Aromatic pi-pi interaction mediated by a metal atom: structure and ionization of the bis(eta(6)-benzene)chromium-benzene cluster.
Aromatic pi-pi interaction in the presence of a metal atom has been investigated experimentally and theoretically with the model system of bis(eta(6)-benzene)chromium-benzene cluster (Cr(Bz)(2)-Bz) in which a free solvating benzene is non-covalently attached to the benzene moiety of Cr(Bz)(2). One-photon mass-analyzed threshold ionization (MATI) spectroscopy and first principles calculations are employed to identify the structure of Cr(Bz)(2)-Bz which adopts the parallel-displaced configuration. The decrease in ionization potential for Cr(Bz)(2)-Bz compared with Cr(Bz)(2), resulting from the increase of the cation-pi stabilization energy upon ionization, is consistent with the parallel-displaced structure of the cluster. Theoretical calculations give the detailed cluster structures with associated energetics, thus revealing the nature of pi-pi-metal or pi-pi-cation interactions at the molecular level.
Department of Chemistry, KAIST, Daejeon 305-701, Republic of Korea.
Songhee
S
Han
N Jiten
NJ
Singh
Tae Yeon
TY
Kang
Kyo-Won
KW
Choi
Sunyoung
S
Choi
Sun Jong
SJ
Baek
Kwang S
KS
Kim
Sang Kyu
SK
Kim
D000465:Algorithms; D001554:Benzene / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002857:Chromium / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis
D002412:Cations; D008670:Metals; D009942:Organometallic Compounds; D012997:Solvents; D002857:Chromium; D001554:Benzene