Synthesis and formation mechanism of hydrogenated boron clusters B(12)H(n) with controlled hydrogen content.

We present the formation of hydrogen-content-controlled B(12)H(n) (+) clusters through the decomposition and ion-molecule reactions of the decaborane (B(10)H(14)) and diborane (B(2)H(6)) molecules in an external quadrupole static attraction ion trap. The hydrogen- and boron-contents of the B(10-y)H(x) (+) cluster are controlled by charge transfer from ambient gas ions. In the process of ionization, a certain number of hydrogen and boron atoms are detached from decaborane ions by the energy caused by charge transfer. The energy caused by the ion-molecule reactions also induces H atom detachment. Ambient gas of Ar leads to the selective generation of B(10)H(6) (+). The B(10)H(6) (+) clusters react with B(2)H(6) molecules, resulting in the selective formation of B(12)H(8) (+) clusters. Ambient gas of Ne (He) leads to the generation of B(10-y)H(x) (+) clusters with x=4-10 and y=0-1 (with x=2-10 and y=0-2), resulting in the formation of B(12)H(n) (+) clusters with n=4-8 (n=2,4-8). The introduction of ambient gas also increases the production of clusters. PBE0/6-311+G(d)//B3LYP/6-31G(d)-level density functional theory calculations are conducted to investigate the structure and the mechanism of formation of B(10-y)H(x) (+) and B(12)H(n) (+) clusters.