN+ ions as the most stable isomers on the [BFnNxHn-1](+) (n = 1, 2; x = 1, 3) potential energy surfaces. The F2B-NH+ and FBN+ ions, characterized by a triplet ground state, are formed from F2B-NH-N-2(+) and FB-N-3(+) through a spin-forbidden decomposition process. It is worth noting that F2BNH-N-2(+) is the protonated form of difluoroboron azide, BF2N3, a neutral molecule that has never been experimentally detected. The application of theoretical and experimental methods allowed evaluation of the unknown PA of BF2N3, Whose best theoretical estimate 171.2 +/- 3 kcal mol(-1) at the CCSD(T) level is comparable with the experimental one, 170.1 +/- 3 kcal mol(-1). The main interest of all these ionic species is represented by their possible application in boron nitride (BN) physical and chemical vapor deposition.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
