An Isolated Complex of Ethyne and Gold Iodide Characterized by Broadband Rotational Spectroscopy and Ab initio Calculations

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• 作者：John C. Mullaney ; Susanna L. Stephens ; Daniel P. Zaleski ; Matthew J. Sprawling ; David P. Tew ; Nicholas R. Walker ; Anthony C. Legon
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：September 17, 2015
• 年：2015
• 卷：119
• 期：37
• 页码：9636-9643
• 全文大小：336K
• ISSN：1520-5215

文摘

A molecular complex of C₂H₂ and AuI has been generated and isolated in the gas phase through laser ablation of a gold surface in the presence of an expanding sample containing small percentages of C₂H₂ and CF₃I in a buffer gas of argon. Rotational, B₀, centrifugal distortion, 螖_J and 螖_JK, and nuclear quadrupole coupling constants, 蠂_aa(Au), 蠂_bb(Au) 鈥?蠂_cc(Au), 蠂_aa(I), and 蠂_bb(I) 鈥?蠂_cc(I), are measured for three isotopologues of C₂H₂路路路AuI through broadband rotational spectroscopy. The complex is C_2v and T-shaped with C₂H₂ coordinating to the gold atom via donation of electrons from the 蟺-orbitals of ethyne. On formation of the complex, the C鈮 bond of ethyne extends by 0.032(4) 脜 relative to r(C鈮) in isolated ethyne when the respective r₀ geometries are compared. The geometry of ethyne distorts such that 鈭?*鈥擟鈥擧) (where * indicates the midpoint of the C鈮 bond) is 194.7(12)掳 in the r₀ geometry of C₂H₂路路路AuI. Ab initio calculations at the CCSD(T)(F12*)/AVTZ level are consistent with the experimentally determined geometry and further allow calculation of the dissociation energy (D_e) as 136 kJ molp>鈥?p>. The 蠂_aa(Au) and 蠂_aa(I) nuclear quadrupole coupling constants of AuI and also the Au鈥擨 bond length change significantly on formation of the complex consistent with the strong interaction calculated to occur between C₂H₂ and AuI.