TY - JOUR
T1 - Structure and stability of the Al14 halides Al 14in- (n=1-11)
T2 - Can we regard the Al 14 core as an alkaline earthlike superatom?
AU - Han, Young Kyu
AU - Jung, Jaehoon
PY - 2006
Y1 - 2006
N2 - We have studied the structures and stabilities of Al14I n- (n=1-11) clusters at the density functional level of theory. The experimentally observed Al14In- (n=3, 5,7, 9, and 11) [Bergeron et al., Science 307, 231 (2005)] are found to be stable both kinetically and thermodynamically. Al14I 3-, not Al14I-, is the first member of the Al14In- series in the mass spectrometric experiment, which is ascribable to the low kinetic stability of the Al 14I- cluster. The Al14 core in Al 14I3- is close to neutral Al14, both electronically and structurally. Population analysis shows that charge transfer occurs from the Al cluster to the I atoms, where the populations for Al 14 vary from -0.70(Al14I-) to +0.96(Al 14I11-). The Al14I5 - and Al14I7- clusters have the structure of Al14I3- as a core framework, but, for n = 9 and 11, we found many more stable isomers than the isomers having the Al14I3- core. In particular, the shape of Al14 in the Al14I11- cluster is a hexagonal wheel-shaped form, which was observed in the x-ray experiment for the metalloid complex [Al14{N(SiMe3)2} 6I6Li(OEt2)2] -[Li(OEt2)4]+ toluene [Köhnlein et al., Angew. Chem., Int. Ed. 39, 799 (2000)]. We have demonstrated that a simple jellium model cannot describe the structure and stability of the iodine-doped aluminum clusters, although it is successful for describing those of aluminum clusters. The electronic and geometric changes of the Al 14- cluster due to the presence of iodines are very similar to the case of a magic cluster Al13-. It can be concluded from our electronic and structural analysis that one cannot regard the Al14 core as an alkaline earthlike superatom in the Al14 iodide clusters.
AB - We have studied the structures and stabilities of Al14I n- (n=1-11) clusters at the density functional level of theory. The experimentally observed Al14In- (n=3, 5,7, 9, and 11) [Bergeron et al., Science 307, 231 (2005)] are found to be stable both kinetically and thermodynamically. Al14I 3-, not Al14I-, is the first member of the Al14In- series in the mass spectrometric experiment, which is ascribable to the low kinetic stability of the Al 14I- cluster. The Al14 core in Al 14I3- is close to neutral Al14, both electronically and structurally. Population analysis shows that charge transfer occurs from the Al cluster to the I atoms, where the populations for Al 14 vary from -0.70(Al14I-) to +0.96(Al 14I11-). The Al14I5 - and Al14I7- clusters have the structure of Al14I3- as a core framework, but, for n = 9 and 11, we found many more stable isomers than the isomers having the Al14I3- core. In particular, the shape of Al14 in the Al14I11- cluster is a hexagonal wheel-shaped form, which was observed in the x-ray experiment for the metalloid complex [Al14{N(SiMe3)2} 6I6Li(OEt2)2] -[Li(OEt2)4]+ toluene [Köhnlein et al., Angew. Chem., Int. Ed. 39, 799 (2000)]. We have demonstrated that a simple jellium model cannot describe the structure and stability of the iodine-doped aluminum clusters, although it is successful for describing those of aluminum clusters. The electronic and geometric changes of the Al 14- cluster due to the presence of iodines are very similar to the case of a magic cluster Al13-. It can be concluded from our electronic and structural analysis that one cannot regard the Al14 core as an alkaline earthlike superatom in the Al14 iodide clusters.
UR - http://www.scopus.com/inward/record.url?scp=33748262991&partnerID=8YFLogxK
U2 - 10.1063/1.2236114
DO - 10.1063/1.2236114
M3 - Article
AN - SCOPUS:33748262991
SN - 0021-9606
VL - 125
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 8
M1 - 084101
ER -